A Newspaper has banned visitors to its website from commenting onstories about missing Madeleine McCann after it was bombarded with"spiteful and defamatory" comments about her parents.
The paper received hundreds of online messages, many of which callfor Gerry and Kate McCann to be prosecuted over the abduction …
Sony Music no Quiere Saber Nada de Lucero
Mexico --En un comunicado de prensa, la compania discografica Sony Music califico como "rumores sin fundamento" las negociaciones y posible contratacion de la cantante mexicana Lucero, y descarto que tales comentarios pudieran haber salido de algun funcionario de la misma disquera.
En el comunicado, Sony Music afirma: "Debido a recientes declaraciones de la cantante y actriz Lucero, algunos medios de comunicacion han afirmado que la novia de America forma parte de la compania Sony Music. Lo anterior es un rumor sin fundamento ya que entre la cantante y la compania disquera no hay ningun acerca-miento".
Continua el …
The son of Roger Clemens and two other minor league teammates were arrested early Sunday morning and briefly jailed after a disturbance at a restaurant in Salem.
In a news release, police said Koby Clemens, Mark Ori and Jimmy Goethals were arrested after police were called to the parking lot of a restaurant.
Clemens and Ori were charged with disorderly conduct. Goethals was charged with assault and battery.
All three were held in the Roanoke County-Salem Jail before being released on bond.
The three play for the Salem Avalanche, which played its final game of the season Monday in Lynchburg.
In a statement, the Houston Astros …
Firefighters were called to a house in Somerton last Fridayevening where a blaze had started after a plastic tray was leftunder a grill.
The fire at Kirkham Street set off smoke detectors in thebuilding and the …
Teemu Selanne broke open a scoreless game with a pair of goals inthe second period, and Paul Kariya ended a seven-game scoring droughtwith a goal in the third to spark the Anaheim Mighty Ducks to a 3-0victory Sunday against the visiting Los Angeles Kings.
Guy Hebert made 35 saves to earn his 20th career shutout and thefirst recorded by either team in this 29-game Southern Californiarivalry, which was born when the NHL expanded to …
PARIS (AP) — Decoding Rafael Nadal's self-evaluations can be a tricky proposition.
Listen, for example, to the way the top-seeded Nadal spoke about his game and his mindset after handling 37th-ranked Ivan Ljubicic of Croatia 7-5, 6-3, 6-3 Monday to reach the quarterfinals at the French Open, improve his record there to 42-1 and get closer to tying Bjorn Borg's record of six championships in Paris.
Nadal chastised himself for being "too anxious." He said he needs to "hit the ball with a little bit more conviction." Looking at the big picture, Nadal insisted: "The thing is, you have to be (a) realist, and today, I'm not playing well enough to win this tournament."
Maybe …
A news report says the Portuguese government has used its special voting rights to block Telefonica's euro7.15 billion ($8.72 billion) bid to buy Portugal Telecom's stake in Brazil's leading cell phone company Vivo.
Portuguese state-owned news agency Lusa said Portugal Telecom shareholders had voted Wednesday in favor of the sale of PT's 50 percent stake in Brasilcel, a holding company which in turn owns 60 percent of Vivo. Spain's Telefonica owns the other 50 percent of Brasilcel.
Government and Portugal Telecom officials could not immediately be reached for comment.
Lusa said the Portuguese state stepped in after the vote at a closed-door …
Chuck Swider is a Chicopee native who has seen the city go through many ups and downs.
He's hoping to give the community a shot in the arm with a new development project, slated to begin this spring, that could bring some new jobs to the city while bolstering efforts to spark improvement of Chicopee Center.
Construction is slated to begin on a two-story, 12,000-square-foot commercial building by April or May, on the corner of West and Center streets, adjacent to the route 391 on- and off-ramps. A specific end-use for the building has yet to be determined, but Swider is focused on exploring options in health care, and is now working to recruit tenants in a variety of medical …
Prime Minister Costas Karamanlis is due in Moscow on Monday for an official visit focused on expanding energy and military cooperation between Russia and NATO member Greece.
The three-day trip will include talks with Russian President Vladimir Putin amid ongoing negotiations for Greece to buy more than 400 Russian tanks.
Defense officials have announced few details of the possible deal, but state television and other Greek media said the government plans to spend euro1.2 billion (US$1.7 billion) on buying BMP-3M infantry fighting vehicles.
The negotiations will take place amid fresh strains between Moscow and NATO countries after Russia suspended …
Trenell Michael Adams and Roshawn Jones, both of Uptown, were charged with four counts of robbery and are also believed to have been involved in robberies in late July and early …
(This is not a legal transcript. Bloomberg LP cannot guarantee its accuracy.)
DAVID ROSENBERG, CHIEF ECONOMIST, GLUSKIN SHEFF & ASSOCIATES, TALKS ABOUT CANADA AT BLOOMBERG SURVEILLANCE
MAY 31, 2011
SPEAKERS: TOM KEENE, BLOOMBERG SURVEILLANCE HOST
DAVID ROSENBERG, CHIEF ECONOMIST, GLUSKIN SHEFF & ASSOCIATES
JULIA CORONADO, CHIEF ECONOMIST, BNP PARIBAS
8:07
TOM KEENE, BLOOMBERG SURVEILLANCE HOST: Joining us from Toronto where he rooted for [Rott Richard] for a kazillion years, David Rosenberg. David, good morning.
DAVID ROSENBERG, CHIEF ECONOMIST, GLUSKIN SHEFF & ASSOCIATES: Hi, Tom.
KEENE: …
CAIRO (AP) — Members of an ultraconservative Muslim sect clashed with villagers south of Cairo over demands that a liquor store and coffee shops be closed, officials said Tuesday, a sign of the increasing assertiveness of the fundamentalist Salafi movement.
One villager was killed and eight others were injured in the armed clashes, which erupted late Monday in the village of Kasr el-Bassil in Fayoum province, a security official said.
The fighting broke out after Salafi followers ordered the owner to close the liquor store and coffee shops as they try to forcibly impose their strict interpretation of Islam by banning the drinking of alcohol.
Salafis were tolerated as a …
The Chicago Plan Commission on Thursday endorsed construction of acombined office and residential high-rise on Wacker Drive that wouldbecome Chicago's eighth-tallest building.
The commission backed a proposal from the engineering and designfirm Teng & Associates Inc. for a 69-story building at 111 W. Wacker,the southwest corner of Wacker and Clark. At 867 feet, the buildingwould place behind the 900 N. Michigan tower and ahead of Water TowerPlace in the city's height standings.
But its greater significance could be as competition for theproposed Trump Tower Chicago just four blocks away at 401 N. Wabash,the home of the Sun-Times building. A venture of New York developerDonald Trump and Hollinger International, owner of the Sun-Times, hasproposed an 86-story building that measures 1,125 feet, good forfourth place in Chicago.
Although the Trump project would be much larger, both buildingshave large office components and floors devoted to luxury residentialunits with premium views along the Chicago River. Trump already hashis city approvals, while 111 W. Wacker still must pass through theCity Council.
Trump has no tenants committed to his project, but 111 W. Wackerhas one, its own developer. Teng told real estate agents it plans tomove into the building from its current headquarters at 205 N.Michigan.
The building would hold 320,000 square feet of offices on floors10 to 24. Above that base and taking a more slender form would be thefloors for 240 residential units. The lower floors and someunderground space would hold parking for 512 cars, a large allotmentintended to provide some public parking as well as serve theresidents and office workers.
The plan commission, which must approve large-scale developmentsbefore they come before the City Council, agreed to change zoning onthe property so Teng could build a larger building than the currentzoning allows. In exchange, Teng agreed to provide public amenitiessuch as a winter garden and landscaped terrace with a river overlook.
TOKYO (AP) — Japan officials say radioactive iodine detected in drinking water for Tokyo and other areas.
PERTH, Australia (AP) — Former Liverpool star Robbie Fowler has dispayed his anger with Fernando Torres for leaving the club by mockingly wearing one of the Spaniard's No. 9 jerseys.
Fowler, who plays for the Perth Glory in Australia's A-League, donned the shirt Friday as part of a fundraiser for Queensland state flood victims, saying "there is nothing wrong with the front of the shirt, it is the name on the back."
Fowler, who scored 183 goals in 367 games for Liverpool, added: "it is quite apt to wear it for a worthy cause as it is something myself or any other Liverpool fan wouldn't be seen in."
Torres is set to make his Chelsea debut Sunday against his former teammates at Stamford Bridge.
Working in investors' best interests
REGARDING GET SMART WITH YOUR money" (by Ian Davidson, CAmagazine, January / February 1999, p. 26): I am an investment adviser with Nesbitt Burns in Winnipeg, and I take offense to your article. I assume part of my annual CA fees go to covering the cost of this magazine, and that the information in it would be objective and unbiassed.
The author makes some very good points. Asset allocation and time not timing - in the market are key investment decisions. Also, his recommendation to hold equities as an inflation hedge, and because they are tax efficient, is right on the money (though I still come across clients whose CAs have recommended they invest in GICs and / or bonds).
However, I question the author's objectivity, since the company for which he works, the Equion Group, is part of the Assante Group. Assante does investment counselling; is there no conflict of interest here? Optima is also mentioned; that company manages Equion's money, and it is also under the Assante umbrella, yet there is no mention of this in the article. The author implies Optima manages his own money; is he required to use them? This article appears to be a great piece of advertising for his best interest.
As for a broker's best interest, while it is true they sometimes ask their clients to make quick investment decisions, the author implies that advisers have not taken into account their clients' objectives and that a decision has to be made there and then. I do not believe this to be correct.
The author states that a "broker cares about declines and gains; he or she makes money when markets rise or decline." This implies that brokers have no concern for their clients, that they just want to make money for themselves. Yet I find the best way to make money is by serving my clients' interests; brokers are well remunerated by a long relationship with their clients and many referrals. How long does the author think brokers would be in business if his statement were true?
He says the securities commission is encouraging fee-based business because "the investment adviser is not encouraged to make unnecessary trades." This again implies we are not working in our clients' best interests. Though this sort of behaviour should not be tolerated in any profession, unfortunately, it does occur in all professions. But it is the exception, not the rule.
The author concludes that managed money is the solution. But shouldn't such conclusions be made based on what's best for individual clients? Shouldn't investors seek advice from a professional who isn't limited to the products he sells?
The article seems to imply that CAs cannot - and do not have the time to - make good decisions themselves. It is articles like this that give our profession a bad name; how can we expect others to respect what we do if we do not even respect ourselves?
Before this, I had never written to the magazine in response to an article (these are my personal opinions, not necessarily those of my company); I hope never to again. But ever since I joined this business, people have asked me why I would leave such a well-respected profession for this one. Now I know where those people get their information: from our own industry.
It appears this article is nothing more than a piece of advertising and that the author is in conflict of interest. Since he is a CA, shouldn't there have been more disclosure?
I hope that no more of my funds go toward others' advertising.
Joe Fiorentino, CA Winnipeg
BUY-AND-HOLD WORKS
INTERESTING ARTICLE IN THE JANUARY / February issue of CAmagazine ("Get smart with your money," p. 26). 1 guess you paint all brokers / investment advisers with the same brush. I did not see any mention of the innovative fee-based products that are being offered by many of the major investment dealers, nor did I see any mention of costly, restrictive, underperforming DSC mutual funds. On a positive note, you will be happy to learn that many investment advisers like me offer - and prefer - to work on a fee basis. Clearly, the trend in our industry is toward (low) fee-based products.
One final thing. The reason for the lack of "sell" recommendations by analysts is that stocks are meant to be bought and held, not bought and sold. An investor should not sell a stock every time the company has a bad quarter, nor would it be prudent for an analyst to recommend such a strategy. Businesses do not operate in an environment that supports straight-line growth. Stocks are volatile, as are business conditions. While aggressive trading has become popular with on-line traders and many institutions (as demonstrated by portfolio turnover figures and trading volume reports), clearly, individuals should strive to buy good companies and hold for the long-term. Buying and holding excellent businesses has certainly worked out well for Warren Buffet, and it also works well for the individual investor.
Rick Smerchinski, CFA, CA Kitchener, Ontario
CA EMPLOYABILITY
HAVING READ MICHAEL KWEK S LETTER IN November's CAmagazine ("CA employability," p. 6), I recall the struggle that I, too, had in going through the CA program. In 1986, in Concordia University's undergraduate business program, I applied to more than 25 CA firms. The result? Zero interviews. I realized that my marks, experience and resume were not up to standard, so I pounded the pavement and landed a part-time job in the accounting department of a major multinational food company. The following year - still with average marks, but with some good work experience and a revamped resume - I landed a summer position with a medium-sized CA firm in Montreal. I then did some networking, and was offered a position in the smallbusiness department of one of the Big Six accounting firms in Toronto. Four years later, after internal transfers and working with the human resources department as well as with the partners, I passed the UFE on my first attempt.
Hard work and marketing yourself is just as important as getting good grades. Take another look at what you have to offer. Get yourself involved in university organizations, volunteer at tax clinics, speak to a career counsellor about your resume and job interview skills. I have seen the big CA firms hire non-business students over business students because they have something positive to offer. If you are still not able to land a position with a CA firm, then so be it. Someone out there will recognize your efforts and employ you. Good luck.
Sam Chan, CA Toronto
REALITY CHECK
SURELY GERARD BERUBE'S COLUMN, "REmove RRSP limitation?" (Off the Record, CAmagazine, December 1998, p. 9), is in jest. Perhaps the author has spent too much time with government economists and is, therefore, out of touch with reality.
The crisis in the value of the Canadian dollar is exactly why a prudent investor wants to get his assets into non-Canadian dollar securities. It is not the cause of the fall of our dollar but, rather, a reaction to it. The author seems to imply throughout the piece that a relaxation of the 20% limit for RRSP foreign investments would bring the Canadian dollar down. Perhaps that's where the value of the Canadian dollar should be, based on our economy, tax structure and productivity.
Berube's statement that some people are "waiting for proof that foreign investment means increased returns" is ludicrous in view of what has happened over the past few years. Does he not read the newspaper?
Those who hold market investments in their RRSPs would have loved to have had the freedom of choice to invest wherever they desired over the past few years. If the author himself follows the ideas that are expressed in his article, it is unlikely that his retirement income will be as good as it could be.
The tax issue is a red herring. If a taxpayer contributes $100,000 to an RRSP over his working career and it grows to $1,000,000 over that period, where is the loss of tax dollars to Canada? The investor may have deferred $50,000 on the contributions and $450,000 on the growth during that period, but he'll pay the $500,000 back on the withdrawals.
But tax is really the issue. It is the profligate spending by successive Canadian governments that has raised Canadian taxes to the highest level in all of the world's developed nations. Why should we taxpayers not do as well as we can with our investments? To what level will the confiscatory taxes rise?
If the bureaucratic and political waste in government were to stop, our dollar would recover to a more reasonable level. The investors cannot be blamed for the fall of the Canadian dollar. Investments in today's world are global, and Canadians should be allowed to invest in a global strategy. After all, Canada expects the rest of the world to invest in us and trade with us - hopefully to everyone's benefit.
Let's stop looking at this issue in a parochial manner and get on with the new century.
David W.R. Stevenson, FCA St. Catharines, Ontario
LACONIA, N.H. (AP) — Former Boston Red Sox manager Terry Francona could have a new job in New Hampshire — if he's willing to work for $6,000 per year.
The Laconia Muskrats of the New England Collegiate Baseball League faxed a job offer to Francona's agent immediately after he was released from his contract with the major league club last week, but haven't heard back.
Muskrats owner and general manager Noah Crane says he's included some unique benefits in the offer, including a parking spot; 25 percent off at a burrito restaurant; a free gym membership; and 25 tokens to an area arcade.
The New England Collegiate Baseball League has 12 teams. The Muskrats finished the regular season 18-24 before advancing to the championships, where they lost to the Keene Swamp Bats.
Objective: In subjects with borderline personality disorder (BPD), compared with subjects who attempted suicide, to review neuropsychological (NP) function that may predispose to suicidal behaviour along a continuum of high and low lethality.
Method: We undertook electronic searches of MEDLINE, PsycINFO, EMBASE, Biosos Reviews, and Cinhal. The searches were restricted to English-language publications from 1985 onward. The search terms borderline personality disorder, suicide, suicide attempt, self-harm behaviour, neuropsychological, executive function (EF), neurocognitive, and neuropsychological function produced 29 neuropsychology studies involving BPD and 7 neuropsychology studies of suicide attempters, regardless of psychiatric diagnosis.
Results: Of the BPD studies, 83% found NP impairment in one or more cognitive domains, irrespective of depression, involving specific or generalized deficits linked to the dorsolateral prefrontal and orbitofrontal regions. The functions most frequently reported (in 71% to 86% of BPD studies) are response-inhibitory processes affecting executive function performance that requires speeded attention and visuomotor skills. Decision making and visual memory impairment are also most frequently affected; 60% to 67% of BPD studies report attentional impairment, verbal memory impairment, and visuospatial organizational impairment. Least affected processes in BPD appear to involve spatial working memory, planning, and possibly, IQ. The similarities in NP deficits found in BPD and suicide-attempt studies involve decision making and Trails performances. BPD studies, however, reflect more frequent impairment on the Stroop Test and Wisconsin Card Sort Test performance than the suicide-attempt studies, whereas verbal fluency appears to be more frequently impaired in those attempting suicide.
Conclusions: Impaired EF and disinhibitory processes, as indicated by verbal fluency, Trails, and Stroop performance, primarily associated with dorsolateral prefrontal cortical regions may represent a dominant executive pathway to suicide attempt. A primary motivational inhibitory pathway involving conflictual, affective, and reflexive decision-making processes associated with orbitofrontal brain regions, in combination with significant cognitive rigidity, may influence the repetitive expression of self-harm or low-lethality suicidal behaviour. The hypothesis of a specific trait-like cognitive vulnerability for suicidal behaviour involving dysregulatory, disinhibiting pathways awaits confirmation.
(Can J Psychiatry 2006;51:131-142)
Information on funding and support and author affiliations appears at the end of the article.
Clinical Implications
* Deliberate and automatic neural processes, in combination with other risks, may yield unique pathways to suicide attempt and self-harm.
* The notion of willful, deliberate self-harm behaviour in some patients may have to be reconsidered.
* Greater clinical recognition and accommodation of neurocognitive impairments in paitents with BPD warranted.
Limitations
* The paucity of comprehenisve NP studies of suicide makes comparisons with other populations preliminary and exploratory.
* The clinical significance of NP findings in suicidal patients awaits further clarification.
* The influence of ADHD-LD comorbidity on the NP performance of suicidal patients requires further understanding.
Key Words: neuropsychological, suicide attempt, borderline personality, executive function
The NP study of suicide remains in its infancy. A growing interest is emerging, however, in the neuropsychology of BPD. BPD is associated with suicidal behaviour, and hence, an understanding of the neuropsychology of BPD may lead to a greater understanding of the neuropsychology of suicidal behaviour. NP studies to date have provided inconsistent results and (or) results that overlap with other clinical disorders. These developments raise questions about the specificity and stability of these NP deficits and lead one to wonder whether they are the causal organic antecedents to psychiatric disturbance (1,2), the result of environmental vulnerabilities (3-5), some complex combination (6-8), or the result of the illness itself. Longitudinal studies, as yet unavailable, may provide more definitive answers to these important causal connections. Recent investigations combining NP performance with structural and functional neuroimaging have localized the underlying neural pathways and biological mechanisms involved (9-17). While extensive NP research has been conducted on schizophrenia and ADHD, the role of cognitive dysfunction in the causation of BPD, and suicidal behaviour more generally, remains unclear (18,19).
One in 10 patients with BPD will complete suicide; 75% will engage in self-injurious behaviour, a known risk factor for suicide attempt (20-23). Because the clinical distinctions between self-harm and suicidal behaviour remain ambiguous (24,25), the role of cognitive impairment as a potential risk factor for suicidal behaviour remains largely unknown. Currently, few investigations exist examining the associations between cognitive impairment and suicidal behaviour, defined as self-directed injuries with at least some intent to die (26). Could dissociable cognitive processes associated with self-harm and suicidal behaviour provide clinicians with additional information to more reliably predict and manage these behaviours? This review of NP function in BPD and in suicide attempts regardless of psychiatric diagnosis examines the role of cognitive dysfunction in the causation of suicidal and self-harm behaviour.
An examination of cognitive dysfunction in BPD, regardless of the lethality of suicidal behaviour, and its comparison with cognitive dysfunction in suicide attempters in general, may yield distinct patterns of NP impairment. A greater understanding of suicidal and self-harm behaviour can inform subsequent research and clinical practice.
Search Methods and Results
We searched MEDLINE, PsycINFO, EMBASE, Cinhal, and Biosis Reviews for articles published in English from 1985 onward. Search terms were borderline personality disorder, neuropsychological, suicide, executive function, neurocognitive assessment, neuropsychological function, and suicide attempt. Studies were included if they involved any number of commonly used standardized NP tests or batteries in samples of BPD and suicidal populations. Manual searches of the authors' reference lists produced additional relevant literature. The search produced 29 NP investigations involving BPD as a primary or secondary comorbid disorder. Only 7 published studies of NP function in suicide attempters were located (27-33).
Overview of NP Studies of BPD
NP studies of BPD suffer from the methodological challenges related to controlling for past or current alcohol or substance abuse, comorbid anxiety, depression, ADHD, LD, and medication effects-all known to potentially affect neurocognitive test performance (34). Generalized and domain-specific deficits were affirmed in 24 of 29 published studies located in this review, despite the wide variation in samples studied (see Note). Studies primarily included convenience samples of women aged 18 to 50 years, with mixed-sex samples represented in 7 studies and all-male subjects represented in only 3 investigations. To date, slightly more inpatients are represented than outpatients, with some investigators including both. The controlled studies were matched for age, education, sex, and less frequently, IQ-all believed to affect NP function. Only 5 investigators (19,35-38) failed to find significant NP impairment in BPD.
First-Generation Studies: NP and BPD Psychopathology Correlates
First-generation studies were exploratory for the presence or absence of NP abnormalities in BPD (35,39-44) associated with personality and psychopathology measures. These important studies made use of comprehensive NP batteries, but they were characterized by very small samples with no current Axis I comorbidities. These early studies ranged from those without a control group (35,42) to others with carefully matched healthy control subjects (40,41,43,44). Only Burgess (39) and van Reekum (43) made use of psychiatric comparisons. Reports of general intelligence, attention, memory, and motor deficits were documented by some investigators (39,41,43,44). EF was described as abstract thinking, problem solving, and complex visual or verbal information processing.
Second-Generation Studies: Biological Correlates of EF in BPD
Building on first-generation findings, incorporating data drawn from populations having brain lesions and from healthy populations, and using modern neuroimaging technology, second-generation investigators focused on selective attentional and (or) EF tests with known localizing value to specific brain regions. These recent technological advances are strengthening support for the view that biological underpinnings are implicated in the disorder (4,19,37,45). Greater conformity to standardized research diagnosis; use of healthy, psychiatric, and comorbid control subjects; larger samples; use of convergent computerized and manual NP tests; and greater attention to relevant confounds generally characterize these investigations (3,18,36,38,46-57). However, the inclusion or exclusion of subjects with mild neurologic comorbidity (that is, with TBI, ADHD, LD, or epilepsy) continues to vary across studies (5,19,37) and detracts from the comparisons among samples. To date, few investigators have attempted to disentangle this significant confound (3, 5,18,43,47,51,58), which is related to both BPD diagnosis and EF dysfunction.
In 1 of 2 reviews, O'Leary (59) reports on 4 comprehensive studies, including her own, that found impairment in simple and logical verbal memory and visuospatial organization (40, 41,44,60). All 4 confirm deficits in complex visual memory, with 2 of the 4 also identifying lowered IQ (41,44). Because studying IQ in general remains controversial (61), many investigators have not measured or reported on it. In a review of 14 studies, Monarch and others note a lack of comprehensive NP investigations of BPD (42); these often involve a single domain, with attentional tests appearing to lose favour to specific EF measures. More refined hypotheses and tests with greater localizing value may have led to these trends. As well, many attentional processes are believed to underly EF function (62). Findings of impulsivity, verbal memory, and visuospatial EF impairment were evident in Monarch's review. She subsequently found WAIS Digit Symbol scores (a measure of visuomotor speed, attention, and intelligence) to be 3 to 5 SDs below historical comparison-group scores in her own study. Recent investigations demonstrate variable exclusion of subjects with current Axis I and II comorbidity; however, representativeness is questionable because it is unlikely that a "pure" BPD condition exists (8,63). The exclusion criteria may explain the small samples studied.
NP Findings in BPD
BPD and General Intellectual Function
The WAIS-R is the most comprehensive test of general intellect, whereas the NART (64) is widely used as a verbal estimate of premorbid intellectual ability. The Digit Symbol, Block Design, or Picture Arrangement subtests of the WAIS also represent intelligence estimates. Three comprehensive WAIS assessments found subjects with BPD to be more intellectually compromised than were control subjects (40,41,44); normal findings were reported by Cornelius, who had no control group (35); and Driessen, who, after controlling for depression with BDI scores, did not find any difference in IQ (19). Using 4 WAIS subtests, Irle and others found significant impairment in verbal IQ, and more severe performance impairment on the Block Design (4). Using IQ estimates, Burgess (39) and Bergvall (56) also endorsed lowered verbal IQ in subjects with BPD. However, normal IQ in BPD was also reported (3,19,36,37,48,50,51). These inconsistencies suggest that the full-scale WAIS may be more sensitive or that the negative findings associated with IQ estimates may reflect the classic heterogeneity of BPD. Overall, performance IQ seems to be more consistently affected than verbal IQ, which may reflect the visuospatial impairment found in individuals with BPD. Overall, 54% of studies found lower IQ in subjects with BPD, suggesting impaired premorbid functioning. Many researchers set an IQ level in their inclusion criteria and thus might have erroneously eliminated those most affected.
Attention and BPD
Although lacking a clear definition, 2 aspects of attention-that is, automatic or reflexive processes and voluntary controlled processes-are well established. Sustained attention, such as occurs in vigilance, and the notion of a time-limited capacity to remain vigilant are known to be affected by depression, fatigue, ageing, and brain damage (34). Selective attention or concentration involves focusing on relevant stimuli while ignoring irrelevant stimuli. Slowed processing underlies many attentional disorders, which can have broad effects on all aspects of attention. Fifteen studies examined selective and sustained attention by means of the CPT, ANT, computerized BWM test, or Digit Symbol modalities; of the 15 studies, 60% found general or specific impairment (3,4,18, 40,42,47,49,53,54), with negative results also reported (19, 38,41,44,45,65).
Posner and others compared negative affect and effortful control in BPD patients and healthy and temperamentally matched control subjects, using a reaction-time task assessing 3 attentional networks (alerting, orienting, and conflict resolution) (53). Only effortful control was related to ANT conflict scores, indicating a specific abnormality in BPD, irrespective of temperament, in the area of conflict resolution and, more generally, cognitive control. The conflict network is associated with the subcortical anterior cingulate gyrus, which normally develops between ages 2 and 7 years, a time when many BPD patients report periods of abuse or neglect. Paris and colleagues reported sustained attentional impairment in 41 school-aged children with similar symptoms (described by the authors as "borderline pathology of childhood"), compared with psychiatric control subjects (3). After controlling for ADHD and other comorbidities, children with BPD demonstrated poorer orientation to task, slower reaction time, inconsistent responses, and greater risk-taking. Zelkowitz and others further compared the predictive effects of attentional and EF deficits with histories of sexual abuse and violence in predicting BPD diagnosis (4). These authors found that environmental trauma explained 25% of the diagnostic variance and that attention and abstract thinking deficits contributed 33%. Attentional impairment on Digit Symbol and Digit Span tests, a measure of gross attention (4, 39-42,44), has also been reported in BPD. In 30 women with BPD and severe histories of sexual and physical abuse, IrIe and colleagues found marked selective attention to be associated with reduced hippocampal volume and exposure to traumatic stress (4).
Travers and King studied a sample of 80 subjects with BPD, of whom 66% were confirmed with organic impairments (that is, a history of significant head injury, encephalitis, epilepsy, ADHD, or LD). They found greater attentional and EF problems and substance abuse histories in the BPD organic subgroup but no visual or verbal memory differences among subjects in either organic and nonorganice groups (18). These findings suggest that organicity does not account for all observed NP deficits. Depression and anxiety also had little effect on the test results. Attention and verbal fluency scores correctly predicted 71.3% of group membership.
Of 15 studies, 9 (60%) identified significant, sustained, selective, or highly specific attentional impairment in BPD. Do attentional difficulties further reflect the presence of dissociative phenomena commonly experienced by some patients during acts of self-injury? Parallel visuospatial and spatial reasoning, figural memory, immediate verbal memory, and selective and sustained attentional deficits have recently been confirmed in a study of subjects suffering from depersonalization (66). However, these subjects performed normally on the WCST, Trails Tests, IQ tests, and Stroop tests and thus mirrored only some of the NP deficits associated with BPD.
Verbal Memory in BPD
Memory impairment is not unique to BPD and, when seen in BPD, is often attributed to comorbid depression. Of 12 studies reviewed, 8 (67%) found verbal learning and memory impairment in comparisons with healthy (40,42,44,49) and psychiatric (4,18,39,46) control subjects. To clarify the influence on verbal memory of comorbid BPD in clinical depression, Kurtz and Morey tested 20 patients with depression and comorbid BPD, 20 patients with depression only, and 20 healthy control subjects (46). Despite similar depression severity, patients with comorbid BPD showed poorer verbal recall and recognition memory than did depression-only patients and healthy control subjects, suggesting that BPD is associated with cognitive deficits beyond those caused by depression. However, in a similar 3-group comparison with patients having schizophrenia and comorbid BPD, Lysaker and others did not find any relation between comorbid borderline traits and neurocognitive function (65). O'Leary's analysis of medicationfree BPD patients indicated significant impairment in immediate, delayed, and distorted verbal recall, but memory improved with cueing (44). Monarch and others also validated significant verbal memory impairment, using historical control subjects (42). Burgess used 6 subtests of memory in a sample of 27 BPD patients who were compared with control subjects having schizophrenia and control subjects with depression and found an association between deficits in attention and memory and self-injury in the BPD group (39). This association was not found within the comparative schizophrenia group who self-harmed. Subjects with BPD had more delayed and omission memory errors than either the schizophrenia or depression groups. Depression was not correlated to self-harm in any of the clinical group comparisons. Irle and other also found logical verbal memory to be impaired (4), but stringent control for the effects of depression was not possible. In most of the studies reviewed, verbal memory deficits in BPD appear to exist beyond those attributed to depression. These impairments may be secondary to executive dysfunction such as difficulties with attention, working memory, strategy formulation, and the inhibition of competing recollections (62,67-69).
Visual Memory in BPD
Visual memory impairment is reported in 71% (10 of 14) of BPD studies reviewed (4,18,40-44,49,52,60). In addition to being more prevalent than verbal memory impairment, right hemispheric visual memory appears to be more markedly impaired in these samples (49). The ROFC requires subjects to reproduce 18 elements of a complex geometric figure from memory, without warning and after a 1- and 30-minute delay. The Rey Copy portion of the ROFC measures figurai detail and the Recall component involves spatial memory for location. Seven studies found impairment in both Copy and Recall conditions (4,18,40,42,43,49,52), with Recall-only difficulties reported by O'Leary (44).
Irle and others (4) found that 30 abused women who suffered from BPD with Axis I and II comorbidity had 11% smaller right parietal cortex and 17% smaller hippocampal volumes, compared with control subjects. Greater trauma and marked deficits in immediate visual memory and visuospatial cognition were associated with reduced hippocampal size. Comorbid anorexia, current or past alcohol abuse, and depression did not predict NP impairment or volumetric change. While not differing on brain volumes, subjects with BPD and comorbid PTSD performed more poorly on NP measures. There was no difference in brain volumes of subjects on antidepressants, benzodiazepines, or neuroleptics, compared with subjects not on these medications. Because 26 of the Irle study's 30 subjects met criteria for depression, the effects of this comorbidity cannot be discounted; however, she suggests that BPD is a neurodevelopmental deficit of the right hemisphere with subtle NP impairment. This study lends support to Driessen's earlier findings of hippocampal reductions in BPD irrespective of PTSD comorbidity (13). Dinn and others administered an extensive NP battery to 9 female medicated inpatients with self-harm, suicide attempt, and schizoaffective and PTSD comorbidity (49). The same tests were administered to a second sample of 139 university students with BPD features. The students exhibited the same NP impairment as the patients, although the deficits were less pronounced. Contrary to Dinn's initial hypotheses, nonverbal memory, nonverbal EF, and visuospatial ability associated with prefrontal regions were more strikingly implicated than the expected orbitofrontal functions measuring impulsivity, social awareness, and response inhibition. Dinn argued that medication should not have contributed so selectively to nonverbal skills while sparing verbal skills. Separate analyses controlling for depression, substance and alcohol abuse, and anxiety did not alter the findings. Immediate and delayed visual recall was also supported in a study of a small unmedicated sample (41); however, BPD patients had greater learning disability, developmental delay, and lower full-scale IQ than control subjects, despite similar years of education. In summary, visual memory impairment reported in these and other studies seems consistent with the clinical observations of BPD patients' perceptual distortions in many aspects of daily living. Reduced hippocampal volumes in BPD (4,19) may contribute to greater visual memory impairment.
Visuospatial Processing
Visuospatial integrity has been tested in 17 BPD investigations, of which 11 (65%) implicate impairment as measured by the Rey Copy, Block Design, Corsi, Embedded Figures, Digit Symbol, and Picture Arrangement tests. Efficient Rey Copy depends on organization, intact visual information processing, and visual memory (61). Deficits for processing visual information on the Rey Copy have been strongly associated with BPD (18,40-44,49,52) and confirmed by other tests of visuospatial impairment (4,54,55). Visuospatial scanning deficits, may affect the timed performance on tests of EF (70).
EF and BPD
Perhaps not surprisingly, as many as 86% (12 of 14) of reviewed studies confirm a degree of EF impairment in BPD. EF involves insight, self-awareness, reflection, initiation, evaluation, and control of thought and behaviour. Interpretations of abnormal EF findings are challenging because these tests frequently involve multidimensional components of attention, memory, response inhibition-suppression, and visuospatial ability. EF impairment is most frequently associated with, but not limited to, dorsolateral PFC localization. While the interrelated functions of the frontal lobes associated with EF remain poorly understood, visual performance abilities, most frequently affected in BPD samples, seem to be well-supported to the frontal regions (67).
EF: Tests of Speeded Visual-Motor Skills. Digit Symbol Coding and Trail Making Test Parts A and B are widely used, nonspecific, timed measures of psychomotor speed, attention, mental flexibility, visual conceptual, and visuomotor tracking and are considered highly vulnerable to brain injury (61). Of 7 BPD studies, 5 (71%) employing Trails tests, indicate impairment (18,42,43,49,50). Lezak suggests that slow Trails performances at any age on one or both of Parts A and B does not differentiate whether the problem is one of motor slowing, coordination, visual scanning, poor motivation, or conceptual confusion (61). While Trails performance can be affected by visuospatial impairment (71), the time to complete makes it sensitive to attentional and psychomotor difficulties, as also measured by the Digit Symbol test. Digit Symbol impairment, also evident in 7 BPD investigations (35,40-42,47,59,60), is believed to be unaffected by intellect, memory, or learning. Motor persistence, sustained attention, response speed, and visuomotor coordination play important roles in a person's normal Digit Symbol performance (34). Poor EF may be the result of significantly slowed psychomotor speed in combination with impaired attention (72).
EF: Tests of Decision Making and Planning. Impaired anticipatory planning in BPD has been confirmed in some studies (18,48,49,51) but not in others (36,37,56). We located only 2 studies of decision making in BPD (48,51). In both, decision making and planning impairment were implicated. Only 3 of 6 studies examining spatial working memory, believed to affect decision making, found impairment in BPD (49,51,54). Similarly, planning deficits have been inconsistently reported in only 57% of the BPD samples reviewed. Bazanis hypothesized that self-damaging behaviour may reflect an impairment in decision making and planning (48). He tested 42 selfharming BPD patients who were without TBI, substance or alcohol abuse, or depression, nor were they receiving medication exceeding 300 mg chlorpromazine equivalents. Of the sample, 98% were engaged in self-harm and suicide attempt. This group was compared with 42 matched nonclinical control subjects. Visual recognition memory and aggression measures were also administered. Only impairments in decision making and planning were noted. BPD patients took longer to decide, selected the most unlikely outcomes, and placed earlier bets on whether their choices were correct, demonstrating disinhibited responses. Planning deficits indicated longer deliberation times, more attempts, and longer latency for first solution attempt. Bazanis described these deficits as localized to the orbitofrontal and dorsolateral frontal brain regions and speculated that a general aversion to delay might be an important feature of BPD. Dowson and others confirmed longer deliberation times on a similar computerized decision task (73).
EF: Abstraction and Cognitive Flexibility. The WCST (74) assesses the ability to form abstract concepts and to shift and maintain cognitive set. It also measures perseveration and learning efficiency. Of 13 BPD studies, 8 (62%) reported impairment on either the WCST (3,5,43,45,49,50) or the ID/ED (54,56). Lenzenweger and others tested 24 women with BPD on sustained attention, spatial working memory, and EF-together known as "controlled information processing" (45). Personality, anxiety, depression, and a computerized spatial working memory test, as well as the WCST, were administered. Three of the 4 WCST subtests were impaired, with no differences in spatial working memory shown between subjects and control subjects. Medication, emotional affect, depression, and anxiety did not alter the results.
In a rare antecedent NP study of BPD, Paris and others studied 94 school-aged children in psychiatric day treatment; 41 demonstrated similar symptoms (described as "borderline pathology of childhood") (3). No sex differences were found on any NP measures. IQ was in the normal range, and subjects did not differ from control subjects on neurologic soft signs or the ROFC Copy or Recall tests. Significant differences on all scales of the WCST were found in children with BPD symptoms, who required more trials to complete and demonstrated more perseverative responses and errors and fewer conceptualizations, compared with their psychiatric peers. Owing to high CD comorbidity, CD was entered as covariate but did not alter the findings. Paris suggests that NP impairment in children with BPD symptoms mirrors that of adults with BPD. Preservative errors and delay in shift set on the WCST are associated with dorsolateral PFC function (5,75).
EF: Response Inhibition. Of 14 BPD studies, 12 (86%) implicate dysregulated control (stop-start) mechanisms involving motor, attentional, and other impulsive cognitive processes (36-38,41,43,45,47,48,51,54-56). Investigators who found no other NP impairment (36-38) discovered dysregulation on the timed Stroop, which requires both attention and impulse control. The Stroop (76) measures the ease with which a person can shift his or her perceptual set to conform to changing demands and suppress a habitual response in favour of an unusual one. A markedly slowed naming response when a colour word is printed in a different colour has been attributed to a slowed conflict response, a failure of response inhibition, impaired selective attention and (or) a difficulty in ignoring distraction (61). Only 2 investigators report intact response-inhibition behaviours on the GNAT (38,49). Verbal fluency, a measure of response initiation, has been infrequently tested in only 5 BPD studies, with 3 (60%) reporting impairment (18,49,59). While more fluency studies in BPD are warranted, fluency deficits may contribute to a lack of initiative and self-direction, impaired problem solving, and the excessive interpersonal dependency commonly observed in patients with this disorder. Some BPD patients' psychomotor regulation difficulties may further prevent them from acting on any newly acquired insight. These dysregulated arousal and (or) inhibition responses may explain the commonly experienced "disconnect" between knowing what is right to do and yet not being able to follow through, despite intentions. Impulsive personality traits, known to be high in BPD samples, do not consistently correlate with laboratory measures of response inhibition or attentional impulsivity (38,45,54,55).
EF: Spatial Working Memory. Only 3 of 6 BPD studies endorse difficulties with spatial working memory. Slower visual stimulus perception and working memory impairment were observed by Stevens in 22 women with BPD, in whom impulsivity, dissociation, and negative affect did not influence working memory performance (54). No NP scores were associated with depression. After controlling for depression and substance abuse, Dinn and others endorsed striking deficits in visual working memory, as well as slowed planning and set shifting typically associated with the prefrontal regions of the brain (49). Surprisingly, omission-only errors on the GNAT suggested no orbitofrontal involvement. In contrast, Berlin and Rolls found intact spatial working memory performance but deficient time perception in 19 self-harming women with BPD, in whom a faster subjective sense of time was related to behavioural impulsivity (55). Dowson and others also compared spatial working memory and decision making in 19 adults with ADHD, 19 subjects with BPD, and 19 nonclinical control subjects (51). Subjects with BPD demonstrated longer decision-deliberation times than both groups. No differences in spatial working memory were evident among the groups. Since comorbidity as well as any shared etiology between ADHD and BPD would have reduced the differences in neurocognitive performance, Dowson concluded that the results were substantial and significant. The dysfunction of working memory in BPD, while not extensively studied, may be the result of reduced PFC metabolism (11,14), but this requires further study.
In the only NP study comparing the 3 clusters with personality disorder on the basis of their EF, Besteiro-Gonz�lez and others found that cluster B personalities had better overall scores on all measures except the Stroop (38). The cluster A group performed most poorly on attention and concept formation, whereas reaction times on the Stroop were slower for the cluster B group. There were no differences among the clusters on any pathophysiological or personality measures, adding further weight to the observations of dysregulated control processes in BPD. Overall, 5 of 6 (83%) BPD samples showed impairment on the Stroop.
Summary of NP Correlates in BPD
A range of cognitive deficits in BPD appear to exist beyond the influence of depression, prescribed medication, and possibly, substance abuse. Unfortunately, only 5 of 29 studies stringently controlled for the presence of learning disability and ADHD (3,18,43,47,48). The most frequently compromised cognitive processes, as reported in up to 86% of BPD studies, involved dysregulated control mechanisms; these were followed by other EFs involving speeded attention, flexibility, and visuotracking abilities, as found in 71% of studies. Visual memory impairment was also evident in 71% of the BPD studies reviewed. Moderately compromised functions, evident in 60% to 67% of studies, appeared to involve visuospatial processing, verbal memory, abstraction, cognitive flexibility, and verbal fluency. The NP functions least affected in BPD appear to involve spatial working memory, planning, and possibly, IQ. Could lower IQ and smaller hippocampi compromise overall adaptation and coping and result in greater risk for the development of BPD, as has been suggested in individuals with PTSD (77,78)? Decision-making and planning functions may involve distinct processes, as inconsistent planning and consistent decision-making impairment was evident, albeit in few BPD studies to date. Several investigators have implied a level of discrete dysfunction in keeping with frontal function known not to dramatically disrupt NP performance (34).
While NP tests do not necessarily affirm localized brain dysfunction, examining relations among several related tasks with established sensitivity for a particular brain region provides evidence of the probable involvement of those structures (79). This impairment in NP function may be clinically significant, involving minimally one-half of all BPD samples reviewed. With as many as 86% of BPD samples demonstrating a range of EF impairment, more thorough cognitive assessments are needed when planning for effective treatment and recovery.
NP Findings in Suicide Attempters
EF Correlates of Suicide Attempt
Early investigators hypothesized that cognitively rigid individuals were more prone to suicidal behaviour (80,81) and poor interpersonal problem solving (82,83). This led investigators to selectively administer fluency and WCST measures. Surprisingly, we located only 7 NP studies of adult suicide attempters (see Note). However, learning disabilities in adolescents, involving psychomotor and visuospatial organization impairments that affect interpersonal relationships, have been associated with an increased risk of suicidal behaviour (84,85).
Suicide and EF: Verbal Fluency
Strong support exists for verbal fluency scores as an indicator of frontal lobe dysfunction (86,87). Verbal fluency reflects initiating processes and is reduced in patients suffering from depression and suicidality despite the challenge, due to the depressive state, of separating a willed lack of effort from an unwilled reduced capacity to make an effort. In 9 inpatient men with affective and adjustment disorder, Bartfai and others found reduced intellectual reasoning and verbal and design fluency 3 weeks following a suicide attempt, but they found no impairment in problem solving, planning, or cognitive flexibility (28). Fast inspection on the Porteus Maze planning task for the suicide-attempt group implicated impulsivity. Abilities to generate alternative problem solutions and new ideas were decreased in suicidal patients, independent of diagnoses and alcohol abuse.
In an fMRI study of verbal fluency in unmedicated suicide attempers suffering from depression, Audenaert and others found reduced blood perfusion in anatomically specific areas of the prefrontal cortex during letter and category fluency tests, along with poorer overall word production (32). More recently, low serotonin receptor binding was found in recent suicide attempters, but interestingly, serotonin was even lower in patients who had deliberately self-harmed (88). In a comprehensive comparison by Keilp and others of high- and low-lethality suicide attempters (27), high-lethality subjects performed more poorly on all tests of EF than did clinical and control groups; moreover, they were the only group to perform more poorly than healthy control subjects on tests of intellect, attention, and memory. High-lethality attempters were differentiated by their EF, whereas depression patients differed from the healthy control subjects on attention and memory. This suggests that executive impairment in suicide attempters exists beyond depression or depression severity. High-lethality attempters were specifically discriminated by letter fluency, selective reminding test, WCST failure to maintain set, and Trail A reaction time scores, suggestive of significant EF impairment. This study added to the evidence of fluency impairment associated with suicidal behaviour. Keilp argues that diffuse brain damage resulting from a lethal attempt does not appear to be a confounder, as tests representing diffuse brain injury did not show selective impairment (27).
Cognitive rigidity and other NP functions were comprehensively evaluated by King in a sample of 57 elderly medicated inpatients suffering from depression with and without suicide attempts (31). The only difference between attempters and nonattempters was that time and sequencing errors on Trail B showed an increase among attempters that appeared to worsen with age. Trails tests additionally assessed speed, visual scanning, new learning, mental flexibility, sequencing, and concentration (41). Ellis and others also report no differences between 20 suicide attempters, and 27 psychiatric nonattempters, with both groups scoring in the impaired range of standardized scores on several tests, despite similar depression severity (29). Thirty-five percent of the suicide attempters and 44% of the nonattempters in this study functioned well below normal on the PPVT, WCST, Trail making, and finger tapping tests. In contrast to most BPD studies, King's finding (31), and those of Ellis and others (29), support the influence of psychopathology on the NP results, independent of suicidal behaviour. Using a modified emotional Stroop test, Becker compared 31 recent suicide attempters with 31 control subjects who suffered from anxiety and depression but who had not attempted suicide (30). Suicide attempters were unaffected by negative, positive, or neutral words; however, a longer time to name the colour of suicide-related words indicated a highly specific attentional bias toward suicide stimuli. Severity of suicidal intent was positively correlated to this attentional bias after control for depression, anxiety, and hopelessness.
Suicide Attempt and Decision Making
Using the IGT, Jollant and others examined decision making in violent and nonviolent suicide attempters, a control group of normal subjects, and a control group of formerly nonsuicidal subjects with depression (33). All subjects were free of current Axis 1 disorder when tested. Both groups of suicide attempters scored lower than healthy control subjects on decision making, whereas violent suicide attempters performed more poorly than control subjects with nonsuicidal depression. Lack of other differences between the 2 groups of attempters, or between the 2 control groups, suggested that decision-making impairment in high-lethality attempters was independent of affective disorder and possibly represented a cognitive vulnerability for suicide. When substance abusers in both suicide-attempter groups and those on prescribed medication were removed from the analysis, similar findings prevailed. Decision-making scores were unrelated to age, education, intelligence, age at first attempt, number of attempts, or severity of intent. Decision making for all suicide attempters was positively correlated to affective lability (89), whereas decision making in nonviolent suicide attempters was associated with anger expression and hostility.
Comparison of NP Function in BPD and Suicide Attempters (Table 1)
In a comparison of NP findings among BPD and suicide attempter samples, verbal fluency was more frequently found to be compromised in suicide attempters than in subjects with BPD, while impairments in psychomotor performance (that is, Trails A and B), and decision making were found equally in both populations. Surprisingly, measures of abstract thinking and cognitive flexibility were relatively intact in suicide attempters (25%), whereas 62% of BPD studies indicated impairment according to the WCST. Subjects with BPD, however, were more frequently found to be impaired on the Stroop test, a measure of attention and response inhibition with frequent reports of slowed reaction or response times. While one must not assume that BPD samples encompass only those with self-harming behaviour, these divergent findings in the 2 populations may reflect unique cognitive processes distinguished by performance on the COWAT, WCST, ROFC, GNAT, and Stroop, as well as other inhibitory control processes that may be differentially engaged among those with and without a conscious intent to die. Behavioural dysregulation, implicated in 86% of BPD samples, involves a disruption of cognitive control associated with a general failure to modify action, thought, and feeling needed to conform to the social and intellectual requirements of a situation (90). These inhibitory EF deficits may act as important cognitive precursors to the self-harm behaviours seen frequently in BPD. Coolidge further suggests that these processes may be manifestations of genetically determined EF (91).
It appears that NP performance and suicidal behaviour may be independent of clinical depression, as reflected in most, but not all suicide-attempt studies, consistent with the trends in the BPD literature. The NP inconsistencies among high- and low-lethality attempters may mirror the clinical ambiguity so often associated with self-harm and suicidal behaviour. Decision making, found to be impaired in all suicide-attempt and BPD studies (33,47,48,73), may represent a shared inhibitory pathway leading to suicidal behaviour, but this requires additional study.
Implications
Three models have been proposed to explain dysregulated behaviour, distinguished by the degree of anxiety or arousal involved and by the temporal quality of the incentive (immediate or distal) (92-95). Behavioural control also depends on the positive or negative nature of the incentive. Briefly, the first model is an arousal model of disinhibition that involves reflexive or automatic alerting and attention needed to understand new information; underarousal leads to slowed information processing. A second model of executive inhibition requires a deliberate, thoughtful suppression of a previously learned inappropriate response to achieve a future goal. An action is suppressed and intentionally held in working memory (executive) as new information is received. Anxiety or fear is typically not activated in this case. The third, or motivational inhibition, model (96,97) proposes a "reactive" process to emotionally salient incentives, involving immediate punishment or reward to avoid high anxiety. Hypersensitivity to immediate rewards with an aversion to more distal future rewards, as well as an active avoidance of delay (anxiety), drive these motivational processes. Motivation, believed to be modulated by the hippocampus and amygdala, may involve slowed or variable motor responses and difficulties in motor control. Understandably, the integration of executive and motivational inhibition is closely linked to real-life behaviour (93).
These inhibitory models, activated by different regions of the brain, can guide an understanding of the predominant pathways that may lead to suicidal behaviour. One pathway to suicidal behaviour involving suicide attempt with intent may involve both arousal and executive inhibition deficits. These deficits are evidenced by low verbal fluency, slower information processing on Trails and Stroop tests, and conflict scores on decision tasks. A greater risk of acting on suicidal thoughts may be the result of inabilities to express and repress an inappropriate choice. Suicidal patients may demonstrate primarily arousal and executive inhibitory control deficits through perseverative nonsuppression of deliberate thought and action to end their lives. A compromised ability to generate and verbalize more creative problem-oriented solutions may lead to feelings of entrapment. Paradoxically, the decision to take one's life may reduce anxiety.
Conversely, self-harm behaviour involving ambivalent or a lack of deliberate intent or forethought may involve another pathway of motivational inhibition associated with an immediate delay aversion to intense negative affect. Inability to endure a temporary, albeit intense, emotional state may reflect a propensity for immediate rewards and avoidance of anxiety with little regard for future consequences, irrespective of the number of past occurrences. Reflexive and repetitive self-harm behaviour, which for some provides a form of immediate emotional relief, may reflect these deficient reward-punishment signals. This motivational dysregulation may represent an important delay aversion pathway to self-harm. In BPD samples, impaired decision making involving temporal rewards or punishments on risky, uncertain outcomes, combined with executive inhibition deficits (indicated by higher Stroop and WCST scores), may interact to produce even greater behavioural and emotional dysregulation, resulting in reactive, avoidant self-harm behaviour. The potential involvement of this motivational pathway, believed to localize to the orbitofrontal regions with connections to the amydala and hippocampus (99-101), may challenge the notion of deliberate self-harm behaviour in BPD. These hypotheses examining causal pathways to suicidal behaviour require further examination and analysis but may provide a conceptual framework for subsequent study.
Conclusions
Cognitive impairment predominantly associated with, but not restricted to, the right frontal hemisphere (visual dominance) exists in BPD. The specific source, severity, and outcome of this impairment, however, remain unclear. Contrary to popular belief, these deficits, particularly in BPD, do not appear to be primarily the result of comorbid depression or of its severity. Whether BPD contributes to impairment beyond unrecognized comorbid ADHD or LD awaits further validation. One cannot ignore the consistency of this impairment across multiple domains, as understood by both first- and second-generation investigators. However, reports of clinical significance are noticeably lacking in the studies to date. Further research is therefore needed to clarify the extent of NP impairment that may contribute to the unique behavioural manifestations of BPD or the dimensional nature of suicidal behaviour. While cognitive impairment in BPD has been associated with the growing evidence of biological dysfunction, the direction of causation remains inconclusive. Perhaps most important, the outcome of this impairment on everyday function awaits confirmation.
It is evident from this review that not all individuals with BPD suffer from impaired cognitive and behavioural EF, which challenges the notion of a single causal pathway model. Nigg suggests that causal models do not have explanatory power unless they capture the broad essence of the disorder as it is manifested by the individual patient (98). Self-harm behaviour, considered unique to BPD, warrants further understanding within an NP or cognitive framework. No matter how one interprets these findings, one cannot ignore the converging patterns of NP impairment associated with BPD that may represent a cognitive vulnerability for the development of the disorder and the manifestation of suicidal behaviour. A trait-like vulnerability for suicide involving dysregulatory, disinhibiting processes is suggested by the available data but awaits clarification and confirmation.
Note
A detailed list of studies investigating neuropsychology in BPD is available from the author.
Funding and Support
This review was supported by a Canadian Institutes of Health Research fellowship as part of the clinical trial "Hope for the Chronically Suicidal Patient: Evaluating the Clinical and Health Services Impact of Dialectical Behaviour Therapy in Individuals With Borderline Personality Disorder" with the Arthur Sommer Rotenberg Chair in Suicide Studies, St Michael's Hospital, Toronto, Ontario.
Acknowledgements
We acknowledge the contributions of Paul Links, Arthur Sommer Rotenberg Chair in Suicide Studies, and Professor, Dept of Psychiatry, University of Toronto; and Rosemary Tannock, Senior Scientist, Brain and Behaviour Program, The Hospital for Sick Children, and Associate Professor of Psychiatry, University of Toronto.
R�sum� : Les corr�lats neuropsychologiques du trouble de la personnalit� limite et du comportement suicidaire
Objectif : Chez des sujets souffrant du trouble de la personnalit� limite (TPL) compar�s � des sujets ayant tent� de se suicider, examiner la fonction neuropsychologique (NP) qui peut pr�disposer au comportement suicidaire sur un continuum de l�talit� �lev�e et faible.
M�thode : Nous avons effectu� des recherches �lectroniques dans MEDLINE, PsycINFO, EMBASE, Biosos Reviews et Cinhal. Les recherches �taient limit�es aux publications en anglais de 1985 � aujourd'hui. Les termes de recherche trouble de la personnalit� limite, tentative de suicide, neuropsychologique, fonction executive, neurocognitif, et fonction neuropsychologique ont produit 29 �tudes neuropsychologiques incluant le TPL, et 7 �tudes neuropsychologiques de personnes ayant tent� de se suicider, sans �gard au diagnostic psychiatrique.
R�sultats : Sur les �tudes du TPL, 83 % constataient une d�ficience NP dans un ou plusieurs domaines cognitifs, ind�pendamment de la d�pression, faisant appel � des d�ficits sp�cifiques ou g�n�ralis�s li�s aux r�gions pr�frontale dorsolat�rale et orbitofrontale. Les fonctions les plus fr�quemment d�clar�es (dans 71 % � 86 % des �tudes du TPL) sont les processus inhibiteurs de r�ponse affectant le rendement de la fonction executive qui exige une attention acc�l�r�e, la souplesse cognitive, le traitement visuospatial, et le processus d�cisionnel; 60 % � 66 % des �tudes du TPL rapportent une d�ficience de l'attention, une d�ficience verbale et une d�ficience de la m�moire non verbale. Les processus les moins affect�s par le TPL semblent �tre la m�moire de travail spatiale, la planification et possiblement, le QI. Les similitudes des d�ficits NP dans les �tudes du TPL et des tentatives de suicide sont le processus d�cisionnel et les rendements au Trail Making Test (TMT). Les r�sultats de la fluidit� verbale, du test Stroop et du test Wisconsin n�cessitent d'autres comparaisons.
Conclusions : Les fonctions executives partag�es, et les processus d�sinhibiteurs d'�veil qu'elles apportent, ainsi que la fluidit� verbale, les rendements au TMT et possiblement au Stroop associ�s aux r�gions du cortex pr�frontal dorsolat�ral peuvent repr�senter une voie commune vers la tentative de suicide. Une voie inhibitrice motivationnelle pr�dominante impliquant les processus d�cisionnels associ�s aux r�gions orbitofrontales peut influencer l'expression d'actes autodestructeurs ou un comportement suicidaire de faible l�talit�. L'hypoth�se d'une vuln�rabilit� cognitive semblable � un trait pour un comportement suicidaire impliquant des voies dysr�gulatrices, d�sinhibitrices n'est pas confirm�e.
[Reference]
References
1. Andrulonis PA, Vogel NG. Comparison of borderline personality subcategories to schizophrenic and affective disorders. Br J Psychiatry 1984; 144:358-63.
2. van Reekum R. Acquired and developmental brain dysfunction in borderline personality disorder. Can J Psychiatry 1993;38(Suppl 1):S4-S10.
3. Paris J, Zelkowitz P, Guzdcr J, Joseph S, Feldman R. Neuropsychologicai factors associated with borderline pathology in children. J Am Acad Child Adolesc Psychiatry 1999;38:770-4.
4. Irle E, Lange C, Sachsse U. Reduced size and abnormal asymmetry of parietal cortex in women with borderline personality disorder. Biol Psychiatry 2005;57:173-82.
5. Zelkowitz P, Paris J, Guzder J, Feldman R. Diatheses and stressors in borderline pathology of childhood: the role of neuropsychological risk and trauma.[comment]. J Am AcadChildAdolesc Psychiatry 2001;40:100-5.
6. Bradley R, Jenei J, Westen D. Etiology of borderline personality disorder: disentangling the contributions of intercorrelated antecedents. J Nerv Ment Dis 2005;193(1):24-31.
7. Mann JJ, Waternaux C, Haas GL, Malone KM. Toward a clinical model of suicidal behavior in psychiatric patients. Am J Psychiatry 1999;156:181-9.
8. Links PS, Heslegravc RJ, Mitton JE, van RR, Patrick J. Borderline personality disorder and substance abuse: consequences of comorbidity. Can J Psychiatry 1995;40(1):9-14.
9. Boutros NN, Torello M, McGlashan TH. Elcctrophysiological aberrations in borderline personality disorder: state of the evidence. J Neuropsychiatry CHn Neurosci 2003; 15:145-54.
10. Tebartz van EL, Hesslinger B, Thiel T, Geiger E, Haegele K. Lcmieux L, and others. Frontolimbic brain abnormalities in patients with borderline personality disorder: a volumetric magnetic resonance imaging study. Biol Psychiatry 2003;54:163-71.
11. De la Fuente JM, Tugendhaft P, Mavroudakis N. Electroencephalographic abnormalities in borderline personality disorder. Psychiatr Res 1998;77:131-8.
12. Juengling FD, Schmahl C, Hesslinger B, Ebert D, Bremner JD, Gostomzyk J, and others. Positron emission tomography in female patients with borderline personality disorder. J Psychiatr Res 2003;37:109-15.
13. Driessen M, Beblo T, Mertens M, Piefke M, Rullkoetter N, Silva-Saavedra A, and others. Posttraumatic stress disorder and fMRl activation patterns of traumatic memory in patients with borderline personality disorder. Biol Psychiatry 2004:55:603-11.
14. Goyer PF, Andreason PJ, Semple WE, Clayton AH. King AC, Compton-Toth BA, and others. Positron-emission tomography and personality disorders. Neuropsychopharmacology 1994; 10(1):21-8.
15. Meares R, Melkonian D, Gordon E, Williams L. Distinct pattern of P3a event-related potential in borderline personality disorder. Neurorcport 2005;16:289-93.
16. Soloff PH, Meltzer CC, Becker C, Greer PJ, Kelly TM, Constantine D. Impulsivity and prefrontal hypometabolism in borderline personality disorder. Psychiatr Res 2003;123:153-63.
17. Lyoo IK, Han MH, Cho DY. A brain MRI study in subjects with borderline personality disorder. J Affect Disord 1998;50:235-43.
18. Travers C, King R. An investigation of organic factors in the neuropsychological functioning of patients with borderline personality disorder. J Personal Disord 2005;19(1):1-18.
19. Driessen M, Hcrrmann J, Stahl K, Zwaan M, Meier S, Hill, and others. Magnetic resonance imaging volumes of the hippocampus and the amygdala in women with borderline personality disorder and early traumatization. Arch Gen Psychiatry 2000;57:1115-22.
20. Oquendo MA, Galfalvy H, Russo S, ElHs SP, Grunebaum MF, Burke A, and others. Prospective study of clinical predictors of suicidal acts after a major depressive episode in patients with major depressive disorder or bipolar disorder. Am J Psychiatry 2004;161:1433-41.
21. Soloff PH, Lynch KG, Kelly TM, Malone KM, Mann JJ. Characteristics of suicide attempts of patients with major depressive episode and borderline personality disorder: a comparative study. Am J Psychiatry 2000;157:601-8.
22. Brodsky BS, Malone KM, Ellis SP, Dulit RA, Mann JJ. Characteristics of borderline personality disorder associated with suicidal behavior. Am J Psychiatry 1997;154:1715-9.
23. Yen S, Shea MT, Sanislow CA, Grilo CM, Skodol AE, Gunderson JG, and others. Borderline personality disorder criteria associated with prospectively observed suicidal behavior. Am J Psychiatry 2004;161:1296-8.
24. Townsend E, Hawton K, Altman DG, Arensman E, Gunnell D, Hazell P, and others. The efficacy of problem-solving treatments after deliberate self-harm: meta-analysis of randomized controlled trials with respect to depression, hopelessness and improvement in problems. Psychol Med 2001;31:979-88.
25. Joiner TE Jr, Brown JS, Wingate LR. The psychology and neurobiology of suicidal behavior. Annu Rev Psychol 2005;56:287-314.
26. Mann JJ. Neurobiology of suicidal behaviour, Nat Rev Neurosci 2003;4:819-28.
27. Keilp JG, Sackeim HA, Brodsky BS, Oquendo MA, Malone KM, Mann JJ. Neuropsychological dysfunction in depressed suicide attempters. Am J Psychiatry 2001;158:735-41.
28. Bartfai A, Winborg IM, Nordstrom P, Asberg M. Suicidal behavior and cognitive flexibility: design and verbal fluency after attempted suicide. Suicide Life Threat Behav 1990;20:254-66.
29. Ellis TE, Berg RA, Franzen MD. Neuropsychological performance and suicidal behavior in adult psychiatric inpatients. Percept Mot Skills 1992;75:639-47.
30. Becker ES, Strohbach D, Rinck M. A specific attentional bias in suicide attempters. J Nerv Ment Dis 1999;187:730-5.
31. King DA, Conwell Y, Cox C, Henderson RE, Denning DG, Caine ED. A neuropsychological comparison of depressed suicide attempters and nonattempters. J Neuropsychiatry Clin Neurosci 2000;12(1):64-70.
32. Audenaert K, Goethals I, Van LK, Lahorte P, Brans B, Versijpt J, and others. SPECT neuropsychological activation procedure with the Verbal Fluency Test in attempted suicide patients. Nucl Med Commun 2002;23:907-16.
33. Jollant F, Bellivier F, Leboyer M, Astruc B, Torres S, Verdier R, and others. Impaired decision making in suicide attempters. Am J Psychiatry 2005;162:304-10.
34. Darby D, Walsh K. Neuropsychology, a clinical approach. 5th ed. Toronto (ON): Elsevier; 2005.
35. Cornelius JR, Soloff PH, George AWA, Schulz SC, Tarter R, Brenner RP, and others. An evaluation of the significance of selected neuropsychiatric abnormalities in the etiology of borderline personality disorder. J Personal Disord 2005;3(1):19-25.
36. Sprock J, Rader TJ, Kendall JP, Yoder CY. Neuropsychological functioning in patients with borderline personality disorder. J Clinical Psychol 2000;56:1587-600.
37. Kunert HJ, Druecke HW, Sass H, Herpertz SC. Frontal lobe dysfunctions in borderline personality disorder? Neuropsychological findings. J Personal Disord 2003;17:497-509.
38. Besteiro-Gonz�lez JL, Lemos-Gir�ldez S, Mu�iz J. Neuropsychological, psychophysiological, and personality assessment of DSM-IV clusters of personality disorders. European Journal of Psychological Assessment 2004;20:99-105.
39. Burgess JW. Neurocognitive impairment in dramatic personalities: histrionic, narcissistic, borderline, and antisocial disorders. Psychiatr Res 1992;42:283-290.
40. Judd PD, Ruff RM. Neuropsychological dysfunction in borderline personality disorder. J Personal Disord 1993;7:275-84.
41. Swirsky-Sacchetti T, Gorton G, Samuel S, Sobel R, Genetta-Wadley A, Burleigh B. Neuropsychological function in borderline personality disorder. J Clin Psychol 1993;49:385-96.
42. Monarch ES, Saykin AJ, Flashman LA. Neuropsychological impairment in borderline personality disorder. Psychiatr Clin North Am 2004;27(1):67-82.
43. van Reekum R, Conway CA, Gansler D, White R, Bachman DL. Neurobehavioral study of borderline personality disorder. J Psychiatry Neurosci 1993;18:121-9.
44. O'Leary KM, Brouwers P, Gardner DL, Cowdry RW. Neuropsychological testing of patients with borderline personality disorder. Am J Psychiatry 1991;148:106-11.
45. Lenzenweger MF, Clarkin JF, Fertuck EA, Kernberg OF. Executive neurocognitive functioning and neurobehavioral systems indicators in borderline personality disorder: a preliminary study. J Personal Disord 2004;18:421-38.
46. Kurtz JE, Morey ML. Verbal memory dysfunction in depressed outpatients with and without borderline personality disorder. Journal of Psychopathology and Behavioural Assessment 1999;21:141-56.
47. Dougherty DM, Bjork JM, Huckabee HC, Moeller FG, Swann AC. Laboratory measures of aggression and impulsivity in women with borderline personality disorder. Psychiatr Res 1999;85:315-26.
48. Bazanis E, Rogers RD, Dowson JH, Taylor P, Meux C, Staley C, and others. Neurocognitive deficits in decision-making and planning of patients with DSM-III-R borderline personality disorder. Psychol Med 2002;32:1395-405.
49. Dinn WM, Harris CL, Aycicegi A, Greene PB, Kirkley SM, Reilly C. Neurocognitive function in borderline personality disorder. Prog Neuropsychopharmacol Biol Psychiatry 2004;28:329-41.
50. Stein DJ, Hollander E, Cohen L, Frenkel M. Saoud JB, DeCaria, and others. Neuropsychiatrie impairment in impulsive personality disorders. Psychiatr Res 1993;48:257-66.
51. Dowson JH, McLean A, Bazanis E, Toone B, Young S, Robbins TW, and others. Impaired spatial working memory in adults with attention-deficit/hyperactivity disorder: comparisons with performance in adults with borderline personality disorder and in control subjects. Acta Psychiatr Scand 2004;110(l):45-54.
52. Harris CL, Dinn WM, Marcinkiewicz JA. Partial seizure-like symptoms in borderline personality disorder. Epilepsy Behav 2002;3:433-8.
53. Posner MI, Rothbart MK, Vizueta N, Levy KN, Evans DE, Thomas KM, and others. Attentional mechanisms of borderline personality disorder. Proc Natl Acad Sci U S A 2002;99:16366-70.
54. Stevens A, Burkhardt M, Hautzinger M, Schwarz J, Unckel C. Borderline personality disorder: impaired visual perception and working memory. Psychiatr Res 2004;125:257-67.
55. Berlin HA, Rolls ET. Time perception, impulsivity, emotionality, and personality in self-harming borderline personality disorder patients. J Personal Disord 2004;18:358-78.
56. Bergvall AH, Nilsson T, Hansen S. Exploring the link between character, personality disorder, and neuropsychological function. Eur Psychiatry 2003;18:334-44.
57. Coolidge FL, Segal DL, Stewart S, Ellett JAC. Neuropsychological dysfunction in children with borderline personaltity disorder features: a preliminary investigation. J Res Pers 2000;34:554-61.
58. Fossati A, Novella L, Donati D, Donini M, Maffei C. History of childhood attention deficit/hyperactivity disorder symptoms and borderline personality disorder: a controlled study. Compr Psychiatry 2002;43:369-77.
59. O'Leary KM. Borderline personality disorder. Neuropsychological testing results. Psychiatr Clin North Am 2000;23(1):41-60, vi.
60. Carpenter C, Gold J, Fenton W. Neuropsychological testing results in borderline patients, [poster 316], Presented at the 146th Annual Meeting of the American Psychiatric Association; 1993 May 25; San Francisco (CA).
61. Lezak MD. Neuropsychological assessment. 3rd ed. New York (NY): Oxford University Press; 1995.
62. Alexander MP, Stuss DT. Disorders of frontal lobe functioning. Semin Neurol 2000;20:427-37.
63. Skodol AE, Gunderson JG, McGlashan TH, Dyck IR, Stout RL. Bender DS, and others. Functional impairment in patients with schizotypal, borderline, avoidant, or obsessive-compulsive personality disorder. Am J Psychiatry 2002;159:276-83.
64. Nelson HE. The National Adult Reading Test (NART): test manual. Windsor (UK): NFER; 1982.
65. Lysaker PH, Wickett AM, Lancaster RS, Davis LW. Neurocognitive deficits and history of childhood abuse in schizophrenia spectrum disorders: associations with Cluster B personality traits. Schizophr Res 2004;68(1):87-94.
66. Guralnik O, Schmeidler J, Simeon D. Feeling unreal: cognitive processes in depersonalization. AmJ Psychiatry 2000; 157:103-9.
67. Stuss DT, Alexander MP. Executive functions and the frontal lobes: a conceptual view. Psychol Res 2000:63:289-98.
68. Godefroy O. Frontal syndrome and disorders of executive functions. J Neurol 2003;250(1):1-6.
69. Cummings JL. Frontal-subcortical circuits and human behavior. Arch Neurol 1993;50:873-80.
70. Peterson BS, Skudlarksi J, Gatenby C, Zhang H, Anderson A, Gore J. An fMRI study of stroop word-color intererence: evidence for cingulate subregions subserving multiple distributed attentional systems. Biol Psychiatry 1999;45:1237-58.
71. Vuontela V, Steenari MR, Carlson S. Koivisto J, Fjallbcrg M, Aronen ET. Audiospatial and visuospatial working memory in 6-13 year old school children. Learn Mem 2003;10(1):74-81.
72. Zakzanis KK, Leach L, Kaplan E. On the nature and pattern of ncurocognitive function in major depressive disorder. Neuropsychiatry Neuropsychol Bchav Neurol 1998;11:111-9.
73. Dowson J, Bazanis E, Rogers R, Prevost A, Taylor P, Meux C, and others. Impulsivity in patients with borderline personality disorder. Compr Psychiatry 2004;45(1):29-36.
74. Heaton RK. Wisconsin Card Sorting Test. Lutz (FL): Psychological Assessment Resources; 1981.
75. Goldman-Rakic PS. Specification of higher cortical functions. J Head Trauma Rehabil 1993;8:13-23.
76. Golden J. Stroop Colour and Word Test. Chicago (IL): Stocking; 1978.
77. Twamley EW, Hami S, Stein MB. Neuropsychological function in college students with and without posttraumatic stress disorder. Psychiatr Res 2004;126:265-74.
78. Andreasen NC, Flaum M, Swayze V, O'Leary DS, Alligcr R, Cohcn G. and others. Intelligence and brain structure in normal individuals. Am J Psychiatry 1993;150:130-14.
79. Spinella Marcello. Neurobehavioural correlates of impulsivity: evidence of prefrontal involvement. Int J Neurosci 2004;114:95-104.
80. Neuringer C. Rigid thinking in suicidal individuals. J Consult Clin Psychol 1964;28:54-8.
81. Duberstein PR, Conwell Y, Caine ED. Age difference in the personality characteristics of suicide completers and preliminary findings from a psychological autopsy study. Psychiatry 1994;57:213-24.
82. Schotte DE, Clum GA. Problem-solving skills in suicidal psychiatric patients. J Consult Clinl Psychol 1987;55(1):49-54.
83. Pollock LR, Williams JM. Problem-solving in suicide attempters. Psychol Med 2004;34:163-7.
84. Rourke BP, Young GC, Leenaars AA. A childhood learning diability that predisposes those afflicted to adolescent and adult depression and suicide risk. J Learn Disabil 1989;22:181-5.
85. McBride HS, Siegel L. Learning disabilities and adolescent suicide. J Learn Disabil 1997;30:652-9.
86. Pendleton MG, Heaton RK, Lehman R, Hulihan D. Diagnostic utility of the Thurstone word fluency test in neurological evaluations. J Clin Neuropsychol 1982;4:307-17.
87. Miller E. Verbal fluency as a function of a measure of verbal intelligence and in relation to different types of cereral pathology. Br J Clin Psychol 1984;23:53-7.
88. Audenaert K, Peremans K, Goethals I, Otte A, Dierckx R, van Heeringen C. Functional imaging of the suicidal brain. Nucl Med Commun 2005;26:391-3.
89. Harvey PD, Greenberg BR, Serper MR. The Affective Lability Scale: development, reliability and validity. J Clin Psychol 1989:45:786-93.
90. Sonuga-Barke EJ. The dual pathway model of AD/HD: an elaboration of neuro-developmental characteristics. Neurosci Biobehav Rev 2003;27:593-604.
91. Coolidge FL, Thede LL, Jang KL. Are personality disorders psychological manifestations of executive function deficits? Bivariate heritability evidence from a twin study. Behav Genet 2004:34(1 ):75-84.
92. Barkley RA. The executive functions and self-regulation: an evolutionary neuropsychological perspective. Neuropsychol Rev 2001;11(1):1-29.
93. Nigg JT. Neuropsychologic theory and findings in attention-deficit/hyperactivity disorder: the state of the field and salient challenges for the coming decade. Biol Psychiatry 2005;57:1424-35.
94. Sonuga-Barke EJ. Causal models of attention-deficit/hyperactivity disorder: from common simple deficits to multiple developmental pathways. Biol Psychiatry 2005;57:1231-8.
95. Castellanos FX, Tannock R. Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotyes. Nat Rev Neurosci 2002;3:617-27.
96. Gray JA. The neuropsychology of anxiety; an enquiry into the functions of the septo-hippocampal system. New York (NY): Oxford University Press; 1982.
97. Kagan J, Reznick JC, Snidman N. The physiology and psychology of behavioral inhibition in children. Child Dev 1987;58:1459-73.
98. Nigg JT, Willcutt EG, Doyle AE, Sonuga-Barke EJ. Causal heterogeneity in attention-deficit/hyperactivity disorder: do we need neuropsychologically impaired subtypes?. Biol Psychiatry 2005;57:1224-30.
99. Rolls ET. The functions of the orbitofrontal cortex. Brain Cogn 2004;55(1):11-29.
100. Bechara A, Damasio H, Damasio A. Role of the amygdala in decision-making. The New York Academy of Science 2003;985:356-69.
101. Dias R, Robbins TW, Roberts AC. Dissociable forms of inhibitory control within prefrontal cortex with an analog of the Wisconsin Card Sort Test: restriction to novel situations and independence from "on-line" processing. J Neurosci 1997;17:9285-97.
[Author Affiliation]
Jeannette LeGris, BN, MHSc, PhD Candidate1, Rob van Reekum, MD, FRCPC2
[Author Affiliation]
Manuscript received and accepted November 2005.
1 Fellow, The Arthur Sommer Rotenberg Chair in Suicide Studies, St Michael's Hospital, Toronto, Ontario; Assistant Professor, Faculty of Health Sciences, School of Nursing, McMaster University, Hamilton, Ontario.
2 Assistant Professor, Department of Psychiatry, University of Toronto, Toronto, Ontario; Baycrest Centre for Geriatric Care, Toronto Ontario. Address for correspondence: J LeGris, Faculty of Health Sciences, Rm 2Jl 2, McMaster University, 120 Main street West, Hamilton, ON L8N 3Z5 legrisj@smh.toronto.on.ca; legrisj@mcmaster.ca
