Emotionally controlled decision-making and a gene variant related to serotonin synthesis in women with borderline personality disorder

Borderline personality disorder and learning: The influences of emotional state and social versus nonsocial feedback

BACKGROUND

Borderline personality disorder (BPD) has been associated with decision-making deficits, yet such deficits may be context dependent, particularly emotional state and social context. Reinforcement learning models offer an avenue to pinpoint decision-making impairments. The current study used reinforcement learning models to examine whether feedback type (social vs. nonsocial) or emotional state (neutral vs. negative) influence the association between BPD and decision making.

METHOD

Adults (N = 131) with a range of BPD symptoms completed a diagnostic interview and a computerized learning task after neutral and negative emotion inductions. We examined accuracy, learning rate, and exploration.

RESULTS

We conducted linear models to examine the association between BPD criteria, feedback type, and emotional state on learning parameters and learning accuracy. We found that the negative emotion condition was associated with greater exploration, particularly for those with elevated BPD features. Furthermore, elevated BPD features were associated with impaired accuracy when aiming to avoid loss. A 3-way interaction between BPD, emotion, and feedback indicated that, for people with higher BPD features, learning performance was further impaired when receiving social feedback in the negative emotion condition.

LIMITATIONS

Several limitations warrant mention, including a relatively homogenous sample, possible co-occurring diagnoses, and methodological consideration with the learning task.

CONCLUSIONS

The present study underscored the link between BPD and learning impairments. Amplified learning alterations under negative social contexts have important implications for identifying optimal venues to teach new skills (of relevance to treatment) for those with BPD.

The effects of tryptophan loading on Attention Deficit Hyperactivity in adults: A remote double blind randomised controlled trial

BACKGROUND

Despite the impact and prevalence of Attention Deficit Hyperactivity Disorder (ADHD), current treatment options remain limited and there is a drive for alternative approaches, including those building on evidence of a role for tryptophan (TRP) and serotonin (5-HT). This study aimed to evaluate the effect of acute TRP loading on attention and impulsivity in adults with ADHD.

TRIAL DESIGN AND METHODS

We conducted a remote double blind randomised controlled trial (RCT) using TRP loading to examine the effects of a balanced amino acid load in comparison to low and high TRP loading in individuals with ADHD (medicated, N = 48, and unmedicated, N = 46) and controls (N = 50). Participants were randomised into one of three TRP treatment groups using stratified randomisation considering participant group and gender using a 1:1:1 ratio. Baseline testing of attention and impulsivity using the Test of Variables of Attention Task, Delay Discounting Task, and Iowa Gambling Task was followed by consumption of a protein drink (BAL, LOW, or HIGH TRP) before repeated testing.

RESULTS AND CONCLUSIONS

No effects of TRP were observed for any of the measures. In the present study, TRP loading did not impact on any measure of attention or impulsivity in those with ADHD or Controls. The findings need to be confirmed in another trial with a larger number of patients that also considers additional measures of dietary protein, plasma TRP and aggression. (Registration ID ISRCTN15119603).

Cognitive modelling to assess decision-making impairments in patients with current depression and with/without suicide history

It has been reported that decision making is impaired in suicide attempters. Decision making is a complex process and little is known about its different components. Yet, this information would help to understand the functioning of suicidal minds. In this study, the Prospect Valence-Learning (PVL) computational model was applied to the Iowa Gambling Task (IGT) to investigate and compare decision-making components in patients with affective disorder and with/without history of suicide attempts and in healthy controls. To this aim, 116 inpatients with current major depressive episode (among whom 62 suicide attempters) and 38 healthy controls were recruited. Decision-making performance was measured using the IGT. The Bayesian computational PVL model was applied to compare the feedback sensitivity, loss aversion, learning/memory, and choice consistency components of decision making in the different groups. Depressive symptomatology was assessed using the Beck Depression Inventory short form (BDI-SF). The total IGT net score and the loss aversion and learning/memory scores were lower in suicide attempters than in healthy controls. The choice consistency score was low in all patients (with/without suicide history) compared with healthy controls. Moreover, patients with high BDI score showed a positive relationship between the choice consistency score and suicide attempt. These findings suggest that decision-making impairment in depressed patients with and without suicidal history might be the result of underlying problems in feedback processing and task learning, which influence the building of long-term strategies. All these impairments should be targeted in therapeutic strategies for suicidal patients.

The serotonin transporter gene polymorphism (5-HTTLPR) and affective symptoms among women diagnosed with borderline personality disorder

Gene variants of the serotonin transporter have been associated with vulnerability to affective disorders. In particular, the presence of one or two copies of the short (s) allele of the 5-HTTLPR polymorphism has been associated with reduced serotonin transporter expression and function, and vulnerability to affective disorders. To test for an association between variants of the serotonin transporter gene polymorphism (5-HTTLPR) and relevant clinical features of borderline personality disorder (BPD), a psychiatric disorder with symptoms characteristic for serotonin dysfunction, 77 women with BPD were genotyped in the 5-HTTLPR polymorphism. They rated their subjective experience of borderline-specific, depressive, anxious and obsessive-compulsive symptoms, and were interviewed about lifetime incidence of suicide attempts and self-harming acts. Carriers of two s alleles of the 5-HTTLPR reported more symptoms of borderline, depression, anxiety and obsessive-compulsive behaviours, but not of suicidal and self-injury behaviour, compared to carriers of a long (l) allele. This indicates that the 5-HTTLPR ss homozygous genotype might influence serotonin function affecting susceptibility to both borderline-specific, depressive, anxious and obsessive-compulsive symptoms in BPD, and leading to a more severe symptomatology related to these clinical features. Further, this suggests that 5-HTT gene variants may not be as influential on suicidal and self-injury behaviour in BPD.

The Modulating Role of Self-Referential Stimuli and Processes in the Effect of Stress and Negative Emotion on Inhibition Processes in Borderline Personality Disorder: Proposition of a Model to Integrate the Self-Concept and Inhibition Processes

Impulsivity is an important clinical and diagnostic feature of borderline personality disorder (BPD). Even though it has been reported that BPD individuals' inhibition performance is significantly reduced in the context of negative emotion or stress, this literature shows mixed results, raising questions about the possible role played by other factors. Winter (2016) proposed that negative emotion stimuli can be more disruptive for BPD individuals' attention control performance because they induce higher distractibility self-referential processes. This article aimed to systematically review the literature regarding the effect of stress and negative emotions on three main inhibition processes-prepotent response inhibition, resistance to distractor interference, and resistance to proactive interference-in BPD and to verify the putative modulating role of self-referential stimuli and processes on these inhibition processes. All English and French experimental studies published until August 2018 were searched in PsychINFO and PubMED databases. The following keywords were used: "borderline* AND inhibit* OR interference* OR forget* OR task* AND emotion* OR stress* OR affect*". A total of 1215 articles were included in the study. After full text revision, twenty-six papers were selected for review. The results of this review indicate that when stimuli or procedures involve self-reference stimuli or processes, BPD individuals' performance seems to be more disrupted in all three inhibition processes. A model based on Winter's and Kernberg's models is proposed with the aim of integrating the self-concept with inhibition processes in BPD.

An investigation of the effect of trauma script exposure on risk-taking among patients with substance use disorders and posttraumatic stress disorder

Studies show that patients with substance use disorders (SUD) and posttraumatic stress disorder (PTSD) are at high risk for engaging in risky behaviors. However, these studies do not speak to the context in which these behaviors are more likely to occur. This study examined whether SUD patients with current PTSD, compared to those without a history of PTSD, are more likely to exhibit risk-taking on a laboratory-based risk-taking task, the Iowa Gambling Task (IGT), following exposure to a personalized trauma script versus a neutral script. The sample consisted of 122 trauma-exposed SUD patients with and without PTSD. Participants were administered a series of diagnostic interviews and personalized trauma scripts were created. On separate days, participants were exposed to a neutral or trauma script, followed by the IGT. Contrary to expectations, PTSD-SUD patients exhibited significantly greater risk-taking after the neutral (vs. trauma) script than those without PTSD. Moreover, whereas SUD patients without PTSD evidenced stability in IGT performance across scripts, those with PTSD exhibited significantly lower risk-taking on the IGT following the trauma (vs. neutral) script. Results provide support for the context dependent nature of risk-taking in PTSD-SUD patients and suggest they may become more risk averse in the context of trauma-related distress.

The effect of methylphenidate on decision making in patients with borderline personality disorder and attention-deficit/hyperactivity disorder

Impaired decision making in patients with borderline personality disorder (BPD) has been reported in several studies. Although methylphenidate (MPH) is known to ameliorate impaired decision making in patients with attention-deficit/hyperactivity disorder (ADHD), it has not yet been examined in patients with BPD. We therefore assessed the efficacy of a single dose of MPH on cognitive functions and decision making in patients with BPD. Twenty-two patients diagnosed with BPD participated in the study. The study was a randomized, double-blind placebo-controlled, random block order cross-over trial. Patients participated in two sessions and performed the Test of Variables of Attention, a digit-span test, and the computerized Iowa Gambling Task, after they had been administered either the MPH or a placebo. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale-18. Lower scores on the inattention symptoms scale were associated with a greater improvement in decision making following the administration of MPH when compared with improvements in patients with higher ADHD scores [F(1,17)=5.63, P=0.030]. We conclude that MPH may improve decision making in patients with BPD, although this effect is mediated by the level of ADHD symptoms. Further studies are needed to assess whether a prolonged beneficial effect of MPH on decision making in patients with BPD might also be present in 'real life'.

Suicide behavior as a quantitative trait and its genetic background

INTRODUCTION

Studies have not given yet a clear answer what is the genetic background of suicidal predisposition. The associations between polymorphisms of the TPH1 and 5-HTTLPR genes and violent suicidal behavior was revealed with the least inconsistencies.

METHOD

We selected 10 "strong candidate genes" and 35 SNPs, SLC6A4 and ACP1 for replication study. We searched associations between precisely described suicidal phenotype in 825 affective patients and polymorphisms of selected neurobiological pathways genes as well as their interactions that constitute suicidal risk.

RESULTS

The results confirm the role of TPH1, TPH2, 5HT2A, CRHR1 and ACP1 variants in the risk of suicidal behavior.

LIMITATIONS

In our study we analyzed limited number of candidate genes and only one of them is linked to lithium mechanism of action. We had no data on pharmacological treatment of investigated patients and its relation to the time of suicide attempt.

CONCLUSION

Our results indicate that polymorphisms of various signaling pathways are involved in the pathogenesis of suicidal behavior. Non-genetic factors are also involved in the risk of suicidal attempts.

Disadvantageous decision-making in borderline personality disorder: Partial support from a meta-analytic review

To achieve long-term goals, organisms evaluate outcomes and expected consequences of their behaviors. Unfavorable decisions maintain many symptoms of borderline personality disorder (BPD); therefore, a better understanding of the mechanisms underlying decision-making in BPD is needed. In this review, the current literature comparing decision-making in patients with BPD versus healthy controls is analyzed. Twenty-eight empirical studies were identified through a structured literature search. The effect sizes from studies applying comparable experimental tasks were analyzed. It was found that (1) BPD patients discounted delayed rewards more strongly; (2) reversal learning was not significantly altered in BPD; and (3) BPD patients achieved lower net gains in the Iowa Gambling Task (IGT). Current psychotropic medication, sex and differences in age between the patient and control group moderated the IGT outcome. Altered decision-making in a variety of other tasks was supported by a qualitative review. In summary, current evidence supports the altered valuation of outcomes in BPD. A multifaceted influence on decision-making and adaptive learning is reflected in this literature.

Reduced risk avoidance and altered neural correlates of feedback processing in patients with borderline personality disorder

Patients with borderline personality disorder (BPD) show deficits in reward-guided decision making and learning. The present study examined risk-taking behavior in combination with feedback processing. Eighteen BPD patients and 18 healthy controls performed a probabilistic two-choice gambling task, while an electroencephalogram was recorded. Options differed in risk, but were identical in expected value and outcome probability. The feedback-related negativity (FRN) and the feedback-related P300 were analyzed. Healthy controls preferred low-risk over high-risk options, whereas BPD patients chose both option with equal probability. FRN amplitudes were reduced in BPD, but effects of feedback valence and risk did not differ between groups. This suggests attenuated outcome processing in the anterior cingulate cortex, but intact reward prediction error signaling. Furthermore, the modulation of the feedback-related P300 with feedback valence and risk was smaller in BPD patients, and decreased P300 amplitudes were associated with increased behavioral risk-taking behavior. These findings could relate to the reduced ability of BPD patients to learn and adequately adjust their behavior based on feedback information, possibly due to reduced significance of negative feedback.

A negative relationship between ventral striatal loss anticipation response and impulsivity in borderline personality disorder

Patients with borderline personality disorder (BPD) frequently exhibit impulsive behavior, and self-reported impulsivity is typically higher in BPD patients when compared to healthy controls. Previous functional neuroimaging studies have suggested a link between impulsivity, the ventral striatal response to reward anticipation, and prediction errors. Here we investigated the striatal neural response to monetary gain and loss anticipation and their relationship with impulsivity in 21 female BPD patients and 23 age-matched female healthy controls using functional magnetic resonance imaging (fMRI). Participants performed a delayed monetary incentive task in which three categories of objects predicted a potential gain, loss, or neutral outcome. Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11). Compared to healthy controls, BPD patients exhibited significantly reduced fMRI responses of the ventral striatum/nucleus accumbens (VS/NAcc) to both reward-predicting and loss-predicting cues. BIS-11 scores showed a significant positive correlation with the VS/NAcc reward anticipation responses in healthy controls, and this correlation, while also nominally positive, failed to reach significance in BPD patients. BPD patients, on the other hand, exhibited a significantly negative correlation between ventral striatal loss anticipation responses and BIS-11 scores, whereas this correlation was significantly positive in healthy controls. Our results suggest that patients with BPD show attenuated anticipation responses in the VS/NAcc and, furthermore, that higher impulsivity in BPD patients might be related to impaired prediction of aversive outcomes.

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We investigated striatal reward and loss anticipation in patients with Borderline Personality Disorder (BPD) and controls

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BPD patients relative to controls exhibited reduced ventral striatal / nucleus accumbens (VS/NAcc) anticipation responses

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In healthy controls, VS responses to gains and losses correlated positively with impulsivity

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BPD patients exhibited a negative correlation between loss responses and impulsivity.

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Our results suggest that impulsivity in BPD patients may in part result from impaired anticipation of aversive outcomes.

Insensitivity to the Magnitude of Potential Gains or Losses When Making Risky Choices: Women With Borderline Personality Disorder Compared With Bipolar Disorder and Controls

Poor decision-making is a feature of borderline personality disorder (BPD) and bipolar disorder (BD). Twenty women with BPD, 20 women with BD, and 20 healthy females completed a risky choice task. Those with BPD exhibited altered processing of information about potential gains and losses, with a bias toward large compared to small gains, large compared to small losses, and a tendency to choose outcomes with a negative expected value. This failure to use explicit reinforcement signals was not observed in those with BD. Difficulties using reward information to make decisions may impair day-to-day function. Such impairments offer new treatment targets in BPD.

Impact of stress on different components of impulsivity in borderline personality disorder

BACKGROUND

Previous research on impulsivity in borderline personality disorder (BPD) has revealed inconsistent findings. Impulsive behaviour is often observed during states of emotional distress and might be exaggerated by current attention deficit hyperactivity disorder (ADHD) symptoms in individuals with BPD. We aimed to investigate different components of impulsivity dependent on stress induction controlling for self-reported ADHD symptoms in BPD. METHOD. A total of 31 unmedicated women with BPD and 30 healthy women (healthy controls; HCs), matched for age, education and intelligence, completed self-reports and behavioural tasks measuring response inhibition (go/stop task) and feedback-driven decision making (Iowa Gambling Task) under resting conditions and after experimental stress induction. ADHD symptoms were included as a covariate in the analyses of behavioural impulsivity. Additionally, self-reported emotion-regulation capacities were assessed.

RESULTS

BPD patients reported higher impulsive traits than HCs. During stress conditions - compared with resting conditions - self-reported impulsivity was elevated in both groups. Patients with BPD reported higher state impulsivity under both conditions and a significantly stronger stress-dependent increase in state impulsivity. On the behavioural level, BPD patients showed significantly impaired performance on the go/stop task under stress conditions, even when considering ADHD symptoms as a covariate, but not under resting conditions. No group differences on the Iowa Gambling Task were observed. Correlations between impulsivity measures and emotion-regulation capacities were observed in BPD patients.

CONCLUSIONS

Findings suggest a significant impact of stress on self-perceived state impulsivity and on response disinhibition (even when considering current ADHD symptoms) in females with BPD.

Suboptimal Decision Making in Borderline Personality Disorder: Effect of Potential Losses

This research explored the underlying processes mediating risky decisions for individuals with Borderline Personality Disorder (BPD). We tested whether BPD patients were more apt to take risks compared to a matched comparison group. We used two controlled tasks designed to assess risky decision-making, both to achieve gains and to avoid losses. Overall, BPD patients showed increased risk-taking compared to the comparison group (p = .011, η2 = .224), and were especially likely to be risk-seeking when the decision was framed as a potential loss (p < .0001, d = 1.77). When the outcome involved pure losses, BPD patients were insensitive to the relative expected value between choice options resulting in suboptimal decision making (p = .004, d = 1.24), but did not differ from the comparison group when taking risks to achieve gains (p = .603, d = 0.21). We discuss these results in the context of behavioral and neuropsychiatric research suggesting abnormalities BPD patients’ ability to effectively regulate affect.

Genetics of borderline personality disorder: systematic review and proposal of an integrative model

Borderline personality disorder (BPD) is one of the most common mental disorders and is characterized by a pervasive pattern of emotional lability, impulsivity, interpersonal difficulties, identity disturbances, and disturbed cognition. Here, we performed a systematic review of the literature concerning the genetics of BPD, including familial and twin studies, association studies, and gene-environment interaction studies. Moreover, meta-analyses were performed when at least two case-control studies testing the same polymorphism were available. For each gene variant, a pooled odds ratio (OR) was calculated using fixed or random effects models. Familial and twin studies largely support the potential role of a genetic vulnerability at the root of BPD, with an estimated heritability of approximately 40%. Moreover, there is evidence for both gene-environment interactions and correlations. However, association studies for BPD are sparse, making it difficult to draw clear conclusions. According to our meta-analysis, no significant associations were found for the serotonin transporter gene, the tryptophan hydroxylase 1 gene, or the serotonin 1B receptor gene. We hypothesize that such a discrepancy (negative association studies but high heritability of the disorder) could be understandable through a paradigm shift, in which "plasticity" genes (rather than "vulnerability" genes) would be involved. Such a framework postulates a balance between positive and negative events, which interact with plasticity genes in the genesis of BPD.

Genetic modulation of borderline personality disorder: systematic review and meta-analysis

Borderline personality disorder (BPD) is a highly prevalent psychiatric disorder with high morbidity and mortality. Early theories ascribed an environmental etiology of BPD, but growing evidence supports a genetic vulnerability as well. The primary aim of this study was to systematically review genetic association studies focused on BPD. PubMed, ISI Web of Knowledge and PsycINFO databases were searched for studies published until December 2012. Meta-analyses were also performed when three or more studies reported genetic data on the same polymorphism. Data were analyzed with Cochrane Collaboration Review Manager Software (RevMan, version 5.0). Quality and publication bias were assessed. The systematic review of association studies examining genetic polymorphisms and BPD produced conflicting results. Meta-analyses were performed for three serotonergic polymorphisms: two common polymorphisms of the serotonin transporter gene (SLC6A4), the promoter insertion/deletion (5-HTTLPR) and the intron 2 VNTR (STin2 VNTR), and the rs1800532 (A218C) polymorphism of the tryptophan hydroxylase 1 gene (TPH1), all showing no association. No direct role of genetic polymorphisms was found in BPD. However, a few studies only are present in literature to draw definite conclusions. Further studies focusing on gene × gene and gene × environment interactions are needed to more deeply dissect the genetic role in the modulation of BPD.

Impulsivity in borderline personality disorder: a matter of disturbed impulse control or a facet of emotional dysregulation?

Impulsivity is regarded as a clinical, diagnostic and pathophysiological hallmark of borderline personality disorder (BPD). Self-report measures of impulsivity consistently support the notion of higher impulsive traits in BPD patients as compared to healthy control subjects. Laboratory tests of impulsivity, i.e. neuropsychological tests of impulse control render weak and inconsistent results both across different cognitive components of impulse control and within the same cognitive component of impulse control. One important factor worsening impulsive behaviors and impulse control deficits in BPD is comorbid attention-deficit/hyperactivity disorder (ADHD). In addition, emotional dysregulation interacts with impulse control especially for BPD salient emotions. In sum, although basic mechanisms of impulse control seem not to be disturbed in BPD, clinically well observed impulsive behaviors may be explained by comorbid ADHD or may be the consequence of dysregulation of BPD salient emotions.

Risky decision-making in borderline personality disorder

Impulsivity is a core feature of borderline personality disorder (BPD). Thereby, individuals with BPD are most often explicitly aware of the deleterious long-term consequences of their impulsive behaviors, but still engage in them. Therefore, the aim of the present study was to test decision-making in BPD. Female individuals with BPD (n=21) and female controls without BPD (CG; n=29) were compared on the Game of Dice Task (GDT) with regard to disadvantageous decision-making and feedback processing. In the GDT rules for reinforcement and punishment are explicitly clear and the outcome is defined by probabilities. By providing feedback about the outcome of previous decisions, the GDT is a valid measure to simulate decision-making in real life situations. Main results revealed that women with BPD make risky decisions significantly more often than the CG. Moreover, they show reduced capacities to advantageously utilize feedback. As deficits in decision-making were correlated with BPD symptom severity and impulsivity, risky decision-making may be a relevant maintenance factor for the disorder.

Rodent versions of the iowa gambling task: opportunities and challenges for the understanding of decision-making

Impaired decision-making is a core problem in several psychiatric disorders including attention-deficit/hyperactivity disorder, schizophrenia, obsessive–compulsive disorder, mania, drug addiction, eating disorders, and substance abuse as well as in chronic pain. To ensure progress in the understanding of the neuropathophysiology of these disorders, animal models with good construct and predictive validity are indispensable. Many human studies aimed at measuring decision-making capacities use the Iowa gambling task (IGT), a task designed to model everyday life choices through a conflict between immediate gratification and long-term outcomes. Recently, new rodent models based on the same principle have been developed to investigate the neurobiological mechanisms underlying IGT-like decision-making on behavioral, neural, and pharmacological levels. The comparative strengths, as well as the similarities and differences between these paradigms are discussed. The contribution of these models to elucidate the neurobehavioral factors that lead to poor decision-making and to the development of better treatments for psychiatric illness is considered, along with important future directions and potential limitations.

Impaired decision making and feedback evaluation in borderline personality disorder

BACKGROUND

Increased impulsivity is considered to be a core characteristic of borderline personality disorder (BPD) and has been shown to play a significant role in decision making and planning. Neuropsychological studies in BPD revealed impairments of executive functions, and it is assumed that these deficits are related to altered feedback processing. However, research on executive functions in BPD is still limited and the underlying deficits remain an open question. The present study, therefore, explored whether decision-making deficits are related to altered feedback evaluation in BPD.

METHOD

A total of 18 BPD patients and 18 matched healthy controls underwent a modified version of the Iowa Gambling Task while an electroencephalogram was recorded. Feedback processing was examined by measuring the feedback-related negativity (FRN) and the P300 as electrophysiological correlates of feedback evaluation.

RESULTS

Behavioural results revealed that BPD patients, relative to controls, made more risky choices and did not improve their performance. With regard to the FRN, amplitudes in BPD patients did not discriminate between positive and negative feedback information. Further, BPD patients showed reduced FRN amplitudes, which were associated with enhanced impulsivity and enhanced risk taking. In contrast, the P300 amplitudes following negative feedback were increased in BPD patients, relative to controls.

CONCLUSIONS

This study indicates that BPD patients are impaired in decision making, which might be related to a dysfunctional use of feedback information. Specifically, BPD patients did not learn to avoid disadvantageous selections, even though they attended to negative consequences.

Serotonin Transporter (5-HTTLPR) Genotype and Childhood Trauma are Associated with Individual Differences in Decision Making

The factors that influence individual differences in decision making are not yet fully characterized, but convergent evidence is accumulating that implicates serotonin (5-HT) system function. Therefore, both genes and environments that influence serotonin function are good candidates for association with risky decision making. In the present study we examined associations between common polymorphisms in the serotonin transporter gene (SLC6A4; 5-HTTLPR and rs25531), the experience of childhood trauma and decision making on the Iowa gambling task (IGT) in 391 (64.5% female) healthy Caucasian adults. Homozygosity for the 5-HTTLPR L allele was associated with riskier decision making in the first block of 20 trials (i.e., decision making under ambiguity, p = 0.004). In addition, mean IGT performance was significantly worse in blocks 3–5 (i.e., decision making under risk, p ≤ 0.05) for those participants who reported experiencing higher levels of childhood trauma. Our findings add to the growing evidence that genetic variation in the 5-HT system is associated with individual differences in decision making under ambiguity; and we report that the experience of childhood trauma is associated with relatively poor decision making under risk.

Genes, suicide and decisions

OBJECTIVE

A better understanding of the pathophysiology of suicidal behaviour (SB) may enable the discovery of more specific treatments and a better identification of vulnerable patients. The vulnerability to SB appears to be underlied by genetic factors coding for traits rendering the individual less able to cope with stressing situations, and more likely to be engaged in a suicidal process.

METHOD

During the recent years, neuroscientific studies begun to identify potential endophenotypes.

RESULTS

We have shown that disadvantageous decision making (DM) was involved in the vulnerability to SB. DM impairment appears to be independent of comorbid psychiatric disorders, associated with emotional dysregulation (i.e. affective lability trait and skin conductance responses), and modulated by serotonergic genotypes associated with SB. In recent fMRI studies, the region that is likely involved in DM, is overactivited in response to angry faces, suggesting a higher sensitivity to specific negative social stimuli. Deficit in risk evaluation and excessive response to specific emotional stimuli may represent key processes in the vulnerability to SB.

CONCLUSIONS

These potential endophenotypes may represent future relevant markers of vulnerability for the identification of vulnerable patients, and relevant targets for the development of new treatments.

Interaction between serotonin transporter promoter and dopamine receptor D4 polymorphisms on decision making

Appropriate decision making is an important brain function to maintain our lives. The Iowa gambling task (IGT) is a tool for decision making under ambiguity. The aims of this study were to evaluate the influence of serotonin transporter linked polymorphic region (5-HTTLPR) and dopamine receptor D4 (DRD4) polymorphisms and their interaction on IGT performance. One hundred fifty-nine normal subjects were involved in this study. All subjects performed the IGT and were genotyped for the triallelic 5-HTTLPR and DRD4 48 bp uVNTR polymorphisms. After controlling for gender, age, and impulsiveness, there were no main effects of 5-HTTLPR and DRD4 gene polymorphisms on total IGT score. However, there was a significant effect on the interaction between 5-HTTLPR and DRD4 on total IGT score. In the presence of the 5-HTTLPR S'S' (SS+SL(G)+L(G)L(G)), subjects with the DRD4 2R+ (2 repeat carrier) had higher total IGT score compared to those with the DRD4 2R-. In contrast, in the absence of the 5-HTTLPR S'S', subjects with the DRD4 2R- had higher total IGT score than those with the DRD4 2R+. When we divided IGT scores into the first and second half of trials, the 5-HTTLPRxDRD4 interaction effects were stronger in the second half block (decision under risk) than in the first half block (decision under ambiguity). In conclusion, the DRD4 genotypes might influence decision-making performance differently according to the background genotypes of 5-HTTLPR.

Serotonergic and dopaminergic modulation of gambling behavior as assessed using a novel rat gambling task

Pathological gambling (PG) is characterized by persistent, maladaptive gambling behavior, which disrupts personal and professional life. Animal models of gambling behavior could make a significant contribution to improving our understanding of the neural and neurochemical basis of gambling, and the treatment of PG. When gambling, failing to win critically results in the loss of resources wagered as well as the absence of additional gain. Here, we have incorporated these concepts into a novel rat gambling task (rGT), based, in part, on the 'Iowa' gambling task (IGT) commonly used clinically to measure gambling-like behavior. Rats choose among four different options to earn as many sugar pellets as possible within 30 min. Each option is associated with the delivery of a different amount of reward, but also with a different probability and duration of punishing time-out periods during which reward cannot be earned. The schedules are designed such that persistent choice of options linked with larger rewards result in fewer pellets earned per unit time. Rats learn to avoid these risky options to maximize their earnings, comparable with the optimal strategy in the IGT. Both d-amphetamine and the 5-HT(1A) receptor agonist, 8-OH-DPAT, impaired task performance. In contrast, the dopamine D(2) receptor antagonist, eticlopride, improved performance, whereas the D(1) receptor antagonist, SCH23390, had no effect. These data suggest that both serotonergic and dopaminergic agents can impair and improve gambling performance, and indicate that the rGT will be a useful tool to study the biological basis of gambling.

Social problem solving, autobiographical memory, trauma, and depression in women with borderline personality disorder and a history of suicide attempts

OBJECTIVES

The primary aim of this study was to compare the retrieval of autobiographical memory and the social problem-solving performance of individuals with borderline personality disorder (BPD) and a history of suicide attempts, with and without concurrent diagnoses of depression and/or post-traumatic stress disorder (PTSD), to that of controls. Additionally, the relationships between autobiographical memory, social problem-solving skills, and various clinical characteristics were examined in the BPD group.

DESIGN

Individuals with BPD who had made at least two suicide attempts were compared to controls with regard to specificity of autobiographical memory and social problem-solving skills. Autobiographical memory specificity and social problem-solving skills were further studied in the BPD group by comparing depressed participants to non-depressed participants; and autobiographical memory specificity was also studied by comparing participants with and without PTSD.

METHOD

A total of 47 women with a diagnosis of BPD and 30 controls completed the Autobiographical Memory Test, assessing memory specificity, and the means-end problem solving-procedure, measuring social problem-solving skills. The prevalence of suicidal/self-injurious behaviour, and the exposure to violence, was also assessed in the BPD group.

RESULTS

Compared to controls, participants with BPD showed reduced specificity of autobiographical memory, irrespective of either concurrent depression, previous depression, or concurrent PTSD. The depressed BPD group displayed poor problem-solving skills. Further, an association between unspecific memory and poor problem-solving was displayed in the BPD group.

CONCLUSION

Our results confirmed that reduced specificity of autobiographical memory is an important characteristic of BPD individuals with a history of suicide attempt, independent of depression, or PTSD. Reduced specificity of autobiographical memory was further related to poor social problem-solving capacity in the BPD group.

Genetic contributions of the serotonin transporter to social learning of fear and economic decision making

Serotonin (5-HT) modulates emotional and cognitive functions such as fear conditioning (FC) and decision making. This study investigated the effects of a functional polymorphism in the regulatory region (5-HTTLPR) of the human 5-HT transporter (5-HTT) gene on observational FC, risk taking and susceptibility to framing in decision making under uncertainty, as well as multidimensional anxiety and autonomic control of the heart in healthy volunteers. The present results indicate that in comparison to the homozygotes for the long (l) version of 5-HTTLPR, the carriers of the short (s) version display enhanced observational FC, reduced financial risk taking and increased susceptibility to framing in economic decision making. We also found that s-carriers have increased trait anxiety due to threat in social evaluation, and ambiguous threat perception. In addition, s-carriers also show reduced autonomic control over the heart, and a pattern of reduced vagal tone and increased sympathetic activity in comparison to l-homozygotes. This is the first genetic study that identifies the association of a functional polymorphism in a key neurotransmitter-related gene with complex social-emotional and cognitive processes. The present set of results suggests an endophenotype of anxiety disorders, characterized by enhanced social learning of fear, impaired decision making and dysfunctional autonomic activity.