Monoamine oxidase A gene is associated with borderline personality disorder

Integrating Psychosocial Risks With Emerging Evidence for Borderline Personality Disorders in Adolescence: An Update for Clinicians

Borderline personality disorder (BPD) has seen significant advances in the knowledge of its developmental phenomenology during late childhood and adolescence. Various genetic, neurobiological, psychological, and social factors are implicated in the etiology of BPD. With emerging evidence on BPD development in adolescence, the review focused on recent literature to understand the role of psychosocial risk factors. The effects of adverse familial environment, physical, emotional, verbal, and sexual abuse, intergenerational transmission of psychopathological traits, maternal neglect and rejection, low socioeconomic status, bullying victimization, and dating violence were reviewed to understand their role in the development of BPD. BPD is a highly complex, serious, and enduring mental illness that has now been widely accepted to have symptoms that onset in early adolescence and could be diagnosed as early as age 12. BPD symptoms are stable, phenomenologically distinct from externalizing and internalizing disorders, and often present with co-occurring disorders, which during assessment could not explain impairments associated with BPD. New measures like the Difficulties in Emotion Regulation Scale (DERS), detailed developmental histories, understanding of psychosocial risks, shared decision-making, and psychoeducation could assist in early diagnosis and improvement of long-term outcomes. The implementation of evidence-based treatments is a challenge given higher costs and access to services; therefore, modifications in the treatment based on the core principles of these strategies should be considered. It is imperative to screen for psychosocial factors early in higher-risk groups. The assessment of familial factors, parental histories of psychopathologies, and histories of childhood abuse is important in context with impairing symptoms of clinical presentation and dimensional aspects of self-functioning. The role of family therapies, parental psychoeducation, and the integration of trauma-informed care approaches are important for clinical outcomes. Also, coordinated efforts with multiple stakeholders like school awareness programs, anti-bullying policies, legislation, and enforcement of existing laws might be instrumental in addressing issues related to victimization by peers.

Physical exercise in attention deficit hyperactivity disorder - evidence and implications for the treatment of borderline personality disorder

A growing body of literature indicates a potential role for physical exercise in the treatment of attention deficit hyperactivity disorder (ADHD). Suggested effects include the reduction of ADHD core symptoms as well as improvements in executive functions. In the current review, we provide a short overview on the neurophysiological mechanisms assumed to underlie the beneficial effects of exercise. Further, we review the current evidence from experimental studies regarding both acute exercise and long-term interventions in ADHD. While the positive effects observed after acute aerobic exercise are promising, very few well-designed long-term intervention studies have been conducted yet. Moreover, although exercise effects have not yet been studied in borderline personality disorder (BPD), in the end of this paper we derive hypotheses why exercise could also be beneficial for this patient population.

Interacting Effect of Catechol-O-Methyltransferase (COMT) and Monoamine Oxidase A (MAOA) Gene Polymorphisms, and Stressful Life Events on Aggressive Behavior in Chinese Male Adolescents

Numerous studies have demonstrated that both catechol-O-methyltransferase (COMT) gene and monoamine oxidase A (MAOA) gene have been involved in aggressive behavior, as have stressful life events (SLEs). However, most of available evidence was based upon single gene or single gene–environment design, which is limited in accounting for the variance of aggressive behavior, a complex phenotype. This study examined the possible gene × gene × environment interactions between SLE (interpersonal problems and academic pressure) and two genetic polymorphisms (MAOA T941G and COMT Ala22/72Ser) correlated with aggressive behaviors in a sample of 658 Chinese male adolescents. Mothers and teachers reported on adolescents’ aggressive behavior using Achenbach’s Child Behavior Checklist and Teacher Report Form, respectively. Adolescents completed Self-Rating Life Events Checklist. Saliva samples were collected for DNA analysis. The results revealed no main effects of MAOA T941G and COMT Ala22/72Ser polymorphisms on male adolescents’ aggressive behaviors. However, a two-way interactive effect of interpersonal problems and MAOA T941G genotype on teacher-reported aggressive behavior was observed: adolescents with lower activity of MAOA T allele, but not those with MAOA G allele, exhibited greater aggressive behavior with an increase in interpersonal problems. A three-way interaction among COMT Ala22/72Ser and MAOA T941G polymorphisms, and SLE in the academic pressure on aggressive behavior was also identified. Among adolescents with lower activity of COMT GT/TT genotype and MAOA T allele, the higher level of academic pressure was significantly linked with an amplification of aggressive behavior, whereas this association didn’t exist among those with other genotypes. The present study presents the first evidence of COMT × MAOA × SLE interaction effect on male adolescents’ aggressive behavior, highlights the importance of considering distinct domains of stressful events and information bias when examining the effect of MAOA and COMT on aggressive behavior, and thereby contributes to MAOA gene-aggression and COMT gene-aggression literature.

Past, present, and future of genetic research in borderline personality disorder

Borderline Personality Disorder (BPD) is a major mental illness with a lifetime prevalence of approximately 1-3%, characterized by a persistent pattern of instability in relationships, mood, impulse regulation, and sense of self. This results in impulsive self-damaging behavior, high suicide rates, and severe functional impairment. BPD has a complex, multifactorial etiology, resulting from an interaction among genetic and environmental substrates, and has moderate to high heritability based on twin and family studies. However, our understanding of the genetic architecture of BPD is very limited. This is a critical obstacle since genetics can pave the way for identifying new treatment targets and developing preventive and disease-modifying pharmacological treatments which are currently lacking. We review genetic studies in BPD, with a focus on limitations and challenges and future directions. Genetic research in BPD is still in its very early stages compared to other major psychiatric disorders. Most early genetic studies in BPD were non-replicated association studies in small samples, focused on single candidate genes. More recently, there has been one genome-wide linkage study and a genome-wide association study (GWAS) of subclinical BPD traits and a first GWAS in a relatively modest sample of patients fulfilling full diagnostic criteria for the disorder. Although there are adequate animal models for some of the core dimensions of BPD, there is a lack of translational research including data from animal models in BPD. Research in more pioneering fields, such as imaging genetics, deep sequencing and epigenetics, holds promise for elucidating the pathophysiology of BPD and identifying new treatment targets.

Monoamine Oxidase-A Genetic Variants and Childhood Abuse Predict Impulsiveness in Borderline Personality Disorder

Objective

Impulsivity is a core feature of borderline personality disorder (BPD) and antisocial personality disorder (ASPD) that likely arises from combined genetic and environmental influences. The interaction of the low activity variant of the monoamine oxidase-A (MAOA-L) gene and early childhood adversity has been shown to predict aggression in clinical and non-clinical populations. Although impulsivity is a risk factor for aggression in BPD and ASPD, little research has investigated potential gene-environment (G×E) influences impacting its expression in these conditions. Moreover, G×E interactions may differ by diagnosis.

Methods

Full factorial analysis of variance was employed to investigate the influence of monoamine oxidase-A (MAO-A) genotype, childhood abuse, and diagnosis on Barratt Impulsiveness Scale-11 (BIS-11) scores in 61 individuals: 20 subjects with BPD, 18 subjects with ASPD, and 23 healthy controls.

Results

A group×genotype×abuse interaction was present (F(2,49)=4.4, p=0.018), such that the interaction of MAOA-L and childhood abuse predicted greater BIS-11 motor impulsiveness in BPD. Additionally, BPD subjects reported higher BIS-11 attentional impulsiveness versus ASPD participants (t(1,36)=2.3, p=0.025).

Conclusion

These preliminary results suggest that MAOA-L may modulate the impact of childhood abuse on impulsivity in BPD. Results additionally indicate that impulsiveness may be expressed differently in BPD and ASPD.

Borderline personality disorder and childhood trauma: exploring the affected biological systems and mechanisms

BACKGROUND

According to several studies, the onset of the Borderline Personality Disorder (BPD) depends on the combination between genetic and environmental factors (GxE), in particular between biological vulnerabilities and the exposure to traumatic experiences during childhood. We have searched for studies reporting possible alterations in several biological processes and brain morphological features in relation to childhood trauma experiences and to BPD. We have also looked for epigenetic mechanisms as they could be mediators of the effects of childhood trauma in BPD vulnerability.

DISCUSSION

We prove the role of alterations in Hypothalamic-Pituitary-Adrenal (HPA) axis, in neurotrasmission, in the endogenous opioid system and in neuroplasticity in the childhood trauma-associated vulnerability to develop BPD; we also confirm the presence of morphological changes in several BPD brain areas and in particular in those involved in stress response. Not so many studies are available on epigenetic changes in BPD patients, although these mechanisms are widely investigated in relation to stress-related disorders. A better comprehension of the biological and epigenetic mechanisms, affected by childhood trauma and altered in BPD patients, could allow to identify "at high risk" subjects and to prevent or minimize the development of the disease later in life.

Monoamine Oxidase A in Antisocial Personality Disorder and Borderline Personality Disorder

Purpose of Review

Variation in the monoamine oxidase A (MAO-A) gene and MAO-A enzyme levels have been linked to antisocial behavior and aggression in clinical and non-clinical populations. Here, we provide an overview of the genetic, epigenetic, and neuroimaging research that has examined MAO-A structure and function in antisocial personality disorder (ASPD) and borderline personality disorder (BPD).

Recent Findings

The low-activity MAO-A variable nucleotide tandem repeat genetic polymorphism has shown a robust association with large samples of violent and seriously violent offenders, many of whom had ASPD. A recent positron emission tomography (PET) study of ASPD similarly revealed low MAO-A density in brain regions thought to contribute to the psychopathology of the condition. By contrast, PET has also demonstrated that brain MAO-A levels are increased in BPD and that they relate to symptoms of low mood and suicidality.

Summary

Candidate gene studies have produced the most compelling evidence connecting MAO-A genetic variants to both ASPD and BPD. Still, conflicting results abound in the literature, making it highly unlikely that ASPD or BPD is related to a specific MAO-A genetic variant. Future research should strive to examine how MAO-A genotypes interact with broad-spectrum environmental influences to produce brain endophenotypes that may ultimately become tractable targets for novel treatment strategies.

Transcriptome analysis of genes and gene networks involved in aggressive behavior in mouse and zebrafish

Despite moderate heritability estimates, the molecular architecture of aggressive behavior remains poorly characterized. This study compared gene expression profiles from a genetic mouse model of aggression with zebrafish, an animal model traditionally used to study aggression. A meta-analytic, cross-species approach was used to identify genomic variants associated with aggressive behavior. The Rankprod algorithm was used to evaluated mRNA differences from prefrontal cortex tissues of three sets of mouse lines (N = 18) selectively bred for low and high aggressive behavior (SAL/LAL, TA/TNA, and NC900/NC100). The same approach was used to evaluate mRNA differences in zebrafish (N = 12) exposed to aggressive or non-aggressive social encounters. Results were compared to uncover genes consistently implicated in aggression across both studies. Seventy-six genes were differentially expressed (PFP < 0.05) in aggressive compared to non-aggressive mice. Seventy genes were differentially expressed in zebrafish exposed to a fight encounter compared to isolated zebrafish. Seven genes (Fos, Dusp1, Hdac4, Ier2, Bdnf, Btg2, and Nr4a1) were differentially expressed across both species 5 of which belonging to a gene-network centred on the c-Fos gene hub. Network analysis revealed an association with the MAPK signaling cascade. In human studies HDAC4 haploinsufficiency is a key genetic mechanism associated with brachydactyly mental retardation syndrome (BDMR), which is associated with aggressive behaviors. Moreover, the HDAC4 receptor is a drug target for valproic acid, which is being employed as an effective pharmacological treatment for aggressive behavior in geriatric, psychiatric, and brain-injury patients. © 2016 Wiley Periodicals, Inc.

Genetic and Neuroimaging Features of Personality Disorders: State of the Art

Personality disorders often act as a common denominator for many psychiatric problems, and studies on personality disorders contribute to the etiopathology, diagnosis, and treatment of many mental disorders. In recent years, increasing evidence from various studies has shown distinctive features of personality disorders, and that from genetic and neuroimaging studies has been especially valuable. Genetic studies primarily target the genes encoding neurotransmitters and enzymes in the serotoninergic and dopaminergic systems, and neuroimaging studies mainly focus on the frontal and temporal lobes as well as the limbic-paralimbic system in patients with personality disorders. Although some studies have suffered due to unclear diagnoses of personality disorders and some have included few patients for a given personality disorder, great opportunities remain for investigators to launch new ideas and technologies in the field.

Practitioner Review: Borderline personality disorder in adolescence--recent conceptualization, intervention, and implications for clinical practice

BACKGROUND

The past decade has seen an unprecedented increase in research activity on personality disorders (PDs) in adolescents. The increase in research activity, in addition to major nosological systems legitimizing the diagnosis of borderline personality disorder (BPD) in adolescents, highlights the need to communicate new research on adolescent personality problems to practitioners.

SCOPE

In this review, we provide up-to-date information on the phenomenology, prevalence, associated clinical problems, etiology, and intervention for BPD in adolescents. Our aim was to provide a clinically useful practitioner review and to dispel long-held myths about the validity, diagnostic utility, and treatability of PDs in adolescents.

FINDINGS AND CONCLUSION

Alongside providing up-to-date information on the phenomenology, prevalence, and etiology, we also report on associated clinical problems and interventions for adolescent BPD. It is only through early active assessment and identification of youngsters with these problems that a lifetime of personal suffering and health system burden can be reduced or altogether avoided. A variety of evidence-based approaches are now available to treat BPD and related clinical problems in young people. Future research should focus on establishing optimal precision in the diagnostic processes in different treatment settings.

Recent advances in the developmental aspects of borderline personality disorder

The aim of the current paper was to review the most recent advances in the developmental aspects of borderline personality disorder (BPD) over the last 3 years to highlight the most significant trends in the field. In so doing, we identify and discuss two exciting new trends: (a) an emphasis on the biological basis of adolescent BPD and (b) empirical evidence in support of long-held theories of the development of BPD. Together, these trends suggest that for the first time, empirical findings are beginning to emerge in support of complex and reciprocal biology × environment interactions over time in the development of BPD. We discuss the emerging literature and highlight the translational impact of this work for the assessment and intervention of adolescent BPD.

If It Looks Like a Duck and Quacks Like a Duck: Evaluating the Validity of Borderline Personality Disorder in Adolescents

Background:

The validity of borderline personality disorder (BPD) has been a topic of much controversy in psychiatry. Over the last two decades, a wealth of empirical work has challenged long-held concerns regarding the validity of adolescent BPD. However, this research has been conducted within a traditional approach to psychiatric nosology.

Objective:

In this article, we aim to evaluate the validity of adolescent BPD as guided by both the Robins and Guze criteria for the validity of psychiatric constructs and the new National Institute of Mental Health Research Domain Criteria (NIMH RDoC).

Method:

We used the five principles of the Robins and Guze approach to evaluate selected research from our own and other groups regarding the validity of adolescent BPD. These principles include clinical description studies, laboratory studies, studies that delimitate the disorder from other related syndromes, follow-up studies, and family studies.

Results:

Within the Robins and Guze criteria framework, evidence to date supports the validity of adolescent BPD to some extent. However, limitations of the research about the construct validity of adolescent BPD have also been identified, most notably regarding the delimitation of adolescent BPD from other disorders as well as a lack of longitudinal and family studies.

Conclusions:

Given these limitations and the limitations of the Robins and Guze approach to psychiatric nosology, we recommend exploring the potential of the National Institute of Mental Health Research Domain Criteria as a complement to previous work.

Association between genetic polymorphisms in the serotonergic system and comorbid personality disorders among patients with first-episode depression

Studies on the association between genetic polymorphisms and personality disorders have provided inconsistent results. Using the "enriched sample method," the authors of the present study aimed to assess the association between polymorphisms in the serotonergic transmitter system and comorbid personality disorders in patients recently diagnosed with first-episode depression. A total of 290 participants were systematically recruited via the Danish Psychiatric Central Research Register. Diagnoses of personality disorders were assessed by a SCID-II interview, and polymorphisms in the genes encoding the serotonin transporter, serotonin receptors 1A, 2A, 2C, and tryptophan hydroxylase 1 were genotyped. The authors found a significant effect of the length polymorphism in the serotonin transporter gene (5-HTTLPR) on cluster B personality disorder (mainly borderline disorder), but no influence on cluster C personality disorder, and no associations between other polymorphisms and personality disorders. The study adds evidence to the effect of the serotonin transporter gene specifically on cluster B personality disorders.

The interactive effect of MAOA-LPR genotype and childhood physical neglect on aggressive behaviors in Italian male prisoners

Aggressive disorders are moderately heritable; therefore, identification of genetic influences is important. The X-linked MAOA gene, encoding the MAOA enzyme, has a functional 30 bp repeat polymorphism in the promoter region (MAOA-LPR) that has been shown to influence aggression. Childhood trauma is a known risk factor for numerous psychopathologies in adulthood including aggressive behaviors. We investigated the interactive effect of MAOA-LPR genotype and a history of childhood trauma in predicting aggressive behaviors in a prisoner population. A total of 692 male prisoners were genotyped for MAOA-LPR with genotypes grouped into high and low transcriptional activity. Participant evaluations included measures of aggression (Brown-Goodwin Lifetime History of Aggression, BGHA), hostility (Buss-Durkee Hostility Inventory), impulsivity (Barratt Impulsiveness Scale), violence directed toward self and others, and childhood trauma [Childhood Trauma Questionnaire (CTQ)]. MAOA-LPR interacted with CTQ physical neglect (PN), the most common (47%) form of childhood trauma in this sample, to predict BGHA aggression (P = 0.002). Within the group not exposed to PN, carriers of the MAOA-LPR high-activity variant were more aggressive: (tR = 2.47, P < 0.014). We observed a crossover effect in that the increase in aggression scores with PN was greater in low-activity individuals (tR = 5.55, P < 0.0001) than in high-activity individuals (tR = 4.18, P < 0.0001). These findings suggest that childhood trauma and the functional MAOA-LPR polymorphism may interact to specifically increase risk for over aggressive behavior but not impulsivity or hostility. The MAOA-LPR low-activity variant may be protective against the development of aggressive behavior under low stress conditions, at least in this prisoner population.

The association of 5-HTR2A-1438A/G, COMTVal158Met, MAOA-LPR, DATVNTR and 5-HTTVNTR gene polymorphisms and borderline personality disorder in female heroin-dependent Chinese subjects

OBJECTIVE

To explore the association between the 5-HTR2A-1438A/G, COMTVal158Met, MAOA-LPR, DATVNTR and 5-HTTVNTR polymorphisms with co-morbid borderline personality disorder (BPD) in female heroin-dependent patients.

SUBJECTS AND METHODS

In a case control study, we compared the polymorphic distributions of 5-HTR2A-1438A/G, COMTVal158Met, MAOA-LPR, DATVNTR and 5-HTTVNTR in 296 female heroin-dependent patients (including 61 patients with BPD and 235 without BPD) and 101 normal females by genotypes, alleles, and interaction between genes.

RESULTS

Female heroin-dependent subjects with BPD have lower frequency of the high activity allele (L: 4 repeats (4R)) of MAOA-LPR than those female heroin-dependent subjects without BPD, and have higher 5-HTTVNTR 10R/10R genotype frequency than normal female controls, with adjusted P-value<0.05 (after adjusted for multiple testing by 1000-fold permutation tests) respectively. By MDR (Multifactor Dimensionality Reduction) analyses, the interactive effects between MAOA-LPR and 5-HTTVNTR, and among MAOA-LPR, 5-HTTVNTR and rs6311 were close to the significance level (P=0.05) in predicting the risk of co-morbidity of BPD and heroin dependence relative to normal female controls, with 1000-fold permutation testing P-value<0.06 however >0.05 respectively.

CONCLUSION

5-HTTVNTR and MAOA-LPR may have independent predictive effects on co-morbid BPD in female heroin-dependent patients; the gene-gene interactions between MAOA-LPR and 5-HTTVNTR, and among MAOA-LPR, 5-HTTVNTR and rs6311 might also be involved in the etiology of this co-morbidity.

Association study between monoamine oxidase A (MAOA) gene polymorphisms and schizophrenia: lack of association with schizophrenia and possible association with affective disturbances of schizophrenia

Monoamine oxidase A (MAOA) catalyzes monoamine neurotransmitters including dopamine, 5-hydroxytryptamine (5-HT, serotonin), and norepinephrine. MAOA also plays a key role in emotional regulation. The aim of this study was to investigate the associations between the exonic single nucleotide polymorphisms (SNPs) of the MAOA gene located on the X chromosome and schizophrenia. We also analyzed the relationships between these SNPs and the common clinical symptoms of schizophrenia such as persecutory delusion, auditory hallucinations, affective disturbances, and poor concentration. Two hundred seventy five Korean schizophrenia patients and 289 control subjects were recruited. Three SNPs [rs6323 (Arg294Arg), rs1137070 (Asp470Asp), and rs3027407 (3'-untranslated region)] of the MAOA gene were selected and genotyped by direct sequencing. The common clinical symptoms of schizophrenia according to the Operation Criteria Checklist were analyzed. Three examined SNPs showed no associations with male and female schizophrenia, respectively (p>0.05). In the analysis of the common clinical symptoms of schizophrenia patients, three examined SNPs were associated with affective disturbances, especially restricted affect and blunted affect in male schizophrenia, respectively (restricted affect, p=0.002, OR=2.71, 95% CI 1.45-5.00; blunted affect, p=0.009, OR 2.25, 95% CI 1.22-4.12). The SNPs were not associated with other clinical symptoms of schizophrenia (persecutory delusion, auditory hallucinations, and poor concentration). These results suggest that exonic SNPs (rs6323, rs1137070, and rs3027407) of the MAOA gene may be contributed to affective disturbances of Korean males schizophrenia, especially restricted affect and blunted 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.

Food-derived serotonergic modulators: effects on mood and cognition

The most frequently described drugs in the treatment of mood disorders are selective serotonin reuptake and monoamine oxidase (MAO) inhibitors, enhancing serotonin levels in the brain. However, side-effects have been reported for these drugs. Because serotonin levels in the brain are dependent on the availability of the food-derived precursor tryptophan, foods such as chicken, soyabeans, cereals, tuna, nuts and bananas may serve as an alternative to improve mood and cognition. Here we discuss the effects of high- or low-tryptophan-containing food, as well as plant extracts with a modest monoamine reuptake and MAO-A inhibition functional profile, on mood and cognition in healthy and vulnerable human subjects and rodents. Together the studies suggest that there is an inverted U-shaped curve for plasma tryptophan levels, with low and too high tryptophan levels impairing cognition, and moderate to high tryptophan levels improving cognition. This relationship is found for both healthy and vulnerable subjects. Whereas this relationship may also exist for mood, the inverted U-shaped curve for plasma tryptophan levels and mood may be based on different tryptophan concentrations in healthyv.vulnerable individuals. Animal studies are emerging and allow further understanding of effects and the mode of action of food-derived serotonergic components on mood, cognition and mechanisms. Ultimately, insight into the concentrations of tryptophan and other serotonergic components in food having beneficial effects on mood and cognition in healthy, but particularly vulnerable, subjects may support well-being in our highly demanding society.

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.

Mentalizing-based treatment with adolescents and families

In this article, the process of mentalizing, its components, and role in self-regulation and attachment are reviewed. An examination is presented of the neurodevelopmental changes affecting the adolescent's capacity to mentalize and the role of such compromised mentalizing in the adolescent's vulnerability to adaptive breakdown and psychopathology, in general, and to emerging personality disorders, in particular. The principles, objectives, and core features of mentalizing-based treatment and its application to adolescents and families are discussed.

The association of bipolar spectrum disorders and borderline personality disorder

Bipolar disorder (BD) and borderline personality disorder (BPD) are two different entities sharing a variety of common features in a number of fields and, thus, presenting difficulties in their differential diagnosis. The aim of the review is to identify similarities and differences between BD and BPD concerning the symptomatology, causes, course and treatment of the two disorders. A systematic electronic search of Pubmed (Medline) was conducted in order to identify all relevant scientific articles published between 1990 and 2010. The main common clinical features of BD and BPD are affective instability and impulsivity, which, however, present with quality differences in each disorder. In the field of neuroanatomy, BD and BPD demonstrate similarities such as alterations in the limbic system, as well as specific differences, such as the increase in size of the amygdala in BD and the decrease in BPD. Both disorders appear to have a significant percentage of heritability, but environmental factors seem to hold an important role in BPD, in particular. Both BD and BPD are affected by alterations in the dopaminergic and serotonergic system. Fuctionability and prognosis are slightly worse for BPD. Concerning medication treatment, antidepressants are considered effective in BPD, whereas mood stabilizers are the main treatment of choice in BD. The effectiveness of a variety of psychotherapeutic methods is still under research for both disorders. Despite the similarities and differences already being traced in clinical and biological fields, the relationship of the two disorders has not yet been thoroughly defined.

The c.1460C>T polymorphism of MAO-A is associated with the risk of depression in postmenopausal women

OBJECTIVE

The aim of the study was an evaluation of possible relationships between polymorphisms of serotoninergic system genes and the risk of depression in postmenopausal women.

METHODS

We studied 332 women admitted to our department because of climacteric symptoms. The study group included 113 women with a diagnosis of depressive disorder according to the Hamilton rating scale for depression; the controls consisted of 219 women without depression. Serum 17β-estradiol concentrations were evaluated using radioimmunoassay, while polymorphisms in serotoninergic system genes: serotonin receptors 2A (HTR2A), 1B (HTR1B), and 2C (HTR2C); tryptophan hydroxylase 1 (TPH1) and 2 (TPH2), and monoamine oxidase A (MAO-A) were evaluated using polymerase chain reaction-restriction.

RESULTS

We found that the 1460T allele of MAO-A c.1460C>T (SNP 1137070) appeared with a significantly higher frequency in depressed female patients than in the control group (P = 0.011) and the combined c.1460CT + TT genotypes were associated with a higher risk of depression (P = 0.0198). Patients with the 1460TT genotype had a significantly higher 17β-estradiol concentration than patients with the 1460CT genotype (P = 0.0065) and 1460CC genotype (P = 0.0018).

CONCLUSIONS

We concluded that depression in postmenopausal women is closely related to the genetic contribution of MAO-A.

Developmental pathways to borderline personality disorder

This paper reviews recent studies of biological and environmental risk and protective factors and patterns of continuity leading to borderline personality disorder (BPD). It focuses on prospective studies of children and adolescents and studies of young people with borderline pathology, reporting findings from genetics, neurobiology, experimental psychopathology, environmental risk, and precursor signs and symptoms. Studies of individuals earlier in the course of BPD demonstrate relatively consistent environmental risk factors, but neurobiological and experimental psychopathology findings are still inconsistent. Also, temperamental and mental state abnormalities that resemble aspects of the BPD phenotype emerge in childhood and adolescence and presage the BPD syndrome in adolescence or adulthood. Further work is required to better understand the roles that all these factors play in the developmental pathways to BPD and to increase their specificity for BPD in order to facilitate prevention and early intervention.

Prefrontal cortex lesions and MAO-A modulate aggression in penetrating traumatic brain injury

OBJECTIVE

This study investigates the interaction between brain lesion location and monoamine oxidase A (MAO-A) in the genesis of aggression in patients with penetrating traumatic brain injury (PTBI).

METHODS

We enrolled 155 patients with PTBI and 42 controls drawn from the Vietnam Head Injury Study registry. Patients with PTBI were divided according to lesion localization (prefrontal cortex [PFC] vs non-PFC) and were genotyped for the MAO-A polymorphism linked to low and high transcriptional activity. Aggression was assessed with the aggression/agitation subscale of the Neuropsychiatric Inventory (NPI-a).

RESULTS

Patients with the highest levels of aggression preferentially presented lesions in PFC territories. A significant interaction between MAO-A transcriptional activity and lesion localization on aggression was revealed. In the control group, carriers of the low-activity allele demonstrated higher aggression than high-activity allele carriers. In the PFC lesion group, no significant differences in aggression were observed between carriers of the 2 MAO-A alleles, whereas in the non-PFC lesion group higher aggression was observed in the high-activity allele than in the low-activity allele carriers. Higher NPI-a scores were linked to more severe childhood psychological traumatic experiences and posttraumatic stress disorder symptomatology in the control and non-PFC lesion groups but not in the PFC lesion group.

CONCLUSIONS

Lesion location and MAO-A genotype interact in mediating aggression in PTBI. Importantly, PFC integrity is necessary for modulation of aggressive behaviors by genetic susceptibilities and traumatic experiences. Potentially, lesion localization and MAO-A genotype data could be combined to develop risk-stratification algorithms and individualized treatments for aggression in PTBI.

Psychopathy, PCL-R, and MAOA genotype as predictors of violent reconvictions

The Revised Psychopathy Checklist (PCL-R) has shown a moderate association with violence. The efficacy of PCL-R in varying monoamine oxidase A (MAOA) genotypes is, however, unexamined. The aim of this study was to investigate the effect of PCL-R and psychopathy on the risk for violent reconvictions among 167 MAOA genotyped alcoholic offenders. Violent reconvictions and PCL-R scores among violent offenders were assessed after a 7-year non-incarcerated follow-up. Regression analysis was used to evaluate the alcohol exposure and age-adjusted effect of PCL-R score and psychopathy on the risk for reconvictions among differing MAOA genotypes. Results suggest that the PCL-R total score predicts impulsive reconvictions among high-activity MAOA offenders (6.8% risk increase for every one-point increase in PCL-R total score, P = 0.015), but not among low-activity MAOA offenders, whereas antisocial behavior and attitudes predicted reconvictions in both genotypes (17% risk increase among high-activity MAOA offenders and 12.8% increase among low-activity MAOA offenders for every one-point increase in factor 2 score). Both narcissistic self-image with related interpersonal style (factor 1 score) and psychopathy (PCL-R ≥ 30) failed to predict future violence. Results suggest that the efficacy of PCL-R is altered by MAOA genotype, alcohol exposure, and age, which seems important to note when PCL-R is used for risk assessments that will have legal or costly preventive work consequences.

[Contribution of neurobiology to our knowledge of borderline personality disorder]

Affect dysregulation and impulsivity are the main topics of neurobiological research in borderline personality disorder. Affect dysregulation subsumes enhanced resting arousal, increased emotional responsiveness as well as deficient emotional regulation and is associated with structural and functional abnormalities in a prefrontal-limbic network, above all orbitofrontal hypoactivity and amygdalar as well as insular hyperactivity. Impulsivity describes a lack of future-oriented problem solving style as well as a decreased threshold for motoric responses and is associated with decreased serotonergic activity in the ventral prefrontal cortex. Future research has to clarify how specific the findings of borderline personality disorder are and how far temperament dimensions, such as neuroticism can explain the neurobiological deviations from the norm.

Predisposition for borderline personality disorder with comorbid major depression is associated with that for polycystic ovary syndrome in female Japanese population

Polycystic ovary syndrome (PCOS) is a common lifestyle-related endocrinopathy in women of reproductive age and is associated with several mental health problems. We examined the genotypic distributions of IRS-1 Gly972Arg and CYP11B2 -344T/C, which were previously described as influencing PCOS, and assayed the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), in a set of female patients with borderline personality disorder (BPD) with comorbid major depressive disorder (MDD) (n = 50) and age-matched control subjects (n = 100), to investigate the predisposition for BPD with MDD. The results showed that the patients were more frequently IRS-1 972Arg variant allele carriers (P = 0.013; OR 6.68; 95% CI = 1.30-34.43) and homozygous for the CYP11B2 -344C variant allele (P = 0.022; OR = 3.32; 95% CI = 1.18-9.35) than the control subjects. The IL-6 level was significantly higher in the patients than in the controls (P < 0.0001). There was no significant difference in the serum TNF-α level between patients with BPD with MDD and the healthy comparison group (P = 0.5273). In conclusion, the predisposition for BPD with MDD is associated with that for PCOS, in the female Japanese population. An elevated serum IL-6 level is considered to be a possible biomarker of BPD with MDD.

Borderline personality disorder

Recent research findings have contributed to an improved understanding and treatment of borderline personality disorder. This disorder is characterised by severe functional impairments, a high risk of suicide, a negative effect on the course of depressive disorders, extensive use of treatment, and high costs to society. The course of this disorder is less stable than expected for personality disorders. The causes are not yet clear, but genetic factors and adverse life events seem to interact to lead to the disorder. Neurobiological research suggests that abnormalities in the frontolimbic networks are associated with many of the symptoms. Data for the effectiveness of pharmacotherapy vary and evidence is not yet robust. Specific forms of psychotherapy seem to be beneficial for at least some of the problems frequently reported in patients with borderline personality disorder. At present, there is no evidence to suggest that one specific form of psychotherapy is more effective than another. Further research is needed on the diagnosis, neurobiology, and treatment of borderline personality disorder.

Tryptophan-hydroxylase 2 haplotype association with borderline personality disorder and aggression in a sample of patients with personality disorders and healthy controls

BACKGROUND

There is a decreased serotonergic function in impulsive aggression and borderline personality disorder (BPD), and genetic association studies suggest a role of serotonergic genes in impulsive aggression and BPD. Only one study has analyzed the association between the tryptophan-hydroxylase 2 (TPH2) gene and BPD. A TPH2 "risk" haplotype has been described that is associated with anxiety, depression and suicidal behavior.

METHODS

We assessed the relationship between the previously identified "risk" haplotype at the TPH2 locus and BPD diagnosis, impulsive aggression, affective lability, and suicidal/parasuicidal behaviors, in a well-characterized clinical sample of 103 healthy controls (HCs) and 251 patients with personality disorders (109 with BPD). A logistic regression including measures of depression, affective lability and aggression scores in predicting "risk" haplotype was conducted.

RESULTS

The prevalence of the "risk" haplotype was significantly higher in patients with BPD compared to HCs. Those with the "risk" haplotype have higher aggression and affect lability scores and more suicidal/parasuicidal behaviors than those without it. In the logistic regression model, affect lability was the only significant predictor and it correctly classified 83.1% of the subjects as "risk" or "non-risk" haplotype carriers.

CONCLUSIONS

We found an association between the previously described TPH2 "risk" haplotype and BPD diagnosis, affective lability, suicidal/parasuicidal behavior, and aggression scores.

The genetic epidemiology of personality disorders

Genetic epidemiologic studies indicate that all ten personality disorders (PDs) classified on the DSM-IV axis II are modestly to moderately heritable. Shared environmental and nonadditive genetic factors are of minor or no importance. No sex differences have been identified. Multivariate studies suggest that the extensive comorbidity between the PDs can be explained by three common genetic and environmental risk factors. The genetic factors do not reflect the DSM-IV cluster structure, but rather: i) broad vulnerability to PD pathology or negative emotionality; ii) high impulsivity/low agreeableness; and iii) introversion. Common genetic and environmental liability factors contribute to comorbidity between pairs or clusters of axis I and axis II disorders. Molecular genetic studies of PDs, mostly candidate gene association studies, indicate that genes linked to neurotransmitter pathways, especially in the serotonergic and dopaminergic systems, are involved. Future studies, using newer methods like genome-wide association, might take advantage of the use of endophenotypes.

Efficacy and tolerability of duloxetine in the treatment of patients with borderline personality disorder: a pilot study

Guidelines of the American Psychiatric Association for borderline personality disorder (BPD) indicate selective serotonin reuptake inhibitors and the serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine for treating affective dysregulation and impulsive behavioural dyscontrol symptoms. The SNRI duloxetine has been studied in patients with major depression, generalized anxiety disorder and fibromyalgia, showing particular efficacy on somatic complaints. This study investigates duloxetine in the treatment of patients with BPD. Eighteen outpatients with a DSM-IV-TR diagnosis of BPD were treated with open-label duloxetine, 60 mg/day, for 12 weeks. Patients were assessed at baseline, week 4 and 12 with the CGI Severity item, the BPRS, the HAM-D, the HAM-A, the SOFAS, the BPD Severity Index (BPDSI) and the HSCL-90-Somatization Subscale (HSCL-90 SOM). Adverse effects were evaluated using the Dosage Record Treatment Emergent Symptom Scale. Statistics were performed with the analysis of variance. Significant P values were <or=0.05. Fourteen patients completed the study. Four patients (22.2%) discontinued treatment in the first 4 weeks because of non-compliance. A significant change was found for: BPRS, HAM-D, SOFAS, BPDSI total score and items 'impulsivity', 'outbursts of anger' and 'affective instability' and HSCL-90 SOM. Adverse effects were mild headache and nausea. Initial results suggest that duloxetine is an effective and well-tolerated treatment for BPD, with positive effects on somatic symptoms.

MAOA alters the effects of heavy drinking and childhood physical abuse on risk for severe impulsive acts of violence among alcoholic violent offenders

BACKGROUND

A polymorphism in the promoter region of the monoamine oxidase A gene (MAOA) has been shown to alter the effect of persistent drinking and childhood maltreatment on the risk for violent and antisocial behaviors. These findings indicate that MAOA could contribute to inter-individual differences in stress resiliency.

METHODS

Recidivism in severe violent crimes was assessed after 8 years of nonincarcerated follow-up in a male sample of 174 impulsive Finnish alcoholic violent offenders, the majority of whom exhibited antisocial (ASPD) or borderline personality disorder (BPD) or both. We examined whether MAOA genotype alters the effects of heavy drinking and childhood physical abuse (CPA) on the risk for committing impulsive recidivistic violent crimes.

RESULTS

Logistic regression analyses showed that both heavy drinking and CPA were significant independent predictors of recidivism in violent behavior (OR 5.2, p = 0.004 and OR 5.3, p = 0.003) among offenders having the high MAOA activity genotype (MAOA-H), but these predictors showed no effect among offenders carrying the low MAOA activity genotype (MAOA-L).

CONCLUSION

Carriers of the MAOA-H allele have a high risk to commit severe recidivistic impulsive violent crimes after exposure to heavy drinking and CPA.

Association analysis between gene variants of the tyrosine hydroxylase and the serotonin transporter in borderline personality disorder

OBJECTIVES

For patients with borderline personality disorder (BPD), we previously reported an independent effect of the catechol-o-methyl-transferase (COMT) low-activity (Met(158)) allele and an interaction with the low-expression allele of the deletion/insertion (short/long or S/L, resp.) polymorphism in the serotonin transporter-linked promoter region (5-HTTLPR). The purpose of the present study was to extend these findings to the tyrosine hydroxylase (TH) Val(81)Met single nucleotide polymorphism (SNP), the 5-HTTLPR S/L polymorphism incorporating the recently described functional A/G SNP within the long allele of the 5-HTTLPR (rs25531) as well as the variable number of tandem repeat (VNTR) polymorphism within intron 2 of the serotonin transporter gene (STin2).

METHODS

In 156 Caucasian BPD patients and 152 healthy controls, we tested for association between BPD and the TH Val(81)Met SNP, the 5-HTTLPR/rs25531 polymorphism, the STin2, the interaction of the TH Val(81)Met SNP with the tri-allelic 5-HTTLPR/rs25531, the interaction of the TH Val(81)Met SNP with STin2.

RESULTS

Between BPD patients and controls, we observed a slight over-representation of the TH Met(81)Met genotype in BPD patients compared to controls, but no statistically significant differences in genotype distribution of the individual markers after adjusting for multiple testing. Logistic regression analysis showed a lack of interaction between the TH Val(81)Met and the 5-HTTLPR/rs25531 as well as between the TH Val(81)Met and the STin2 polymorphism.

CONCLUSIONS

These data do not suggest independent or interactive effects of the TH Val(81)Met, the 5-HTTLPR/rs25531, or the STin2 polymorphisms in BPD.

A developmental, mentalization-based approach to the understanding and treatment of borderline personality disorder

The precise nature and etiopathogenesis of borderline personality disorder (BPD) continues to elude researchers and clinicians. Yet, increasing evidence from various strands of research converges to suggest that affect dysregulation, impulsivity, and unstable relationships constitute the core features of BPD. Over the last two decades, the mentalization-based approach to BPD has attempted to provide a theoretically consistent way of conceptualizing the interrelationship between these core features of BPD, with the aim of providing clinicians with a conceptually sound and empirically supported approach to BPD and its treatment. This paper presents an extended version of this approach to BPD based on recently accumulated data. In particular, we suggest that the core features of BPD reflect impairments in different facets of mentalization, each related to impairments in relatively distinct neural circuits underlying these facets. Hence, we provide a comprehensive account of BPD by showing how its core features are related to each other in theoretically meaningful ways. More specifically, we argue that BPD is primarily associated with a low threshold for the activation of the attachment system and deactivation of controlled mentalization, linked to impairments in the ability to differentiate mental states of self and other, which lead to hypersensitivity and increased susceptibility to contagion by other people's mental states, and poor integration of cognitive and affective aspects of mentalization. The combination of these impairments may explain BPD patients' propensity for vicious interpersonal cycles, and their high levels of affect dysregulation and impulsivity. Finally, the implications of this expanded mentalization-based approach to BPD for mentalization-based treatment and treatment of BPD more generally are discussed.

The 5-HTTLPR polymorphism modulates the association of serious life events (SLE) and impulsivity in patients with Borderline Personality Disorder

BACKGROUND

Impulsivity belongs to the key features of Borderline Personality Disorder (BPD). It has been linked to altered serotoninergic neurotransmission and, genetically, to an over-representation of the short (S) allele of the serotonin transporter promoter-linked polymorphic region polymorphism (5-HTTLPR). On the other hand, serious life events (SLE) are of major importance in the development of BPD. However, the inter-relations between SLEs, impulsivity, and 5-HTTLPR are not understood.

METHOD

159 BPD patients from Germany were included in this study. Impulsivity was assessed by the Barratt Impulsiveness Scale (BIS). We analysed (1) the effects of SLEs on impulsivity; and (2) modulating effects of the 5-HTTLPR polymorphism on the effects of SLEs on impulsivity.

RESULTS

Regression analyses confirmed a decreasing effect of childhood sexual abuse, the cumulative SLE-related reactions and the impairment by SLEs on BIS sum score. Regarding BIS sum score, all SLEs except for rape were associated with a decrease of impulsivity in SS/SL carriers and an increase of BIS sum score in LL carriers.

CONCLUSIONS

This study analyzing a specific gene x environment interaction in BPD patients suggests an interaction between SLEs and the 5-HTTLPR S/L polymorphism in the development of impulsivity in BPD patients. Clinical and research implications are discussed.

Evaluation of behavioral impulsivity and aggression tasks as endophenotypes for borderline personality disorder

Borderline personality disorder (BPD) is marked by aggression and impulsive, often self-destructive behavior. Despite the severe risks associated with BPD, relatively little is known about the disorder's etiology. Identification of genetic correlates (endophenotypes) of BPD would improve the prospects of targeted interventions for more homogeneous subsets of borderline patients characterized by specific genetic vulnerabilities. The current study evaluated behavioral measures of aggression and impulsivity as potential endophenotypes for BPD. Subjects with BPD (N=127), a non cluster B personality disorder (OPD N=122), or healthy volunteers (HV N=112) completed self report and behavioral measures of aggression, motor impulsivity and cognitive impulsivity. Results showed that BPD subjects demonstrated more aggression and motor impulsivity than HV (but not OPD) subjects on behavioral tasks. In contrast, BPD subjects self-reported more impulsivity and aggression than either comparison group. Subsequent analyses showed that among BPD subjects behavioral aggression was associated with self-reported aggression, while behavioral and self-report impulsivity measures were more modestly associated. Overall, the results provide partial support for the use of behavioral measures of aggression and motor impulsivity as endophenotypes for BPD, with stronger support for behavioral aggression measures as an endophenotype for aggression within BPD samples.

Interaction between gene variants of the serotonin transporter promoter region (5-HTTLPR) and catechol O-methyltransferase (COMT) in borderline personality disorder

Borderline personality disorder (BPD) is characterized by a heterogeneous symptomatology with instability in impulse control, interpersonal relationships and self-image. BPD patients display repeated self-injury, chronic suicidal tendencies and emotional dysregulation, mainly dysregulation of negative affect. In its etiology, genetic and environmental factors have been suggested. Recently, an investigation in male healthy volunteers found gene-gene effects of the catechol-O-methyl-transferase (COMT) low-activity (Met(158)) and the low-expression allele of the deletion/insertion (short/long or S/L, respectively) polymorphism in the serotonin transporter-linked promoter region (5-HTTLPR) on the central processing of aversive stimuli. The purpose of the present study was to test for association between BPD and the COMT Val(158)Met single nucleotide polymorphism (SNP), the 5-HTTLPR S/L variant and the interaction of these two gene variants. One hundred sixty one well-defined Caucasian BPD patients and 156 healthy controls were recruited from central Germany. In BPD patients, the genotype COMT Met(158)Met was over-represented compared to healthy controls (P = 0.0085; adjusted P = 0.034). We observed no differences in 5-HTTLPR genotypes between BPD and controls (P = 0.286). Additionally, the COMT Met(158)Met genotype was significantly over-represented in BPD patients carrying at least one 5-HTTLPR S allele (P = 0.0007; adjusted P = 0.028). Logistic regression analysis confirmed an interaction of the COMT Met(158) and the 5-HTTLPR S allele (P = 0.001). These data suggest an involvement of altered dopaminergic and/or noradrenergic neurotransmission as well as an interactive effect of COMT and 5-HTTLPR gene variants in the etiology of BPD, and underline the usefulness of analyses of gene-gene effects in diseases of complex inheritance with multiple genes involved.

The neurobiology of personality disorders: implications for psychoanalysis

As advances in neuroscience have furthered our understanding of the role of brain circuitry, genetics, stress, and neuromodulators in the regulation of normal behavior and in the pathogenesis of psychopathology, an increasing appreciation of the role of neurobiology in individual differences in personality and their pathology in personality disorders has emerged. Individual differences in the regulation and organization of cognitive processes, affective reactivity, impulse/action patterns, and anxiety may in the extreme provide susceptibilities to personality disorders such as borderline and schizotypal personality disorder. A low threshold for impulsive aggression, as observed in borderline and antisocial personality disorders, may be related to excessive amygdala reactivity, reduced prefrontal inhibition, and diminished serotonergic facilitation of prefrontal controls. Affective instability may be mediated by excessive limbic reactivity in gabaminergic/glutamatergic/cholinergic circuits, resulting in an increased sensitivity or reactivity to environmental emotional stimuli as in borderline personality disorder and other cluster B personality disorders. Disturbances in cognitive organization and information processing may contribute to the detachment, desynchrony with the environment, and cognitive/perceptional distortions of cluster A or schizophrenia spectrum personality disorders. A low threshold for anxiety may contribute to the avoidant, dependent, and compulsive behaviors observed in cluster C personality disorders. These alterations in critical regulatory domains will influence how representations of self and others are internalized. Aspects of neurobiological functioning themselves become cognized through the medium of figurative language into an ongoing narrative of the self, one that can be transformed through the analytic process, allowing for the modulation of genetic/biological thresholds.

Serotonin genes and gene-gene interactions in borderline personality disorder in a matched case-control study

Lines of evidence suggest serotonin genes are susceptibility candidates in borderline personality disorder (BPD). However, few molecular genetic studies on BPD have been reported, especially an overall lack of study on epistatic interactions. We genotyped 27 polymorphisms in 7 serotonin genes in 113 Caucasian BPD patients and matched (sex, age and ethnicity) controls. Program UNPHASED was used to perform association analyses for genotypes, alleles and haplotypes with a permutation test of 10,000 simulations. The Multifactor Dimensionality Reduction analysis was used to examine gene-gene interactions in serotonin system, including three other genes (5-HTT, 5-HT2A and MAOA) that we previously reported. Genotype and allele analyses showed that BPD significantly associated with 5-HT2C and TPH2. BPD patients had high frequencies of the 5-HT2C rs6318G allele (p=0.021) and G/G genotype (OR=2.25); and TPH2 rs2171363T allele (p=0.001) and T containing genotypes (OR=3.40). The 5-HT1A, 5-HT1B, 5-HT1D, 5-HT3A and TPH1 showed no significant association with BPD for genotype, allele and haplotype analyses. We also detected significant interactions between 5-HT2C and TPH2 (p=0.001), and among 5-HT2C, 5-HTT, MAOA and TPH2 (p=0.001) in BPD. Patients with 5-HT2C rs6318G/G genotype had a high frequency of TPH2 rs2171363C/T genotype compared with controls. Our study indicates ""that serotonin genes and their interactions may play a role in the susceptibility to borderline personality disorder.

Reduced amygdala-prefrontal coupling in major depression: association with MAOA genotype and illness severity

The amygdala plays a pivotal role in a cortico-limbic circuitry implicated in emotion processing and regulation. In the present study, functional connectivity of the amygdala with prefrontal areas involved in emotion regulation was investigated during a facial expression processing task in a sample of 34 depressed inpatients and 31 healthy controls. All patients were genotyped for a common functional variable number tandem repeat (VNTR) polymorphism in the promoter region of the monoamine oxidase A gene (MAOA u-VNTR) which has been previously associated with major depression as well as reduced cortico-limbic connectivity in healthy subjects. In our control group, we observed tight coupling of the amygdala and dorsal prefrontal areas comprising the dorsolateral prefrontal cortex (DLPFC), dorsal parts of the anterior cingulate cortex (dACC), and lateral orbitofrontal cortex. Amygdala-prefrontal connectivity was significantly reduced in depressed patients and carriers of the higher active MAOA risk alleles (MAOA-H). Hence, depressed MAOA-H carriers showed the weakest amygdala-prefrontal coupling of the investigated subgroups. Furthermore, reduced coupling of this circuitry predicted more than 40% variance of clinical variables characterizing a longer and more severe course of disease. We conclude that genetic variation in the MAOA gene may affect the course of major depression by disrupting cortico-limbic connectivity.

Association analysis of SCN9A gene variants with borderline personality disorder

Borderline personality disorder (BPD) is a serious psychiatric disorder affecting about 1-2% of the general population. Key features of BPD are emotional instability, strong impulsivity, repeated self-injurious behavior (SIB) and dissociation. In the etiology of BPD and its predominant symptoms, genetic factors have been suggested. The voltage-gated sodium channel Nav1.7 is expressed in sensory neurons and in the hippocampus, a key region of the limbic system probably dysfunctional in BPD and dissociative disorders. The alpha-subunit of Nav1.7 is encoded by the SCN9A gene on chromosome 2 and variations of SCN9A can lead to complete inability to sense pain. The aim of the present study was to test for associations between SCN9A gene variants and BPD as well as BPD-related phenotypes. We genotyped ten tagging single nucleotide polymorphisms (SNPs) within the SCN9A gene in 161 well-defined Caucasian BPD patients and 156 healthy controls. We found no globally significant association of SCN9A markers with BPD at level 5%. However, in the female and in the male subsample, different SCN9A markers and individual haplotypes showed uncorrected p-values<0.05. In addition, p-values<0.05 were observed in the analysis of associations between SCN9A markers and dissociative symptoms. Although our results were largely negative, replication studies in an independent sample are warranted to follow up on the potential role of SCN9A gene variants in BPD and dissociative symptoms, paying special attention to a possible gender different etiology.

Genetics of personality disorders

This review of the literature on genetic contributions to the etiology of personality disorders broadly follows the DSM classification, and begins by evaluating the current evidence for genetic influences on the DSM axis II disorders. One of the most exciting directions in psychiatric genetics is the rapidly developing field of molecular genetic studies aiming to identify specific genes correlated with psychiatric phenotypes. Personality disorders, like most other psychiatric diagnostic categories, are etiologically complex, which implies that they are influenced by several genes and several environmental factors. The interplay between genes and the environment is a field that is receiving increasing attention and is addressed both in relation to quantitative and molecular methods.

Recent advances in the biological study of personality disorders

While it is premature to provide a simple model for the vulnerability to the development of either borderline (BPD) or schizotypal (SPD) personality disorder, it is clear that these heritable disorders lend themselves to fruitful neurobiological exploration. The most promising findings in BPD suggest that a diminished top-down control of affective responses, which is likely to relate to deceased responsiveness of specific midline regions of prefrontal cortex, may underlie the affective hyperresponsiveness in this disorder. In addition, genetic and neuroendocrine and molecular neuroimaging findings point to a role for serotonin in this affective disinhibition. Clearly SPD falls within the schizophrenia spectrum, but precisely the nature of what predicts full-blown schizophrenia as opposed to the milder symptoms of SPD is not yet clear.

Neurobiology of aggression and violence

Acts of violence account for an estimated 1.43 million deaths worldwide annually. While violence can occur in many contexts, individual acts of aggression account for the majority of instances. In some individuals, repetitive acts of aggression are grounded in an underlying neurobiological susceptibility that is just beginning to be understood. The failure of "top-down" control systems in the prefrontal cortex to modulate aggressive acts that are triggered by anger provoking stimuli appears to play an important role. An imbalance between prefrontal regulatory influences and hyper-responsivity of the amygdala and other limbic regions involved in affective evaluation are implicated. Insufficient serotonergic facilitation of "top-down" control, excessive catecholaminergic stimulation, and subcortical imbalances of glutamatergic/gabaminergic systems as well as pathology in neuropeptide systems involved in the regulation of affiliative behavior may contribute to abnormalities in this circuitry. Thus, pharmacological interventions such as mood stabilizers, which dampen limbic irritability, or selective serotonin reuptake inhibitors (SSRIs), which may enhance "top-down" control, as well as psychosocial interventions to develop alternative coping skills and reinforce reflective delays may be therapeutic.