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

Molecular Changes Associated with Suicide

Suicide is a serious global public health problem, with a worrying recent increase in suicide rates in both adolescent and adult populations. However, it is essential to recognize that suicide is preventable. A myriad of factors contributes to an individual's vulnerability to suicide. These factors include various potential causes, from psychiatric disorders to genetic and epigenetic alterations. These changes can induce dysfunctions in crucial systems such as the serotonergic, cannabinoid, and hypothalamic-pituitary-adrenal axes. In addition, early life experiences of abuse can profoundly impact an individual's ability to cope with stress, ultimately leading to changes in the inflammatory system, which is a significant risk factor for suicidal behavior. Thus, it is clear that suicidal behavior may result from a confluence of multiple factors. This review examines the primary risk factors associated with suicidal behavior, including psychiatric disorders, early life adversities, and epigenetic modifications. Our goal is to elucidate the molecular changes at the genetic, epigenetic, and molecular levels in the brains of individuals who have taken their own lives and in the plasma and peripheral mononuclear cells of suicide attempters and how these changes may serve as predisposing factors for suicidal tendencies.

COMT Val/Met and Psychopathic Traits in Children and Adolescents: A Systematic Review and New Evidence of a Developmental Trajectory toward Psychopathy

Psychopathic traits in youth may lead to adult criminal behaviors/psychopathy. The Val158Met polymorphism of catechol-O-methyltransferase (COMT) may influence the risk for psychopathy-related behaviors, while acting as a biomarker for predicting treatment response to dopaminergic medications. The literature shows inconsistent findings, making the interpretation of COMT's role difficult. The aims of this article are (i) to conduct a systematic review to analyze the effects of COMT Val158Met on psychopathic traits in children and adolescents, and (ii) to present new evidence on the developmental trajectory of the association of Val158Met and youth psychopathic traits. For the systematic review, a literature search was conducted using PubMed, EMBASE, OVID Medline and PsychINFO with the search terms for psychopathic traits, Val158Met and age of interest. In our genotype study, the COMT Val158Met genotype of 293 youth with European ancestry was analyzed in association with the psychopathy-related behavior scores from the Child Behavior Checklist and the Psychopathy Screening Device. To examine the potential influence of developmental changes, the sample was split into at or above and below age 13, and analyses were performed in males and females separately. The literature search yielded twenty-eight articles to be included in the systematic review, which demonstrated mixed results on the association depending on environmental factors, sex ratios, age groups and behavioral disorder diagnoses. The results from our genotype study revealed that Met homozygous youth in the below age 13 group and conversely Val carrier youth in the above age 13 group were more likely to display psychopathic traits. To our knowledge, this is the first study to systematically review the effects of COMT Val158Met on psychopathic traits in childhood and adolescence, and to provide new evidence on the changing effects of Val158Met on psychopathy-related behaviors with development. Elucidating the role of the COMT genotype in conjunction with the child versus adolescent stage of development for psychopathic traits may help predict treatment response, and may lead to early intervention and prevention strategies.

Oxytocin receptor gene, childhood maltreatment and borderline personality disorder features among male inmates in China

BACKGROUND

Borderline personality disorder (BPD) is caused by a variety of biological and environmental factors. Accumulating evidence suggests that childhood maltreatment is a risk environmental factor in the development of BPD, but research on the genetic pathology of BPD is still in its early stages, and very little is known about the oxytocin receptor (OXTR) gene. The purpose of this study is to further explore the interactive effects between OXTR gene polymorphisms and childhood maltreatment on BPD risk.

METHODS

Among the 1804 Chinese Han male inmates, 765 inmates who had BPD or antisocial personality disorder (ASPD) or highly impulsive or violent crime were considered as high-risk inmates and included in this study. Childhood maltreatment, BPD, antisocial personality disorder (ASPD) and impulsivity were measured by self-reported questionnaires. Peripheral venous blood was collected for the genotype test.

RESULTS

Analyses revealed that the BP group (inmates with BPD features) had higher rs53576 AA genotype frequency and rs237987 AA genotype frequency than the non-BP group, while the statistical significances were lost after Bonferroni correction. Total childhood maltreatment score, emotional abuse and neglect could positively predict BPD risk. Among the high-risk samples, rs53576 GG genotype carriers had higher BPD scores at higher levels of physical abuse and sexual abuse and had lower BPD scores at lower levels of physical abuse and sexual abuse.

CONCLUSIONS

The findings suggest that the interaction between OXTR gene variations and childhood maltreatment is an important mechanism for the development of BPD. The moderating role of the OXTR gene provides evidence for gene plasticity.

Preliminary Evidence for an Association Between Variants of the Catechol-O-Methyltransferase (COMT) Gene and Premature Ejaculation

BACKGROUND

Studies have suggested that dopamine plays a role in the neurobiological mechanism that triggers ejaculation, leading scientists to hypothesize that dopamine-related genetic polymorphisms could contribute to symptoms of premature ejaculation (PE).

AIM

To investigate associations between dopamine receptor and catechol-O-methyltransferase (COMT; an enzyme involved in the catabolism of dopamine) gene-linked polymorphisms and PE.

METHODS

PE status in patient groups was determined by clinical diagnosis performed by a physician specializing in sexual medicine. Self-reported PE symptoms from a validated questionnaire also were reported. Saliva samples were collected from 149 patients with PE and 1,022 controls from a population-based sample. In total, we tested associations between PE and 11 single-nucleotide polymorphisms in the dopamine receptor D1, D2, and D3 genes and in the COMT gene.

OUTCOMES

We found no associations between dopamine receptor gene polymorphisms and PE, but 2 COMT-linked loci (rs4680 and rs4818) had significant associations after correction for multiple testing.

RESULTS

1 COMT gene-linked locus that was associated with PE symptoms in the present study, rs4680, is a well-documented functional polymorphism that causes a valine-to-methionine substitution. The other polymorphism, rs4818, is in high linkage disequilibrium with the rs4680 locus, indicating that they capture the same effect. Surprisingly, the rs4680 variant that was statistically significantly more prevalent in the PE group (ie, the valine-encoding allele) has been associated with higher enzymatic activity and therefore lower synaptic dopamine levels.

CLINICAL TRANSLATION

Drugs targeting the dopaminergic system could affect PE symptoms.

STRENGTHS AND LIMITATIONS

No replication sample was available for the present study; thus, our findings should be interpreted with caution. Moreover, a limitation of our study is the small sample in the context of genetic association studies (although it should be mentioned that genetically informative samples with phenotypic information about PE symptoms are scarce, and most previous genetic association studies of PE have used samples of similar or smaller size). However, our results are plausible: we report an association between one of the most extensively studied and understood genetic polymorphisms in psychiatric research and PE, and our results are in line with the long-standing hypothesis that dopamine influences human ejaculatory function.

CONCLUSIONS

We report an association between 2 COMT gene-linked loci and PE symptoms, but our results should be treated with caution until independently replicated. Jern P, Johansson A, Strohmaier J, et al. Preliminary Evidence for an Association Between Variants of the Catechol-O-Methyltransferase (COMT) Gene and Premature Ejaculation. J Sex Med 2017;14:1558-1565.

The Role of the Catechol-o-Methyltransferase (COMT) GeneVal158Met in Aggressive Behavior, a Review of Genetic Studies

Aggressive behaviors have become a major public health problem, and early-onset aggression can lead to outcomes such as substance abuse, antisocial personality disorder among other issues. In recent years, there has been an increase in research in the molecular and genetic underpinnings of aggressive behavior, and one of the candidate genes codes for the catechol-O-methyltransferase (COMT). COMT is involved in catabolizing catecholamines such as dopamine. These neurotransmitters appear to be involved in regulating mood which can contribute to aggression. The most common gene variant studied in the COMT gene is the Valine (Val) to Methionine (Met) substitution at codon 158. We will be reviewing the current literature on this gene variant in aggressive behavior.

A Neurobiological Model of Borderline Personality Disorder: Systematic and Integrative Review

Borderline personality disorder (BPD) is a severe mental disorder with a multifactorial etiology. The development and maintenance of BPD is sustained by diverse neurobiological factors that contribute to the disorder's complex clinical phenotype. These factors may be identified using a range of techniques to probe alterations in brain systems that underlie BPD. We systematically searched the scientific literature for empirical studies on the neurobiology of BPD, identifying 146 articles in three broad research areas: neuroendocrinology and biological specimens; structural neuroimaging; and functional neuroimaging. We consolidate the results of these studies and provide an integrative model that attempts to incorporate the heterogeneous findings. The model specifies interactions among endogenous stress hormones, neurometabolism, and brain structures and circuits involved in emotion and cognition. The role of the amygdala in BPD is expanded to consider its functions in coordinating the brain's dynamic evaluation of the relevance of emotional stimuli in the context of an individual's goals and motivations. Future directions for neurobiological research on BPD are discussed, including implications for the Research Domain Criteria framework, accelerating genetics research by incorporating endophenotypes and gene × environment interactions, and exploring novel applications of neuroscience findings to treatment research.

An exploratory association study of the influence of noradrenergic genes and childhood trauma in Borderline Personality Disorder

This study investigated the possible association of 40 polymorphisms within 4 noradrenergic genes with BPD risk and the modulating effect of childhood trauma on these associations in 481 BPD subjects and 442 controls. COMT rs5993882, DBH rs77905 and SLC6A2 rs1814270 showed associations with BPD, which were modulated by childhood trauma. However, none of these findings survived Bonferroni correction. Further investigation is needed to clarify the involvement of these genes in BPD pathogenesis.

Association of DRD3, COMT, and SLC6A4 Gene Polymorphisms with Type 2 Diabetes in Southern Chinese: A Hospital-Based Case-Control Study

AIM

The aim of this study was to assess the associations of six single nucleotide polymorphisms (SNPs) of three genes (DRD3, COMT, and SCL6A4) with type 2 diabetes mellitus (T2DM) in Southern Chinese.

SUBJECTS AND METHODS

Five hundred ninety-five cases with T2DM and 725 healthy controls of Han origin were recruited from six hospitals in Guangdong Province, Southern China. Fasting serum concentrations of markers of interest (total cholesterol, triglyceride, plasma glucose, etc.) were measured in hospitals. SNP genotyping was performed using a custom-by-design 2-×48-Plex SNPscan™ kit (Genesky Biotechnologies Inc., Shanghai, China). Single-point SNP analysis, haplotype analysis, and SNP-SNP interactions were carried out.

RESULTS

SNP rs4646312 in COMT achieved statistical significance in both allelic association and genotypic association and even after adjusting covariates (odds ratio [OR]=1.26; 95% confidence interval [CI], 1.04-1.53; P=0.021). Two haplotypes consisting of rs4646312 and rs4680 were also significantly associated with T2DM, of which C-G was a protective haplotype for T2DM (OR=0.83; 95% CI, 0.70-0.98; P=0.029), whereas T-A was a risk one (OR=1.23, 95% CI, 1.03-1.46; P=0.022). Interaction analysis identified a significant epistatic effect between rs4680 in COMT and rs2066713 in SCL6A4 after adjusting for covariates (OR=3.59, 95% CI, 1.72-7.48; P=0.001 for dominant-dominant model). However, only the interaction between rs4680 and rs2066713 was significant, and haplotype T-A showed a marginally increased risk after Bonferroni correction.

CONCLUSIONS

The genetic polymorphisms in COMT and SCL6A4 confer significant effects in joint actions to T2DM in Southern Chinese.

Interaction between 5-HTTLPR and 5-HT1B genotype status enhances cerebral 5-HT1A receptor binding

Serotonergic neurotransmission is thought to underlie a dynamic interrelation between different key structures of the serotonin system. The serotonin transporter (SERT), which is responsible for the reuptake of serotonin from the synaptic cleft into the neuron, as well as the serotonin-1A (5-HT1A) and -1B (5-HT1B) receptors, inhibitory auto-receptors in the raphe region and projection areas, respectively, are likely to determine serotonin release. Thereby, they are involved in the regulation of extracellular serotonin concentrations and the extent of serotonergic effects in respective projection areas. Complex receptor interactions can be assessed in vivo with positron emission tomography (PET) and single-nucleotide-polymorphisms, which are thought to alter protein expression levels. Due to the complexity of the serotonergic system, gene × gene interactions are likely to regulate transporter and receptor expression and therefore subsequently serotonergic transmission. In this context, we measured 51 healthy subjects (mean age 45.5 ± 12.9, 38 female) with PET using [carbonyl-(11)C]WAY-100635 to determine 5-HT1A receptor binding potential (5-HT1A BPND). Genotyping for rs6296 (HTR1B) and 5-HTTLPR (SERT gene promoter polymorphism) was performed using DNA isolated from whole blood. Voxel-wise whole-brain ANOVA revealed a positive interaction effect of genotype groups (5-HTTLPR: LL, LS+SS and HTR1B: rs6296: CC, GC+GG) on 5-HT1A BPND with peak t-values in the bilateral parahippocampal gyrus. More specifically, highest 5-HT1A BPND was identified for individuals homozygous for both the L-allele of 5-HTTLPR and the C-allele of rs6296. This finding suggests that the interaction between two major serotonergic structures involved in serotonin release, specifically the SERT and 5-HT1B receptor, results in a modification of the inhibitory serotonergic tone mediated via 5-HT1A receptors.

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.

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.

Mechanisms of disturbed emotion processing and social interaction in borderline personality disorder: state of knowledge and research agenda of the German Clinical Research Unit

The last two decades have seen a strong rise in empirical research in the mechanisms of emotion dysregulation in borderline personality disorder. Major findings comprise structural as well as functional alterations of brain regions involved in emotion processing, such as amygdala, insula, and prefrontal regions. In addition, more specific mechanisms of disturbed emotion regulation, e.g. related to pain and dissociation, have been identified. Most recently, social interaction problems and their underlying neurobiological mechanisms, e.g. disturbed trust or hypersensitivity to social rejection, have become a major focus of BPD research. This article covers the current state of knowledge and related relevant research goals. The first part presents a review of the literature. The second part delineates important open questions to be addressed in future studies. The third part describes the research agenda for a large German center grant focusing on mechanisms of emotion dysregulation in BPD.

Association between low-activity allele of cathecolamine-O-methyl-transferase (COMT) and Borderline Personality Disorder in an Italian population

The objective of the present study was to test the association between Borderline Personality Disorder (BPD) and the cathecolamine-O-methyl-transferase (COMT) low-activity (Met158) single nucleotide polymorphism (SNP). In this case-control study, DNA was obtained from venous blood of 19 BPD patients and 36 healthy subjects. COMT-Val158Met single-nucleotide polymorphism was genotyped by predesigned SNP assay. The COMT Met158 allele was over-represented in patients with BPD in comparison to normal subjects (68.4% vs 44.4%, respectively; Fisher exact test, p = .02). In terms of genotype, the Met158Met subjects were more frequent in patients versus controls (47.4% vs 22.2%, respectively), whereas the high-activity genotype Val158Val was under-represented (10.5% vs 33.3%, respectively). The allele encoding for the COMT with low enzymatic efficiency was found to be over-represented in BPD, possibly resulting in excessive synaptic dopaminergic activity and ultimately affecting externalizing behaviours, such as impulsivity and aggressiveness.

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.

Impact of COMT genotype on serotonin-1A receptor binding investigated with PET

Alterations of the inhibitory serotonin-1A receptor (5-HT1A) constitute a solid finding in neuropsychiatric research, particularly in the field of mood and anxiety disorders. Manifold factors influencing the density of this receptor have been identified, e.g., steroid hormones, sunlight exposure and genetic variants of serotonin-related genes. Given the close interactions between serotonergic and dopaminergic neurotransmission, we investigated whether a common single-nucleotide-polymorphism of the catechol-O-methyltransferase (COMT) gene (VAL158MET or rs4680) coding for a key enzyme of the dopamine network that is associated with the pathogenesis of mood disorders and antidepressant treatment response, directly affects 5-HT1A receptor binding potential. Fifty-two healthy individuals (38 female, mean age ± standard deviation = 40.48 ± 14.87) were measured via positron emission tomography using the radioligand [carbonyl-(11)C]WAY-100635. Genotyping for rs4680 was performed using DNA isolated from whole blood with the MassARRAY platform of the software SEQUENOM(®). Whole brain voxel-wise ANOVA resulted in a main effect of genotype on 5-HT1A binding. Compared to A carriers (AA + AG) of rs4680, homozygote G subjects showed higher 5-HT1A binding potential in the posterior cingulate cortex (F (2,49) = 17.7, p = 0.05, FWE corrected), the orbitofrontal cortex, the anterior cingulate cortex, the insula, the amygdala and the hippocampus (voxel-level: p < 0.01 uncorrected, t > 2.4; cluster-level: p < 0.05 FWE corrected). In light of the frequently reported alterations of 5-HT1A binding in anxiety and mood disorders, this study proposes a potential implication of the COMT genotype, more specifically the VAL158MET polymorphism, via modulation of the serotonergic neurotransmission.

Interaction between genetic variants of DLGAP3 and SLC1A1 affecting the risk of atypical antipsychotics-induced obsessive-compulsive symptoms

Adverse effects of atypical antipsychotics (AAP) can include obsessive-compulsive (OC) symptoms. Based on biological evidence of the relationship between the glutamatergic system and both OC disorder and AAP, this study aimed to determine whether DLGAP3, coding a post-synaptic scaffolding protein of glutamatergic synapses, is associated with AAP-induced OC symptoms. Furthermore, we explored the interactions between DLGAP3 and a previously reported susceptibility gene, the glutamate transporter gene SLC1A1, regarding this phenotype. Subjects were clinically stable schizophrenia patients receiving AAP treatment (n = 94), and they comprised an OC group (n = 40) and a non-OC group (n = 54) (patients with and without AAP-induced OC symptoms, respectively). We performed allelic/genotypic/haplotype association analyses for seven tag single-nucleotide polymorphisms of DLGAP3 and gene-gene interaction analyses with rs2228622 of SLC1A1, observing a nominally significant association between AAP-induced OC symptoms and rs7525948 in both simple chi-square tests and the regression analyses (nominal P < 0.05). In the logistic regression analysis of gene-gene interaction, we found a significant interaction effect of rs7525948 of DLGAP3 and rs2228622 of SLC1A1 (permutation P = 0.036) on AAP-induced OC symptoms, with a 30.2 times higher odds for individuals carrying risk genotypes at both loci in comparison with the reference group, which had no risk genotypes. This study provides suggestive evidence that DLGAP3 and its interactive effect with SLC1A1 might be involved in susceptibility to developing OC symptoms in schizophrenia patients receiving AAP treatment.

Polymorphism of the tryptophan hydroxylase 2 (TPH2) gene is associated with chimpanzee neuroticism

In the brain, serotonin production is controlled by tryptophan hydroxylase 2 (TPH2), a genotype. Previous studies found that mutations on the TPH2 locus in humans were associated with depression and studies of mice and studies of rhesus macaques have shown that the TPH2 locus was involved with aggressive behavior. We previously reported a functional single nucleotide polymorphism (SNP) in the form of an amino acid substitution, Q468R, in the chimpanzee TPH2 gene coding region. In the present study we tested whether this SNP was associated with neuroticism in captive and wild-born chimpanzees living in Japan and Guinea, respectively. Even after correcting for multiple tests (Bonferroni p = 0.05/6 = 0.008), Q468R was significantly related to higher neuroticism (β = 0.372, p = 0.005). This study is the first to identify a genotype linked to a personality trait in chimpanzees. In light of the prior studies on humans, mice, and rhesus macaques, these findings suggest that the relationship between neuroticism and TPH2 has deep phylogenetic roots.

Platelet [³H] paroxetine binding in female patients with borderline personality disorder and their sisters

Paroxetine binding could be a vulnerability marker for traits associated with borderline personality disorder (BPD). To study this relationship, we examined [³H] paroxetine binding in female patients with BPD and their sisters. The sample consisted of 54 sibling pairs in which a proband met criteria for BPD. All subjects were given the Diagnostic Interview for Borderlines, revised (DIB-R), the Diagnostic Assessment for Personality Pathology: Brief Questionnaire (DAPP-BQ), the Barratt Impulsivity Scale (BIS), the Affective Lability Scale (ALS), the Hamilton Rating Scale for Anxiety (HAM-A), the Hamilton Rating Scale for Depression (HAM-D), and the Symptom Checklist-90, revised (SCL-90-R). All subjects had platelets assayed for [³H] paroxetine binding. There were no significant differences between probands and sisters, but both groups scored significantly lower than a previously studied control group on B(max). There were no differences on Kd. Neither B(max) nor K(d) was related to most trait or symptomatic measures. Paroxetine binding could reflect endophenotypes common to BPD probands and their first-degree relatives.

The neurochemistry of human aggression

Various data from scientific research studies conducted over the past three decades suggest that central neurotransmitters play a key role in the modulation of aggression in all mammalian species, including humans. Specific neurotransmitter systems involved in mammalian aggression include serotonin, dopamine, norepinephrine, GABA, and neuropeptides such as vasopressin and oxytocin. Neurotransmitters not only help to execute basic behavioral components but also serve to modulate these preexisting behavioral states by amplifying or reducing their effects. This chapter reviews the currently available data to present a contemporary view of how central neurotransmitters influence the vulnerability for aggressive behavior and/or initiation of aggressive behavior in social situations. Data reviewed in this chapter include emoiric information from neurochemical, pharmaco-challenge, molecular genetic and neuroimaging studies.

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.

The catechol o-methyltransferase (COMT) val(158)met polymorphism modulates the association of serious life events (SLE) and impulsive aggression in female patients with borderline personality disorder (BPD)

OBJECTIVE

We analyzed i) the effects of serious life events (SLE) on impulsive aggression, and ii) modulating effects of the COMT Val(158)Met polymorphism on the association between SLEs and impulsive aggression in borderline personality disorder (BPD).

METHOD

One hundred and twelve female BPD patients from Germany were included in this study. Impulsive aggression was assessed by the Buss-Durkee-Hostility Inventory (BDHI).

RESULTS

Childhood sexual abuse was associated with lower BDHI sum score (P = 0.003). In COMT Val(158)Val carriers, but not in Val/Met and Met/Met carriers, childhood sexual abuse and the cumulative number of SLEs were associated with lower BDHI sum scores (P < 0.05).

CONCLUSION

This study analyzing a specific gene x environment interaction in female BPD patients suggests an association between SLEs and impulsive aggression, as well as a modulating effect of the COMT Val(158)Val genotype on the relation between SLEs and impulsive aggression.

Association between dopaminergic polymorphisms and borderline personality traits among at-risk young adults and psychiatric inpatients

BACKGROUND

In the development of borderline personality disorder (BPD) both genetic and environmental factors have important roles. The characteristic affective disturbance and impulsive aggression are linked to imbalances in the central serotonin system, and most of the genetic association studies focused on serotonergic candidate genes. However, the efficacy of dopamine D2 receptor (DRD2) blocking antipsychotic drugs in BPD treatment also suggests involvement of the dopamine system in the neurobiology of BPD.

METHODS

In the present study we tested the dopamine dysfunction hypothesis of impulsive self- and other-damaging behaviors: borderline and antisocial traits were assessed by Structured Clinical Interview for Diagnosis (SCID) for DSM-IV in a community-based US sample of 99 young adults from low-to-moderate income families. For the BPD trait analyses a second, independent group was used consisting of 136 Hungarian patients with bipolar or major depressive disorder filling out self-report SCID-II Screen questionnaire. In the genetic association analyses the previously indicated polymorphisms of the catechol-O-methyl-transferase (COMT Val158Met) and dopamine transporter (DAT1 40 bp VNTR) were studied. In addition, candidate polymorphisms of the DRD2 and DRD4 dopamine receptor genes were selected from the impulsive behavior literature.

RESULTS

The DRD2 TaqI B1-allele and A1-allele were associated with borderline traits in the young adult sample (p = 0.001, and p = 0.005, respectively). Also, the DRD4 -616 CC genotype appeared as a risk factor (p = 0.02). With severity of abuse accounted for in the model, genetic effects of the DRD2 and DRD4 polymorphisms were still significant (DRD2 TaqIB: p = 0.001, DRD2 TaqIA: p = 0.008, DRD4 -616 C/G: p = 0.002). Only the DRD4 promoter finding was replicated in the independent sample of psychiatric inpatients (p = 0.007). No association was found with the COMT and DAT1 polymorphisms.

CONCLUSIONS

Our results of the two independent samples suggest a possible involvement of the DRD4 -616 C/G promoter variant in the development of BPD traits. In addition, an association of the DRD2 genetic polymorphisms with impulsive self-damaging behaviors was also demonstrated.

Variants of the serotonin transporter gene and NEO-PI-R Neuroticism: No association in the BLSA and SardiNIA samples

The polymorphism in the serotonin transporter gene promoter region (5-HTTLPR) is by far the most studied variant hypothesized to influence Neuroticism-related personality traits. The results of previous studies have been mixed and appear moderated by the personality questionnaire used. Studies that used the TCI to assess Harm Avoidance or the EPQ to assess Neuroticism have found no association with the 5-HTTLPR. However, studies that used the NEO-PI-R or related instruments (NEO-PI, NEO-FFI) to measure Neuroticism have found some evidence of association. This study examines the association of variants in the serotonin transporter gene in a sample from a genetically isolated population within Sardinia (Italy) that is several times larger than previous samples that used the NEO-PI-R (N = 3,913). The association was also tested in a sample (N = 548) from the Baltimore Longitudinal Study of Aging (BLSA), in which repeated NEO-PI-R assessments were obtained. In the SardiNIA sample, we found no significant association of the 5-HTTLPR genotypes with Neuroticism or its facets (Anxiety, Angry-Hostility, Depression, Self-Consciousness, Impulsiveness, and Vulnerability). In the BLSA sample, we found lower scores on Neuroticism traits for the heterozygous group, which is inconsistent with previous studies. We also examined eight SNPs in the SardiNIA (N = 3,972) and nine SNPs in the BLSA (N = 1,182) that map within or near the serotonin transporter gene (SLC6A4), and found no association. Along with other large studies that used different phenotypic measures and found no association, this study substantially increases the evidence against a link between 5-HTT variants and Neuroticism-related traits.