DSM-5 Borderline personality disorder: At the border between a dimensional and a categorical view.

Recently, the DSM-5 Personality Disorders Workgroup offered its proposed revision for borderline personality disorder (BPD) and other personality disorder types ( http://www.dsm5.org ). According to the workgroup, this revision reflects an attempt to address excessive comorbidity among personality disorders, place personality pathology on continua, and replace individual behavioral criteria with personality traits. Essentially, the committee proposes a hybrid model of BPD (ie, categorical and dimensional)-one that combines the notion of a borderline "type" with supplemental dimensional ratings of relevant personality traits. In this article, we review recent findings on the dimensionality of BPD from phenotypic, genetic, and endophenotypic perspectives. Finally, we evaluate the current DSM-5 proposal for diagnosing BPD-one that ostensibly combines a categorical and dimensional perspective-in light of these findings.

ADHD in Dutch adults: heritability and linkage study.

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental phenotype that persists into adulthood. This study investigated the heritability of inattentive and hyperactive symptoms and of total ADHD symptomatology load (ADHD index) in adults and performed linkage scans for these dimensions. Data on sibling pairs and their family members from the Netherlands Twin Register with genotype and phenotype data for inattention, hyperactivity and ADHD index (∼750 sib-pairs) were analyzed. Phenotypes were assessed with the short self-report form of the Conners' Adult ADHD Rating Scales (CAARS). Heritabilities were estimated in SOLAR under polygenic models. Genome-wide linkage scans were performed using variance components (VC) in MERLIN and MINX and model-based linkage analysis was carried out in MENDEL with empirical evaluation of the results via simulations. Heritability estimates for inattention, hyperactivity and ADHD index were 35%, 23%, and 31%, respectively. Chromosomes 18q21.31-18q21.32 (VC LOD = 4.58, p(emp) = 0.0026) and 2p25.1 (LOD = 3.58, p(emp) = 0.0372) provided significant evidence for linkage for inattention and the ADHD index, respectively. The QTL on chromosome 2p25.1 also showed suggestive linkage for hyperactivity. Two additional suggestive QTLs for hyperactivity and the ADHD index shared the same location on chromosome 3p24.3-3p24.1. Finally, a suggestive QTL on 8p23.3-8p23.2 for hyperactivity was also found. Heritability of inattention, hyperactivity and total ADHD symptoms is lower in adults than in children. Chromosomes 18q and 2p are likely to harbor genes that influence several aspects of adult ADHD.

Borderline personality traits and adult attention-deficit hyperactivity disorder symptoms: a genetic analysis of comorbidity.

Previous research has established the comorbidity of adult Attention-Deficit Hyperactivity Disorder (ADHD) with different personality disorders including Borderline Personality Disorder (BPD). The association between adult ADHD and BPD has primarily been investigated at the phenotypic level and not yet at the genetic level. The present study investigates the genetic and environmental contributions to the association between borderline personality traits (BPT) and ADHD symptoms in a sample of 7,233 twins and siblings (aged 18-90 years) registered with the Netherlands Twin Register and the East Flanders Prospective Twin Survey (EFPTS) . Participants completed the Conners' Adult ADHD Rating Scales (CAARS-S:SV) and the Personality Assessment Inventory-Borderline Features Scale (PAI-BOR). A bivariate genetic analysis was performed to determine the extent to which genetic and environmental factors influence variation in BPT and ADHD symptoms and the covariance between them. The heritability of BPT and ADHD symptoms was estimated at 45 and 36%, respectively. The remaining variance in BPT and ADHD symptoms was explained by unique environmental influences. The phenotypic correlation between BPT and ADHD symptoms was estimated at r = 0.59, and could be explained for 49% by genetic factors and 51% by environmental factors. The genetic and environmental correlations between BPT and ADHD symptoms were 0.72 and 0.51, respectively. The shared etiology between BPT and ADHD symptoms is thus a likely cause for the comorbidity of the two disorders.

Familial resemblance for loneliness.

Social isolation and loneliness in humans have been associated with physical and psychological morbidity, as well as mortality. This study aimed to assess the etiology of individual differences in feelings of loneliness. The genetic architecture of loneliness was explored in an extended twin-family design including 8,683 twins, siblings and parents from 3,911 families. In addition, 917 spouses of twins participated. The presence of assortative mating, genetic non-additivity, vertical cultural transmission, genotype-environment (GE) correlation and interaction was modeled. GE interaction was considered for several demographic characteristics. Results showed non-random mating for loneliness. We confirmed that loneliness is moderately heritable, with a significant contribution of non-additive genetic variation. There were no effects of vertical cultural transmission. With respect to demographic characteristics, results indicated that marriage, having offspring, more years of education, and a higher number of siblings are associated with lower levels of loneliness. Interestingly, these effects tended to be stronger for men than women. There was little evidence of changes in genetic architecture as a function of these characteristics. We conclude that the genetic architecture of loneliness points to non-additive genetic influences, suggesting it may be a trait that was not neutral to selection in our evolutionary past. Sociodemographic factors that influence the prevalence of loneliness do not affect its genetic architecture.

Migraine symptomatology and major depressive disorder.

INTRODUCTION AND OBJECTIVE: Migraine and major depressive disorder (MDD) frequently co-occur, but it is unclear whether depression is associated with a specific subtype of migraine. The objective of this study was to investigate whether migraine is qualitatively different in MDD patients (N = 1816) and non-depressed controls (N = 3428). METHODS: Migraine symptom data were analyzed using multi-group Latent Class Analysis, and a qualitative comparison was made between the symptom profiles of MDD patients and controls, while allowing for differences in migraine prevalence and severity between groups. RESULTS: In both groups, three migrainous headache classes were identified, which differed primarily in terms of severity. Both mild and severe migrainous headaches were two to three times more prevalent in MDD patients. Migraine symptom profiles showed only minor qualitative differences in the MDD and non-MDD groups: in the severe migrainous headache class, significant differences were observed only in the prevalence of aggravation by physical activity (83% and 91% for the non-MDD and MDD groups, respectively) and aura (42% vs. 53%, respectively). CONCLUSION: The similar overall symptom profiles observed in the MDD and non-MDD subjects suggest that a similar disease process may underlie migraine in both groups.

Assessment of borderline personality features in population samples: is the Personality Assessment Inventory-Borderline Features scale measurement invariant across sex and age?

Borderline personality disorder (BPD) is more often diagnosed in women than in men, and symptoms tend to decline with age. Using a large community sample, the authors investigated whether sex and age differences in four main features of BPD, measured with the Personality Assessment Inventory-Borderline Features scale (PAI-BOR; Morey, 1991), are a result of measurement bias or if they represent true differences. The PAI-BOR was completed by four Sex x Age groups (N = 6,838). Multigroup confirmatory factor analysis showed that the PAI-BOR is measurement invariant across sex and age. Compared with men, women reported more borderline characteristics for affective instability, identity problems, and negative relationships but not for self-harm. Younger men had higher scores for identity problems and self-harm than did older men. Younger women had higher scores for identity problems and affective instability than did older women. Results suggest that the PAI-BOR can be used to study the etiology of BPD features in population-based samples and to screen for BPD features in clinical settings in both men and women of varying ages. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

A genome-wide linkage scan provides evidence for both new and previously reported loci influencing common migraine.

Latent class analysis was performed on migraine symptom data collected in a Dutch population sample (N = 12,210, 59% female) in order to obtain empirical groupings of individuals suffering from symptoms of migraine headache. Based on these heritable groupings (h(2) = 0.49, 95% CI: 0.41-0.57) individuals were classified as affected (migrainous headache) or unaffected. Genome-wide linkage analysis was performed using genotype data from 105 families with at least 2 affected siblings. In addition to this primary phenotype, linkage analyses were performed for the individual migraine symptoms. Significance levels, corrected for the analysis of multiple traits, were determined empirically via a novel simulation approach. Suggestive linkage for migrainous headache was found on chromosomes 1 (LOD = 1.63; pointwise P = 0.0031), 13 (LOD = 1.63; P = 0.0031), and 20 (LOD = 1.85; P = 0.0018). Interestingly, the chromosome 1 peak was located close to the ATP1A2 gene, associated with familial hemiplegic migraine type 2 (FHM2). Individual symptom analysis produced a LOD score of 1.97 (P = 0.0013) on chromosome 5 (photo/phonophobia), a LOD score of 2.13 (P = 0.0009) on chromosome 10 (moderate/severe pain intensity) and a near significant LOD score of 3.31 (P = 0.00005) on chromosome 13 (pulsating headache). These peaks were all located near regions previously reported in migraine linkage studies. Our results provide important replication and support for the presence of migraine susceptibility genes within these regions, and further support the utility of an LCA-based phenotyping approach and analysis of individual symptoms in migraine genetic research. Additionally, our novel "2-step" analysis and simulation approach provides a powerful means to investigate linkage to individual trait components.

Personality, health and lifestyle in a questionnaire family study: a comparison between highly cooperative and less cooperative families.

The effect of nonresponse on health and lifestyle measures has received extensive study, showing at most relatively modest effects. Nonresponse bias with respect to personality has been less thoroughly investigated. The present study uses data from responding individuals as a proxy for the missing data of their nonresponding family members to examine the presence of nonresponse bias for personality traits and disorders as well as health and lifestyle traits. We looked at the Big Five personality traits, borderline personality disorder (BPD) features, attention-deficit/hyperactivity disorder, Anger, and several measures of health (Body Mass Index, migraine) and lifestyle (smoking, alcohol use). In general, outcomes tend to be slightly more favorable for individuals from highly cooperative families compared to individuals from less cooperative families. The only significant difference was found for BPD features (p = .001). However, the absolute difference in mean scores is very small, less than 1 point for a scale ranging from 0 to 72. In conclusion, survey data on personality, health and lifestyle are relatively unbiased with respect to nonresponse.

Netherlands Twin Register: from twins to twin families.

In the late 1980s The Netherlands Twin Register (NTR) was established by recruiting young twins and multiples at birth and by approaching adolescent and young adult twins through city councils. The Adult NTR (ANTR) includes twins, their parents, siblings, spouses and their adult offspring. The number of participants in the ANTR who take part in survey and / or laboratory studies is over 22,000 subjects. A special group of participants consists of sisters who are mothers of twins. In the Young NTR (YNTR), data on more than 50,000 young twins have been collected. Currently we are extending the YNTR by including siblings of twins. Participants in YNTR and ANTR have been phenotyped every 2 to 3 years in longitudinal survey studies, since 1986 and 1991 for the YNTR and ANTR, respectively. The resulting large population-based datasets are used for genetic epidemiological studies and also, for example, to advance phenotyping through the development of new syndrome scales based on existing items from other inventories. New research developments further include brain imaging studies in selected and unselected groups, clinical assessment of psychopathology through interviews, and cross-referencing the NTR database to other national databases. A large biobank enterprise is ongoing in the ANTR in which blood and urine samples are collected for genotyping, expression analysis, and metabolomics studies. In this paper we give an update on the YNTR and ANTR phenotyping and on the ongoing ANTR biobank studies.

Borderline personality features in depressed or anxious patients.

Anxiety and depression frequently co-occur with borderline personality disorder. Relatively little research examined the presence of borderline personality features and its main domains (affective instability, identity problems, negative relationships and self-harm) in individuals with remitted and current anxiety and depression. Participants with current (n=597) or remitted (n=1115) anxiety and/or depression and healthy controls (n=431) were selected from the Netherlands Study of Depression and Anxiety. Assessments included the Personality Assessment Inventory - Borderline Features Scale and several clinical characteristics of anxiety and depression. Borderline personality features were more common in depression than in anxiety. Current comorbid anxiety and depression was associated with most borderline personality features. Anxiety and depression status explained 29.7% of the variance in borderline personality features and 3.8% (self-harm) to 31% (identity problems) of the variance in the four domains. A large part of the variance was shared between anxiety and depression but both disorders also explained a significant amount of unique variance. The severity of anxiety and depression and the level of daily dysfunctioning was positively associated with borderline personality features. Individuals with a longer duration of anxiety and depression showed more affective instability and identity problems. These findings suggest that patients with anxiety and depression may benefit from an assessment of personality pathology as it may have implications for psychological and pharmacological treatment.

The covariation of trait anger and borderline personality: a bivariate twin-siblings study.

Anger can be defined as an emotion consisting of feelings of variable intensity, from mild irritation or annoyance to intense fury and rage. Borderline personality disorder (BPD) is characterized by impulsivity and instability of interpersonal relationships, of self-image, and of negative affects. Borderline personality and trait anger are often observed together. The present study examined the extent to which a genetic association explains the covariation between a trait measure of borderline personality and trait anger. To this end, self-report data of 5,457 twins and 1,487 of their siblings registered with the Netherlands Twin Register and the East Flanders Prospective Twin Survey were analyzed using genetic structural equation modeling. A significant phenotypic correlation was observed between the two traits (rP = .52). This correlation was explained by genetic (54%) and by environmental influences (46%). A shared genetic risk factor is thus one of the explanations for the covariation of borderline personality and trait anger.

Borderline personality traits and substance use: genetic factors underlie the association with smoking and ever use of cannabis, but not with high alcohol consumption.

Borderline personality disorder (BPD) and substance use disorders often co-occur. Both disorders are heritable and family studies showed that there are familial factors that increase the risk for BPD as well as substance use/abuse. This is the first study that investigates whether the association of borderline personality traits (BPT) with substance use reflects an underlying genetic vulnerability or nongenetic familial influences. To this end we analyzed data of 5,638 Dutch and Belgian twins aged between 21-50 years from 3,567 families. Significant associations between BPT and high alcohol consumption (r = .192), regular smoking (r = .299), and ever use of cannabis (r = .254) were found. Bivariate genetic analyses showed that the associations of BPT and substance use had different etiologies. For regular smoking and for ever use of cannabis, the correlation with BPT was explained by common genetic factors. Interestingly, for high alcohol consumption and BPT the association was explained by unique environmental factors that influence both traits rather than common genetic factors.

Sex differences in genetic architecture of complex phenotypes?

We examined sex differences in familial resemblance for a broad range of behavioral, psychiatric and health related phenotypes (122 complex traits) in children and adults. There is a renewed interest in the importance of genotype by sex interaction in, for example, genome-wide association (GWA) studies of complex phenotypes. If different genes play a role across sex, GWA studies should consider the effect of genetic variants separately in men and women, which affects statistical power. Twin and family studies offer an opportunity to compare resemblance between opposite-sex family members to the resemblance between same-sex relatives, thereby presenting a test of quantitative and qualitative sex differences in the genetic architecture of complex traits. We analyzed data on lifestyle, personality, psychiatric disorder, health, growth, development and metabolic traits in dizygotic (DZ) same-sex and opposite-sex twins, as these siblings are perfectly matched for age and prenatal exposures. Sample size varied from slightly over 300 subjects for measures of brain function such as EEG power to over 30,000 subjects for childhood psychopathology and birth weight. For most phenotypes, sample sizes were large, with an average sample size of 9027 individuals. By testing whether the resemblance in DZ opposite-sex pairs is the same as in DZ same-sex pairs, we obtain evidence for genetic qualitative sex-differences in the genetic architecture of complex traits for 4% of phenotypes. We conclude that for most traits that were examined, the current evidence is that same the genes are operating in men and women.

Age moderates non-genetic influences on the initiation of cannabis use: a twin-sibling study in Dutch adolescents and young adults.

AIMS: To examine the heritability of cannabis initiation, the influence of a possible twin-specific environment and the influence of age on the effects of genes and environment in Dutch adolescents and young adults. DESIGN: Genetic structural equation modelling was used to partition the variance in the liability to cannabis initiation into genetic and environmental components. SETTING: All participants were registered with the Netherlands Twin Register. PARTICIPANTS: A total of 6,208 twins (age 13-20) and 1,545 siblings (age 11-25) from 3,503 families participated in this study. MEASUREMENTS: Self-reported cannabis use was assessed prospectively with the Dutch Health Behavior Questionnaire. FINDINGS: At the median age of the sample (16.5), genetic factors explained 40% of the individual differences in liability to cannabis initiation. Twins resembled each other more than non-twin siblings, which could not be attributed to the age difference between non-twin siblings. Environmental influences increased with age. This increase applied to environmental factors shared by twins (47% of the variance), environmental factors shared by twins and siblings (24%) and environmental factors unique to an individual (13%). CONCLUSION: The heritability of the liability for cannabis initiation is higher in adolescents than in young adults due to a larger contribution of environmental factors in young adults. This is due mainly to environmental factors only shared by twins and those shared by all offspring growing up in the same family, but the contribution of environmental factors specific to individuals is also larger in young adults.

Genetic covariance structure of the four main features of borderline personality disorder.

The patient population of borderline personality disorder (BPD) is heterogeneous; many different combinations of BPD symptoms can lead to a BPD diagnosis. We investigated to what extent the covariance among four main components of BPD is explained by shared genetic and environmental factors. Using an extended twin design, multivariate genetic models were applied to the scales of the PAI-BOR, a self-report questionnaire tapping four main features of BPD (affective instability, identity problems, negative relationships, and self-harm). Data on the four BPD scales were available for 5,533 twins and 1,202 siblings from the Netherlands, Belgium, and Australia. The correlations among the scales ranged from 0.23 to 0.50 and were best explained by a genetic common pathway model. This model specifies that genes and environment influence the covariance between four main features of BPD in qualitatively similar ways, through a single latent factor representing the BPD construct. The heritability of the latent BPD factor was 51% and the remainder of its variance was explained by unique environmental influences. For each BPD scale, except self-harm, around 50% of its variance was explained by the latent BPD factor. The remaining variance for each of the four scales was explained by genetic (4% for affective instability to 20% for self-harm) and environmental (38% for negative relationships to 67% for self-harm) factors that were specific to each scale.

Genetic epidemiology of attention deficit hyperactivity disorder (ADHD index) in adults.

CONTEXT: In contrast to the large number of studies in children, there is little information on the contribution of genetic factors to Attention Deficit Hyperactivity Disorder (ADHD) in adults. OBJECTIVE: To estimate the heritability of ADHD in adults as assessed by the ADHD index scored from the CAARS (Conners' Adult ADHD Rating Scales). DESIGN: Phenotype data from over 12,000 adults (twins, siblings and parents) registered with the Netherlands Twin Register were analyzed using genetic structural equation modeling. MAIN OUTCOME MEASURES: Heritability estimates for ADHD from the twin-family study. RESULTS: Heritability of ADHD in adults is estimated around 30% in men and women. There is some evidence for assortative mating. All familial transmission is explained by genetic inheritance, there is no support for the hypothesis that cultural transmission from parents to offspring is important. CONCLUSION: Heritability for ADHD features in adults is present, but is substantially lower than it is in children.

Familial resemblance of borderline personality disorder features: genetic or cultural transmission?

Borderline personality disorder is a severe personality disorder for which genetic research has been limited to family studies and classical twin studies. These studies indicate that genetic effects explain 35 to 45% of the variance in borderline personality disorder and borderline personality features. However, effects of non-additive (dominance) genetic factors, non-random mating and cultural transmission have generally not been explored. In the present study an extended twin-family design was applied to self-report data of twins (N = 5,017) and their siblings (N = 1,266), parents (N = 3,064) and spouses (N = 939) from 4,015 families, to estimate the effects of additive and non-additive genetic and environmental factors, cultural transmission and non-random mating on individual differences in borderline personality features. Results showed that resemblance among biological relatives could completely be attributed to genetic effects. Variation in borderline personality features was explained by additive genetic (21%; 95% CI 17-26%) and dominant genetic (24%; 95% CI 17-31%) factors. Environmental influences (55%; 95% CI 51-60%) explained the remaining variance. Significant resemblance between spouses was observed, which was best explained by phenotypic assortative mating, but it had only a small effect on the genetic variance (1% of the total variance). There was no effect of cultural transmission from parents to offspring.

The five-factor model of personality and borderline personality disorder: a genetic analysis of comorbidity.

BACKGROUND: Recently, the nature of personality disorders and their relationship with normal personality traits has received extensive attention. The five-factor model (FFM) of personality, consisting of the personality traits neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness, is one of the proposed models to conceptualize personality disorders as maladaptive variants of continuously distributed personality traits. METHODS: The present study examined the phenotypic and genetic association between borderline personality and FFM personality traits. Data were available for 4403 monozygotic twins, 4425 dizygotic twins, and 1661 siblings from 6140 Dutch, Belgian, and Australian families. RESULTS: Broad-sense heritability estimates for neuroticism, agreeableness, conscientiousness, extraversion, openness to experience, and borderline personality were 43%, 36%, 43%, 47%, 54%, and 45%, respectively. Phenotypic correlations between borderline personality and the FFM personality traits ranged from .06 for openness to experience to .68 for neuroticism. Multiple regression analyses showed that a combination of high neuroticism and low agreeableness best predicted borderline personality. Multivariate genetic analyses showed the genetic factors that influence individual differences in neuroticism, agreeableness, conscientiousness, and extraversion account for all genetic liability to borderline personality. Unique environmental effects on borderline personality, however, were not completely shared with those for the FFM traits (33% is unique to borderline personality). CONCLUSIONS: Borderline personality shares all genetic variation with neuroticism, agreeableness, conscientiousness, and extraversion. The unique environmental influences specific to borderline personality may cause individuals with a specific pattern of personality traits to cross a threshold and develop borderline personality.

Chromosome 9: linkage for borderline personality disorder features.

OBJECTIVE: A large-scale twin study implicated genetic influences on borderline personality disorder (BPD) features, with a heritability estimate of 42%. To date, no genome-wide linkage study has been conducted to identify the genomic region(s) containing the quantitative trait loci that influence the manifestation of BPD features. METHODS: We conducted a family-based linkage study using Merlin regress. The participating families were drawn from the community-based Netherlands Twin Register. The sample consisted of 711 sibling pairs with phenotype and genotype data, and 561 additional parents with genotype data. BPD features were assessed on a quantitative scale. RESULTS: Evidence for linkage was found on chromosomes 1, 4, 9, and 18. The highest linkage peak was found on chromosome 9p at marker D9S286 with a logarithm of odds score of 3.548 (empirical P=0.0001). CONCLUSION: To our knowledge, this is the first linkage study on BPD features and shows that chromosome 9 is the richest candidate for genes influencing BPD. The results of this study will move the field closer to determining the genetic etiology of BPD and may have important implications for treatment programs in the future. Association studies in this region are, however, warranted to detect the actual genes.

Heritability of self-reported phobic fear.

Twin studies on fear and phobia suggest moderate genetic effects. However, results are inconclusive regarding the presence of dominant genetic effects and sex differences. Using an extended twin design, including male and female twins (n = 5,465) and their siblings (n = 1,624), we examined the genetic and environmental influences on blood-injury, social, and agoraphobic fear and investigated their interaction with sex and age. Data of spouses (n = 708) of twins were used to evaluate assortative mating for the three fear dimensions. Results showed that there was no assortative mating for blood-injury, social and agoraphobic fear. Resemblance between biological relatives could be explained by additive and non-additive genetic effects for blood-injury and agoraphobic fear in all participants, and social fear in participants aged 14-25 years. For social fear in participants aged 26-65 only additive genetic effects were detected. Broad-sense heritability estimates ranged from 36 to 51% and were similar for men and women.