The relationship between avoidant personality disorder and social phobia: a population-based twin study

OBJECTIVE: The purpose of this study was to determine the sources of comorbidity for social phobia and dimensional representations of avoidant personality disorder by estimating to what extent the two disorders are influenced by common genetic and shared or unique environmental factors versus the extent to which these factors are specific to each disorder. METHOD: Young adult female-female twin pairs (N=1,427) from the Norwegian Institute of Public Health Twin Panel were assessed at personal interview for avoidant personality disorder and social phobia using the Structured Interview for DSM-IV Personality and the Composite International Diagnostic Interview. Bivariate Cholesky models were fitted using the Mx statistical program. RESULTS: The best-fitting model included additive genetic and unique environmental factors only. Avoidant personality disorder and social phobia were influenced by the same genetic factors, whereas the environmental factors influencing the two disorders were uncorrelated. CONCLUSIONS: Within the limits of statistical power, these results suggest that there is a common genetic vulnerability to avoidant personality disorder and social phobia in women. An individual with high genetic liability will develop avoidant personality disorder versus social phobia entirely as a result of the environmental risk factors unique to each disorder. The results are in accordance with the hypothesis that psychobiological dimensions span the axis I and axis II disorders.     

Do the dimensions of the temperament and character inventory map a simple genetic architecture? Evidence from molecular genetics and factor analysis

OBJECTIVE: It has been reported that the human temperament dimensions of novelty seeking and harm avoidance are associated with polymorphisms in the D(4) dopamine receptor gene (D4DR) and the serotonin-transporter-linked promoter region (5-HTTLPR), respectively. Although these findings are consistent with Cloninger's hypothesized psychobiological model of temperament and character, many studies failed to replicate these findings. In the present study the authors tested whether the psychobiological model taps the genetic architecture of personality by exploring associations between these candidate genes and the dimensions of the Temperament and Character Inventory and by examining its phenotypic structure. METHOD: Of the 946 male and female participants in the Baltimore Longitudinal Study of Aging to whom the Temperament and Character Inventory was administered, 587 were genotyped for a polymorphism with a 48-base-pair repeat in the D4DR gene and 425 were genotyped for a 44-base-pair insertion or deletion in the 5-HTTLPR polymorphism. RESULTS: There was no significant association between D4DR polymorphisms and novelty seeking. The authors also failed to find an association between 5-HTTLPR polymorphisms and harm avoidance. The factor structure of the Temperament and Character Inventory did not reveal the hypothesized phenotypic structure. CONCLUSIONS: This investigation produced no support for the temperament-character model at either the biological or psychological level.     

Neurogenetic and experiential processes underlying major personality traits: implications for modelling personality disorders

Abstract The association of personality traits to personality disorders (PDs) is assumed by many to fit a dimensional model, where PDs emerge at the extremes of personality dimensions. Nevertheless, attempts to demonstrate such an association have been empirically disappointing and conceptually unilluminating. In this article we attempt to extend such models by outlining the neurobehavioural systems that underlie major personality traits, and highlight the evidence that they are subject to experience-dependent modification that can be enduring through effects on genetic expression, mainly through processes known as epigenetics. It is through such processes that risk for personality disorder may be modified by experience at any point in development, but perhaps especially during early critical periods of development. We conclude by presenting a novel multidimensional model of PDs that relies on the concepts developed earlier in the article. Our goal is to provide a guide for research on the psychobiological nature and pharmacological treatment of PDs.     

Temperament and character in patients with borderline personality disorder taking gender and comorbidity into account

This study examined correlations of borderline personality disorder (BPD) symptoms with scales from Cloninger's psychobiological model taking gender and psychiatric comorbidity into consideration. Inpatients with BPD (n = 202) were compared to several control groups including psychiatrically healthy persons (n = 327), subjects with affective disorders (n = 46), alcohol use disorders (n = 47), cluster C personality disorders (n = 23) and antisocial personality disorder (n = 25). The results indicate that only males with BPD presented an 'explosive' temperament suggested by Cloninger, with simultaneously high levels of novelty seeking and harm avoidance. In contrast, women with BPD were characterized by high levels of harm avoidance, but not novelty seeking. Regarding temperament and character dimensions our analyses suggest that patients with BPD could be characterized, in particular, by a combination of high harm avoidance and very low self-directedness. The specific temperament configuration of BPD postulated by Cloninger's psychobiological model could only partially be supported. The results provide support for the importance of controlling for gender effects when investigating the applicability of dimensional models with respect to personality disorders.     

The borderline diagnosis II: biology, genetics, and clinical course.

In Part I of this three-part article, consideration of the core features of BPD psychopathology, of comorbidity with Axis I disorders, and of underlying personality trait structure suggested that the borderline diagnosis might be productively studied from the perspective of dimensions of trait expression, in addition to that of the category itself. In Part II, we review the biology, genetics, and clinical course of borderline personality disorder (BPD), continuing to attend to the utility of a focus on fundamental dimensions of psychopathology. Biological approaches to the study of personality can identify individual differences with both genetic and environmental influences. The aspects of personality disorder that are likely to have biologic correlates are those involving regulation of affects, impulse/action patterns, cognitive organization and anxiety/inhibition. For BPD, key psychobiological domains include impulsive aggression, associated with reduced serotonergic activity in the brain, and affective instability, associated with increased responsivity of cholinergic systems. There may be a strong genetic component for the development of BPD, but it seems clear, at least, that there are strong genetic influences on traits that underlie it, such as neuroticism, impulsivity, anxiousness, affective lability, and insecure attachment. The course of BPD suggests a heterogeneous disorder. Predictors of poor prognosis include history of childhood sexual abuse, early age at first psychiatric contact, chronicity of symptoms, affective instability, aggression, substance abuse, and increased comorbidity. For research purposes, at least, biological, genetic, and prognostic studies all continue to suggest the need to supplement categorical diagnoses of BPD with assessments of key underlying personality trait dimensions and with historical and clinical observations apart from those needed to make the borderline diagnosis itself.     

A psychobiological approach to personality: examination within anxious outpatients.

OBJECTIVE: To examine Cloninger's psychobiological personality model among different anxiety and depressive outpatients as well as normal healthy comparisons. In addition, the relationship between the underlying temperament dimensions and behavioral coping strategies was also studied using the tri-axial model of coping. METHODS: Subjects were 120 outpatients presenting to an anxiety disorders specialty clinic and 17 normal comparisons. They underwent a semi-structured clinical interview and completed a battery of questionnaires, including the Temperament and Character Inventory and the Strategic Approach to Coping Scale. RESULTS: On the temperament dimensions, the patients were elevated on the harm avoidance scale relative to the normal comparisons; the temperament substrate was not differentiated by the anxiety or affective diagnostic types nor was there differences between groups on the other temperament dimensions. Both severity of illness and the presence of a comorbid depressive disorder each contributed independently to harm avoidance scores. Hypotheses regarding the association between underlying temperament and behavioral coping strategies were supported for the dimensions of reward dependence and harm avoidance, but not for novelty seeking. CONCLUSIONS: Cloninger's psychobiological model is supported with the temperament of harm avoidance being the relevant dimension for anxiety and affective disorders. The underlying temperament structure also has clinical relevance for the type of coping strategies that are utilized by an individual.     

Factor validity of the temperament and character inventory in patients with major depression.

Cloninger has proposed a seven-factor psychobiological model of personality and has developed the Temperament and Character Inventory (TCI) to measure four temperament dimensions and three character dimensions. This theory of personality may be of great importance in developing an integrated understanding of psychosocial and biological processes underlying the etiology and course of depression, and a large number of studies are being carried out using the TCI to determine the pathology of depression. The present study investigated the factor validity of the TCI in 156 mildly to moderately depressed patients with major depression. The results indicate that the TCI is an internally consistent and factor-analytically valid instrument in patients. Although there was some evidence that a state of depression strengthened correlation between harm avoidance and cooperativeness, the proposed factor structure of the TCI appeared, in general, robust against the state effect of depression, when the state was mild to moderate. These results suggested that the TCI has considerable promise as an instrument for characterizing the underlying personality structure of mildly to moderately depressed patients with major depression.     

Axis II personality disorders: diagnostic and treatment issues

The placement of personality disorders on a separate axis in DSM-III reflects increased interest in their diagnosis and treatment and encourages clinicians to consider the effects of personality style on axis I clinical syndromes. In this review of axis II personality disorders, the authors discuss methodological issues related to the diagnosis of all personality disorders, review the use of various treatment modalities, and present current issues and controversies related to specific personality disorders. They urge that any revision of DSM-III incorporate more reliable and clinically meaningful criteria, perhaps substituting a multidimensional classification system for the current categorical model.     

What dimensions underlie cluster B personality disorders?

This report presents a conceptual model of the relationships between personality dimensions and the four personality disorders listed in the B cluster on axis II. The hypothesis will be developed that while impulsivity is the common dimension underlying all four disorders, differences between the categories reflect the severity of impulsive traits, interactions with other personality dimensions, the effects of gender, and the influence of culture. Clinical and research implications of the model are then described.     

Personality disorders: new data versus old concepts

PURPOSE OF REVIEW: The purpose of this paper is to review the most recent literature on personality disorders. RECENT FINDINGS: Recent data suggest that individual personality disorder criteria and full diagnosis may remit within 1-2 years. The same line of evidence disputes the separation of axis I and axis II disorders and suggests the presence of a continuum. Neuropsychological, neurobiological and genetic studies favor the presence of cognitive disorders and a non-specific mode of hereditability concerning all externalizing disorders. How to best treat personality disorders remains elusive. The most impressive news in the forensic field concerns the introduction of a new concept, dangerous and severe personality disorder by the UK government, for prevention and treatment purposes. SUMMARY: The most recent data do not adequately support a separate axis II. Future classification may need to move personality disorders to axis I, each under a suitable group of diseases and eliminate the very term 'personality' from the nomenclature, since it constitutes an empirically unsupported theoretical invasion in a system supposed to be 'atheoretical'.     

Long-term effects of adverse childhood experiences - Actual evidence and needs for research1/2

There is evidence from some prospective and several retrospective studies that early biological and psychosocial stress in childhood is associated with long-term vulnerability to various mental and physical diseases. In the last few years research findings have accumulated on those emotional, behavioural and psychobiological factors which are responsible for the mediation of these lifelong consequences. They are the cause of an increased risk of somatization and other mental disorders. Particularly anxiety, depression and personality disorders often result in high-risk behaviour that itself is associated with physical disease (cardiovascular disorders, stroke, viral hepatitis, type 2 diabetes, chronic lung diseases) as well as with aggressive behaviour. A survey on the current knowledge of how these various factors interact is presented and a bio-psychopathological model of vulnerability is educed. Implications for future research are outlined and contrasted to actual political trends in Germany.     

Hoarding in obsessive-compulsive disorder: clinical and genetic correlates

OBJECTIVE: Hoarding may be an important symptom dimension in obsessive-compulsive disorder (OCD). Hoarding in OCD has been associated with poor insight, poorer response to selective serotonin reuptake inhibitors than other OCD symptom dimensions, and a distinctive psychobiological profile. The clinical and genetic correlates of hoarding in OCD therefore deserve additional investigation. METHOD: Adult OCD patients (N = 315) underwent a comprehensive clinical assessment that included the Structured Clinical Interview for DSM-IV Axis I Disorders (Patient Edition) and for Diagnosis of Obsessive-Compulsive Spectrum Disorders. DNA extracted from venous blood (10-30 mL) in a Caucasian subset of the interviewed OCD patients (N = 204) and Caucasian controls (N = 169), including patients (N = 94) and controls (N = 138) of Afrikaner descent, was genotyped to investigate polymorphisms in genes involved in monoamine function and previously hypothesized to be relevant to OCD. Data were collected from 1998 through 2004. RESULTS: OCD patients with hoarding made up 18.1% of the total sample. Compared with nonhoarding OCD, OCD with hoarding was associated with a number of comorbid Axis I disorders, obsessive-compulsive personality disorder, significantly higher OCD severity scores, and more functional impairment. In subjects of Afrikaner descent, the L/L genotype of the COMT Val158Met polymorphism was significantly more common in the OCD hoarding group, with a preponderance of low activity alleles, compared with nonhoarding patients and controls. CONCLUSIONS: These data are consistent with the hypothesis that hoarding represents a unique symptom subtype in OCD with a distinctive clinical and psychobiological profile. Further work is needed to determine the psychobiological mechanisms responsible for hoarding and to replicate the genetic findings noted here.     

Genetics of anxiety disorders. Current clinical and molecular research

The authors give an overview of the present state of knowledge on the genetics of anxiety disorders. According to ICD-10 or DSM III/IV classification, anxiety disorders comprise panic disorder, generalized anxiety, phobias, and post-traumatic stress disorder. In the context of the conceptual change from psychodynamic anxiety neuroses to complex, multifactorial anxiety disorders, a summary of biological hypotheses of the pathogenesis of anxiety derived from pharmacotherapy, challenge tests, and animal model disorders is provided. The relevant findings from clinical genetic studies (twin and family) and molecular genetic studies (linkage and association) are presented in detail. The most data now available are on panic disorder, though with regard to molecular genetics these are still preliminary. In addition, genetic findings on anxiety as a personality dimension are reviewed, taking into account the present phenotype discussion (category vs dimension). Finally, ethical and therapeutic implications of genetic research on complex, polygenic disorders are discussed.     

Some biological and behavioral features associated with clinical personality types

The author reviews supporting evidence for the existence of two personality prototypes that correspond to two DSM-III-R personality "clusters." These hypothetical personality prototypes are characterized by extreme variations along several interrelated personality trait dimensions and by differences in two biological measures. The possibility that individual differences in central serotonin and/or catecholamine activity may underlie some of the features associated with these prototypes is discussed in light of current data. The usefulness of this conceptualization as a supplemental axis of personality classification is suggested.     

Historical comment on DSM-III schizoid and avoidant personality disorders

The authors examine the DSM-III distinction between schizoid and avoidant personality disorders. This distinction is based on Millon's biosocial learning theory and his interpretation of Kretschmer's personality types. The authors argue that this separation of a continuous distribution is historically misconceived and serves to obscure the significant features of schizoid personality. They examine Kretschmer's conceptualization of schizoid personality for the implications it carries for the development of a classification of personality disorder, suggesting that Kretschmer's approach implies a "polythetic" model of personality disorder that conceptualizes disorders as categories of dimensions.     

Temperament and character dimensions and their relationship to major depression and panic disorder

IntroductionSince the first publication of Cloninger's psychobiological model of personality, the relationship between temperament and character dimensions and psychiatric disorders has been widely studied. The exact nature of this interaction, however, is still unclear. Different models have been proposed (state-dependency, vulnerability, continuous spectrum etc).ObjectiveTo analyze the relationship between temperament and character dimensions with depression and panic disorder.MethodSystematic review on interventional studies published up until December 2011 on MEDLINE and ISI databases. Also, a brief review on genetic studies is hereby undertaken, aiming to discuss the gene-environment interaction in relation to this topic.Results:Thirteen studies were included: 10 related to depression and 3 to panic disorder (or unspecific anxiety symptoms). All of them showed association between high harm avoidance (HA) and low self-directedness (SD) with depression and anxiety symptoms. Longitudinal studies demonstrated that these traits may not be just state-dependent.Conclusions:HA and SD dimensions are associated with both the occurrence of depressive and anxiety symptoms. There is also some evidence to suggest that high HA and low SD indicates susceptibility to depression. Longitudinal studies are not sufficient to affirm the same about panic disorder up to the present moment.     

Alexithymia and temperament and character model of personality in alcohol-dependent Turkish men

Aims:  Alexithymia, a personality trait characterized as having problems identifying, describing, and working with one's own feelings, often marked by a lack of understanding of the feelings of others, is only partly described within the context of personality. The aim of the present study was therefore to study the prevalence of alexithymia among male alcohol-dependent inpatients and investigate the relationship between alexithymia and the dimensions of Cloninger's psychobiological model of personality.
Methods:  The Turkish version of the Toronto Alexithymia Scale (TAS-20) and the Turkish version of the Temperament and Character Inventory (TCI) were administered to 111 male alcohol-dependent inpatients.
Results:  TAS-20 scores correlated positively with harm avoidance and self-transcendence and negatively with self-directedness and cooperativeness. Regression analysis identified high harm avoidance and self-transcendence and low self-directedness as independent predictors of alexithymia. Also harm avoidance and self-transcendence predicted alexithymia in a logistic regression model.
Conclusions:  Alexithymia can be explained by specific dimensions within Cloninger's psychobiological model of personality in alcohol-dependent Turkish men.     

Characterizing affective instability in borderline personality disorder

OBJECTIVE: This study sought to understand affective instability among patients with borderline personality disorder by examining the degree of instability in six affective domains. The authors also examined the subjective intensity with which moods are experienced and the association between instability and intensity of affect. METHOD: In a group of 152 patients with personality disorders, subjective affective intensity and six dimensions of affective instability were measured. The mean scores for lability and intensity for each affective domain for patients with borderline personality disorder were compared with those of patients with other personality disorders through analyses that controlled for other axis I affective disorders, age, and sex. RESULTS: Greater lability in terms of anger and anxiety and oscillation between depression and anxiety, but not in terms of oscillation between depression and elation, was associated with borderline personality disorder. Contrary to expectation, the experience of an increase in subjective affective intensity was not more prominent in patients with borderline personality disorder than in those with other personality disorders. CONCLUSIONS: By applying a finer-grained perspective on affective instability than those of previous personality disorder studies, this study points to patterns of affective experience characteristic of patients with borderline personality disorder.