Personality disorder
A personality disorder is a mental disorder characterized by an enduring and pervasive maladaptive pattern of behavior, emotions, cognition, and inner experience, deviating from social norms. As a common feature, this manifests in significant impairment in interpersonal relationships and various aspects of functioning of the self, such as self-concept, in conjunction with pathological personality traits. These patterns develop early, are inflexible, and are associated with significant distress or disability.
Official criteria for diagnosing personality disorders are listed in the sixth chapter of the International Classification of Diseases and in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. The definitions vary by source and remain a matter of controversy. For psychiatric patients, the prevalence of personality disorders is estimated between 40 and 60%. The behavior patterns of personality disorders are typically recognized by adolescence, the beginning of adulthood or sometimes even childhood and often have a pervasive negative impact on the quality of life.
Treatment for personality disorders is primarily psychotherapeutic. Evidence-based psychotherapies for personality disorders include cognitive behavioral therapy and dialectical behavior therapy, especially for borderline personality disorder. A variety of psychoanalytic approaches are also used. Personality disorders are associated with considerable stigma in popular and clinical discourse alike. Despite various methodological schemas designed to categorize personality disorders, many issues occur with classifying a personality disorder because the theory and diagnosis of such disorders occur within prevailing cultural expectations; thus, their validity is contested by some experts on the basis of inevitable subjectivity. They argue that the theory and diagnosis of personality disorders are based strictly on social, or even sociopolitical and economic considerations.
Classification
There are two main approaches – the dimensional and the categorical – to the classification of personality disorders, which occurs mainly in accordance with the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders. The categorical approach views personality disorders as discrete entities that are distinct from each other as well as from normal personality. In contrast, the dimensional approach to personality disorders suggests that personality disorders exist on a continuum, with traits varying in degree rather than kind. The DSM-5-TR standard model is an example of the former, while the ICD-11 implements the latter.There has been a sustained movement toward replacing categorical models of personality disorder classification with dimensional approaches. The categorical model has been criticized for not being sufficiently evidence-based; for issues such as undue prevalence of comorbidity, with the majority of people with a PD being eligible for another PD diagnosis; as well as for heterogeneity within categories, and stigmatization. In response, dimensional models have been developed that assess personality disorders in terms of severity of impairment and maladaptive personality traits. Emerging research indicates that dimensional models may have the benefit of facilitating the personalization of psychotherapy by aligning treatment strategies with underlying trait dimensions rather than diagnostic categories. The shift towards a dimensional approach is reflected in the inclusion of the AMPD in Section III of the DSM-5, and in the ICD-11's adoption of a dimensional system.
DSM-5
In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, a categorical classification was retained for personality disorders. Located in Section II, personality disorders are thus listed in the same way as other mental disorders, rather than on a separate 'axis', as previously. Its ten specific personality disorders are grouped into three clusters, namely: cluster A, cluster B, and cluster C. It also contains three diagnoses for other personality disorders. The clusters are based on descriptive similarity between the disorders they encompass, and it is not proven that they possess clinical utility.DSM-5 Alternative model
Introduced in section III of the DSM-5, the Alternative DSM-5 Model for Personality Disorders is a dimensional–categorical hybrid, yielding diagnoses based on combinations of impairment in personality functioning, rated across identity, self-direction, empathy and intimacy; and pathological personality traits from the following trait domains: Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism. The AMPD includes six specific personality disorders, which are defined by specific combinations of criteria A and B; these are: antisocial, avoidant, borderline, narcissistic, obsessive-compulsive, and schizotypal. There is also a diagnosis of personality disorder–trait specified available for cases not matching the aforementioned categories. Created with the aim of ameliorating issues such as arbitrary thresholds and excessive comorbidity, the AMPD was intended to replace the categorical model in the at the time upcoming DSM-5; however, upon its rejection, it was instead placed in Section III.ICD-11
The ICD-11 classification of personality disorders is an implementation of a dimensional model, classifying a unified personality disorder as mild, moderate, severe, or severity unspecified; this being determined by the level of distress experienced and degree of impairment in day-to-day activities as a result of difficulties in aspects of self-functioning and interpersonal relationships, as well as behavioral, cognitive, and emotional dysfunctions. There is also an additional category called personality difficulty, which can be used to describe personality traits that are problematic, but do not meet the diagnostic criteria for a PD. A personality disorder or difficulty can be specified by one or more of the following prominent personality traits or patterns : Negative affectivity, Detachment, Dissociality, Disinhibition, and Anankastia. In addition to the traits, a Borderline pattern ''– similar in nature to borderline personality disorder – may be specified. In contrast to the DSM-5, the ICD-11 classifies schizotypal disorder'' among primary psychotic disorders rather than as a personality disorder.Other and historical classifications
Other types of personality disorder have been included in previous versions of the diagnostic manuals but have not been retained in subsequent editions. Examples include sadistic, self-defeating, passive–aggressive, haltlose, and immature personality disorders. As some presentations do not align with predefined categories, there are categories available for other and unspecified personality disorders in both the DSM-5-TR and preceding editions; this was also the case in the ICD-10 classification of personality disorders. Such diagnoses could be applied to the types of personality disorder which were not included as distinct categories, such as the aforementioned ones. Psychologist Theodore Millon, a researcher on personality disorders, as well as other researchers, consider some relegated diagnoses to be equally valid disorders. Millon has also proposed other personality disorders or subtypes, including mixtures of aspects of different categories of the officially accepted diagnoses.Signs and symptoms
The central features of personality disturbance in ICD-11, as in DSM-5, are disturbances in aspects of both self and interpersonal functioning. For a diagnosis, these disturbances must be enduring – so present for a minimum of two years. Self-dysfunction may manifest as persistent difficulties in maintaining a stable sense of identity, a pervasive sense of impoverished or highly over-valued self-worth, inaccuracies in self-perception or challenges in self-direction and decision making. Persistent difficulties in making and sustaining close relationships or in the ability to understand other people’s perspectives are typical manifestations of the interpersonal dysfunction. Managing conflict in relationships may also present significant challenges. These two main features will manifest in maladaptive patterns of cognition, emotional experience and expression and behaviour which must be evident across a range or personal and social situations.Causes
Personality disorders are complex conditions influenced by a combination of genetic, environmental, and experiential factors. These disorders emerge from the interaction of multiple determinants, making the precise causes difficult to identify. Environmental factors play a significant role in the development of personality disorders. These include prenatal conditions, childhood trauma, abuse, neglect, and other adverse childhood experiences. Possible genetic and neurobiological causes have also been identified.The causality can be categorized as follows: necessary causes, which are factors that must precede another event for it to occur but are not sufficient by themselves to cause the disorder; sufficient causes, which are capable of causing pathology on their own without requiring the presence of other factors to result in the development of a disorder; and contributory causes, which increase the likelihood of developing a disorder but are neither necessary nor sufficient on their own. Socioeconomic factors, childhood trauma, or other adverse life events may contribute to the emergence of a personality disorder but are not definitive causes.
The problem of genetic confounding is explained by psychologist Svenn Torgersen in a 2009 review:
Twin studies allow scientists to assess the influence of genes and environment, in particular, how much of the variation in a trait is attributed to the "shared environment" or the "unshared environment".