PERSONALITY DISORDERS IN GENERAL
The prevalence of diagnosable personality disorders in the general population has been estimated at 10–20%. This rate is much higher in mental health treatment settings, with as many as 50% of psychiatric patients meeting criteria for one or more personality disorders.
Some personality disorders are diagnosed more frequently in men, and some are more prevalent in women. Thus, for example, borderline personality disorder appears to be more common in women. Antisocial personality disorder predominates in men.
The causes of personality disorders are not well understood. As with essentially every other type of psychiatric disorder, they probably involve various combinations of biologic, temperamental, and social etiologies. Historically, classic psychoanalytic theory suggests that personality disorders occur when a person fails to progress through the usual stages of psychosexual development. Fixation in early infancy, referred to as the oral stage, is considered as contributing to a personality characterized by demanding and dependent behavior, the current parallel being the dependent personality disorder. Fixation at the stage of development focused on toilet training, in psychoanalytic terminology the anal phase, is thought to contribute to obsessionality, rigidity, and emotional aloofness. The current diagnostic parallel is obsessive–compulsive personality disorder. Fixation at early childhood, or the phallic phase, is thought to contribute to shallowness and difficulty sustaining intimate relationships, the diagnostic parallel being histrionic personality disorder.
Related to the foregoing focus, developmental and environmental problems are a major focus of interest to scholars of personality. This is in part because the onset of personality disturbance occurs early in life and is frequently associated with real and perceived disruptive childhood experiences. Of particular interest has been the extremely high rate of reported neglect and childhood sexual, physical, or emotional abuse in patients with certain personality disorders, especially borderline personality disorder and histrionic personality disorder.
Genetic factors are often influential in the etiology of personality disorders. For example, family, twin, and adoption studies suggest that schizotypal personality disorder is linked to a family history of schizophrenia. Similar studies have delineated genetic factors related to antisocial and borderline disorders.
In the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), all mental disorders (e.g., bipolar disorder, schizophrenia, panic disorder) as well as the personality disorders are now diagnosed on one axis. Major mental disorders and personality disorders may coexist in one individual. Personality disorders in DSM-5 are described as "an enduring manifestation of inner experience and behavior that deviates markedly from the expectations of the individual's culture, is pervasive and inflexible becomes clearly evident in early adulthood and is stable over time, and leads to distress ...