Personality disorders, formerly referred to as
character disorders, are a class of
personality types which deviate from the contemporary expectations of a society.
[1]A personality disorder is a severe disturbance in the characterological constitution and behavioral tendencies of the individual, usually involving several areas of the personality, and nearly always associated with considerable personal and social disruption. Personality disorder tends to appear in late childhood or adolescence and continues to be manifest into adulthood.
It is therefore unlikely that the diagnosis of personality disorder will be appropriate before the age of 16 or 17 years. General diagnostic guidelines applying to all personality disorders are presented below; supplementary descriptions are provided with each of the subtypes.
Diagnosis of personality disorders is very subjective; however, inflexible and pervasive behavioral patterns often cause serious personal and social difficulties, as well as a general functional impairment. Rigid and ongoing patterns of feeling, thinking and behavior are said to be caused by underlying belief systems and these systems are referred to as fixed fantasies or "dysfunctional schemata" (Cognitive modules).