criteria are also provided for each of the pe rsonality disorders included in this chapter. 
The diagnosis of personality disorders requires an evaluation of the individual’s long-
term patterns of functioning, and the partic ular personality features must be evident by
early adulthood. The personality traits that define these disorders must also be distin-
guished from characteristics th at emerge in response to sp ecific situational stressors or
more transient mental states (e .g., bipolar, depressive, or an xiety disorders; substance in-
toxication). The clinician should assess the stability of pers onality traits over time and
across different situations. Although a single interview with the in dividual is sometimes
sufficient for making the diagnosis, it is of ten necessary to conduct more than one inter-
view and to space these over time. Assessment ca n also be complicated by the fact that the
characteristics that define a personality di sorder may not be considered problematic by
the individual (i.e., the traits are often ego-sy ntonic). To help overcome this difficulty, sup-
plementary information from other informants may be helpful.
Development and Course
The features of a personality disorder usually become recogn izable during adolescence or
early adult life. By definition, a personality disorder is an enduring pattern of thinking,
feeling, and behaving that is relatively stable  over time. Some types of personality disorder
(notably, antisocial and borderli ne personality disorders) tend to become less evident or to
remit with age, whereas this appears to be less true for some other types (e.g., obsessive-
compulsive and schizotypal personality disorders).
Personality disorder categories may be app lied with children or adolescents in those
relatively unusual instances in which the individual’s particular maladaptive personality
traits appear to be pervasive, persistent, an d unlikely to be limited to a particular devel-