An essential feature of this disorder is a pervasive pattern of instability of self-image, interpersonal relationships, and mood, beginning in early adulthood and present in a variety of contexts.
A marked and persistent identity disturbance is almost invariably present. This is often pervasive, and is manifested by uncertainty about several life issues, such as self-image, sexual orientation, long-term goals or career choice, types of friends or lovers to have, and which values to adopt. The person often experiences this instability of self-image as chronic feelings of emptiness and boredom.
Interpersonal relationships are usually unstable and intense, and may be characterized by alternation of the extremes of overidealization and devaluation. These people have difficulty tolerating being alone, and will make frantic efforts to avoid real or imagined abandonment.
Affective instability is common. This may be evidenced by marked mood shifts from baseline mood to depression, irritability, or anxiety, usually lasting a few hours or, only rarely, more than a few days. In addition, these people often have inappropriately intense anger with frequent displays of temper or recurrent physical fights. They tend to be impulsive, particularly in activities that are potentially self-damaging, such as shopping sprees, psychoactive substance abuse, reckless driving, casual sex, shoplifting, and binge eating.
Recurrent suicidal threats, gestures, or behavior and other self-mutilating behavior (e.g., wrist-scratching) are common in the more severe forms of the disorder. This behavior may serve to manipulate others, may be a result of intense anger, or may counteract feelings of “numbness” and depersonalization that arise during periods of extreme stress.…
Associated Features. Frequently this disorder is accompanied by many features of other Personality Disorders, such as Schizotypal, Histrionic, Narcissistic, and Antisocial Personality Disorders. In many cases more than one diagnosis is warranted. Quite often social contrariness and a generally pessimistic outlook are observed. Alternation between dependency and self-assertion is common. During periods of extreme stress, transient psychotic symptoms may occur, but they are generally of insufficient severity or duration to warrant an additional diagnosis.
Impairment. Often there is considerable interference with social or occupational functioning.
Complications. Possible complications include Dysthymia [depressive neurosis], Major Depression, Psychoactive Substance Abuse, and psychotic disorders such as Brief Reactive Psychosis. Premature death may result from suicide.
Sex Ratio. The disorder is more commonly diagnosed in women.
Prevalence. Borderline Personality Disorder is apparently common.
Predisposing and Familial Pattern. No information.
Differential Diagnosis. In Identity Disorder there is a similar clinical picture, but Borderline Personality Disorder preempts the diagnosis of Identity Disorder if the criteria for Borderline Personality Disorder are met, the disturbance is sufficiently pervasive and persistent, and it is unlikely that it will be limited to a developmental stage.…
* From the Diagnostic and Statistical Manual of Mental Disorders, 3d edition, revised (1987), pp. 346–47