Descriptive, biological, and theoretical aspects of borderline personality disorder.

Although the diagnosis of borderline personality disorder has reasonable interrater and test-retest reliability, its discriminative validity is poor. The authors review studies indicating that the patient group subsumed by the borderline category actually includes those with various affective, organic, and schizotypal disorders. They speculate that borderline personality disorder represents a broad range of affective disorders resulting in part from childhood object loss, which may impair the reinforcement mechanisms necessary for the development of competent object relations.