The relationship of borderline personality disorder to the affective disorders.

The proposition that Borderline Personality Disorders (BPDs) are atypical forms of affective disorder is reviewed in the light of pharmacological, outcome and clinical studies. The case can be summarized briefly as follows: that the basic underlying cause of borderline symptomatology is an effective disorder; that mood disturbance, which is viewed as primarily biological, is more important than developmental experience and life events in maintaining borderline personality features; that therapies aimed at treating the mood disorder should therefore be expected to relieve the personality disorder. However, the pharmacological studies suggest that antidepressant medications have been largely ineffective in treating well defined BPD, except in the presence of coexisting depressive disorder. Indeed low dose antipsychotics have a demonstrated efficacy in the treatment of BPD, which does not strengthen the case for an affective etiology. Follow-up studies of BPDs suggest that dramatic characterological features seen at the time of index hospitalization tend to recede by the time patients are in their 30s, that major affective disorders fail to emerge over time, and that long-term marginal functioning derives from long-term maladaptive patterns across a variety of areas. Clinical studies suggest that 20-60 per cent of patients with BPD have a concomitant depressive disorder. Conversely the prevalence of personality disorders in depressions varies with depressive category, with considerably higher incidence of personality disturbance found in non-endogenous depression. The high rate of coexistence of these two disorders does not imply causality or primacy, in the sense that it is the affective disorder which brings out and causes the personality disorder. The review concludes that the assertion that BPD represents atypical affective disorder begs the possibility that it is precisely in having borderline features that they are atypical, and hence distinct.