Affective disorders: II. Recent advances in laboratory and pathogenetic approaches.

Part II of a two-part review of affective disorders covers laboratory and pathogenetic approaches. Recent developments in psychoendocrinology and sleep electroencephalography have provided the clinician with biologic procedures that may serve as ancillary laboratory tests to support the clinical diagnosis of affective illness. These laboratory markers have provided indirect evidence for disturbed limbic-diencephalic functioning in these disorders. Such disturbances in turn seem to reflect the convergence of multiple etiologic variables. Further, recent advances in pathogenetic mechanisms suggest that the clinical heterogeneity of affective syndromes derives from the interaction of predisposing genetic, developmental, and personality variables with proximate social and physiochemical stressors.