The biology of affective disorders.

The clinical features, genetic data, psychopharmacological studies, hormonal abnormalities, and biochemical observations all serve to define major depressive illness as an inherited neurochemical disorder affecting the hypothalamus, and probably involving monoamine pathways. While the precise nature of the defect and its mode of transmission remain obscure, the rapid development of this field in less than two decades permits optimism that major depressive illness illness will be among the first "functional" psychiatric disorders to have its chemical pathology elucidated.