The regulation of limbic system - hypothalamus-pituitary-adrenal cortical function is being studied in patients with psychiatric disorders. Some patients with endogenomorphic depression (unipolar and biopolar) show abnormal escape from neuroendocrine suppression by dexamethasone. Most other psychiatric patients have normal suppression responses. A subgroup of the endogenomorphic depressives can be identified by this strategy at confidence levels of 90%-100%. The overall objective is to use this laboratory test procedure as part of the clinical diagnostic workup for depression. We are now studying graded doses of dexamethasone to establish the optimal dose for specificity and sensitivity. The clinical features and endocrine responses will then be studied by multivariate analysis to attempt to derive an improved classification of depressed patients. Secondary objectives of the project are to compare the clinical utility of urinary 17-OHCS and urinary free cortisol excretion as psychoendocrine measures, and to study plasma and urinary corticosterone levels in depressed, dysphoric patients. BIBLIOGRAPHIC REFERENCES: Carroll, B.J. (1977): Mood disturbances and pituitary-adrenal diseases. Psychosomatic Medicine, 39: 54. Carrol, B.J., Feinberg, M., Steiner, M.S., Commorato, A., James, N. (1977); Neuroendocrine identification of endogenomorphic depression. Psychosomatic Medicine, 39: 54-55.