Dexamethasone suppression, protirelin stimulation, and insulin infusion in subtypes of recovered depressive patients.

Twenty-eight patients (10 bipolar, 13 depressive spectrum disease, and 5 familial pure depressive), recovered from depression for an average of 1 year, underwent a series of basal and provocative endocrine tests. No significant differences were found among depressive subtypes in thyrotropin, cortisol, or growth hormone measurements either before or after provocative testing with the exception of growth hormone response to insulin-induced hypoglycemia. Patients with depressive spectrum disease showed a significantly different growth hormone response to insulin-induced hypoglycemia than patients with bipolar disorder, a finding which suggests differences in alpha-adrenergic receptor sensitivity between these groups.