Cortisol escape from morphine suppression

Abstract

Twenty-one unmedicated, sequentially admitted psychiatric patients of either sex and four male healthy volunteers were given an intravenous injection of 2.5 mg morphine. Blood samples were drawn immediately before and at 30-minute intervals for 3 hours after the injection and assayed for cortisol. Morphine suppressed cortisol secretion. Early resumption of cortisol secretion (escape) was more frequent in patients with a diagnosis of major depressive disorder and with abnormal dexamethasone suppression test results. The sensitivity of this infusion paradigm for the diagnosis of major depressive disorder was 40%, and the specificity was 82%. The implications of these findings for the pathophysiology of depression are discussed.