High activity of acid sphingomyelinase in major depression

Acid sphingomyelinase (A-SMase) and its reaction product ceramide may play a role in the pathophysiology of depressive disorders and in the therapeutic action of antidepressive drugs. In a prospective case-control study, A-SMase activity was measured in peripheral blood mononuclear cells of 17 patients with a major depressive episode who were free of antidepressant drug therapy for at least 10 days and 8 healthy volunteers. In the patient group, A-SMase activity was correlated to the score (n = 17, r = 0.64, P = 0.005). The patient group exhibited higher A-SMase activity compared to healthy volunteers (T = 2.09, df = 21.33, P < 0.05). In addition, we demonstrate that the antidepressants imipramine and amitriptyline induce a long-term reduction of the activity of A-SMase in cultured cells.