DOPAMINE AND DEPRESSION - STRIATAL DOPAMINE D-2 RECEPTOR SPECT BEFOREAND AFTER ANTIDEPRESSANT THERAPY

Ten unmedicated and ten medicated patients with major depression and t en controls were investigated with IBZM-SPECT. The ten unmedicated pat ients were reinvestigated after treatment with tricyclic antidepressan ts. Dopamine D-2 receptor occupancy was not different between patients and controls, or medicated and unmedicated patients. IBZM binding was increased in four patients with psychomotor retardation, Antidepressa nt therapy led to a decrease in IBZM binding in the five improved pati ents. Dopamine D-2 receptor binding remained unchanged in nonresponder s. It is concluded that striatal dopamine D-2 receptor binding is not changed in depression or by tricyclic antidepressants; however, it is affected by psychomotor activity. The changes observed might be the re sult of increased tonic dopamine release in the basal ganglia, but sev eral other explanations exist.