INCREASED PLATELET 5-HT2 RECEPTOR-BINDING AFTER ELECTROCONVULSIVE-THERAPY IN DEPRESSION

We investigated the effect of electroconvulsive treatment (ECT) on pla telet C-14-serotonin uptake, H-3-paroxetine binding and 5-HT2 receptor s in 12 patients (10 women and 2 men) unresponsive to pharmacological treatment. The mean numbers of ECTs given was 6.1 +/- 1.5. Mean treatm ent days was 14.6 +/- 3.8. Mean percent reduction in MADRS scores was 80.7 +/- 19.7 (p <0.002). The number of 5-HT2 receptors increased sign ificantly and uniformly after ECT (p = 0.011). There was no correlatio n between the degree of increase in 5-HT2 receptor densities and the r eduction in MADRS scores after ECT. There was no difference in mean B- max for platelet H-3-paroxetine binding before and after ECT. Bmax inc reased in six patients and decreased in six patients. The study shows an increase in platelet 5-HT2-receptor densities in depression after r epeated ECT. Recognizing the similarities between 5-HT2 receptors in p latelets and cerebral cortex, it seems reasonable to assume that a sim ilar upregulation of cortical 5-HT2 receptors occurs after ECT.