Platelet serotonergic markers of the clinical efficacy of electroconvulsive therapy of endogenous depression

The changes of main platelet serotonergic parameters (maximal velocity of H-3-serotonin uptake, V-max; and density of (3)3H-imipramine binding sites, B-max) were followed up in 25 endogenously depressed patients before and after electroconvulsive therapy (ECT). It was found a marked decrease in the velocity of H-3-serotonin uptake into platelets (V-max) from patients before ECT (especially in non-responder group) and the significant increase of V-max- and B-max-values after the course of ECT in responders but not in resistant patients (non-responders). The increase of V-max- and B-max-values in responders was evidence of the rise of the functional activity serotonin system after treatment. The results evidence about the significance of serotonergic mechanisms in the therapeutic efficacy of ECT.