Studies on the neurochemical basis of action of antidepressant drugs and electroconvulsive treatment.

Biochemical and behavioral studies on the mode of action of various antidepressant treatments supplied evidence that the effect of these treatments on cerebral neurotransmitter systems is more complex than it is assumed by the widely recognized "adrenoceptor down-regulation" hypothesis. As far as the central adrenergic system is concerned, it seems that antidepressant therapies in addition to down-regulation" of the beta-adrenergic system upregulate the alpha-adrenoceptor system. The facilitation of neurotransmission in alpha-adrenergic structures is affected by concomitant upregulation of alpha-1 adrenoceptors and downregulation of pre- and post-synaptic alpha-2 adrenoceptors. The action of antidepressant treatments is not limited to changes in adrenergic transmission, and the action of ECT on serotonergic and histaminergic system was also significant.