THE PHARMACODYNAMIC EFFECTS OF ANTIDEPRESSANT DRUGS - A SHORT REVIEW

Resent research on the mechanisms of action of antidepressant treatment (ADT) has led to major revision of earlier concepts. The monoamine deficiency hypothesis seems to be too simplistic, as it does not account for the great temporal discrepancy between the rapid drug-induced biochemical effects of amine uptake and catabolism, which occurs within hours, and the antidepressant response, which occurs after at least 7-14 days. The pharmacodynamic effects of ADT are obviously complex involving a great number of interacting transmitter and receptor systems in the central nervous system. Secondary adaptive changes in neuronal systems seem to play an integral and possibly pivotal role in antidepressant drug action. Our knowledge about the details is sparse, primarily because most investigations on the subject are based on animal studies or in vitro technics, whereas the number of clinical investigations of the antidepressant drug effect on the living human organism is limited. This fact may explain the often-found discrepancy between experimental and clinical effect.