[Mechanisms of action of the antidepressants (author's transl)].

The tricyclic and related antidepressants reduce monoamine uptake at the synapses, block the presynaptic receptors and, after chronic administration, act upon the synthesis of the monoamines and the sensitivity of the post-synaptic receptors. The NA and 5-HT synapses are influenced to different degrees by the antidepressants: for example, desipramine has a preponderance of activity at NA synapses and clomipramine at 5-HT synapses. By combining these findings and by highlighting one or other of these properties, it is possible to come to diametrically opposite conclusions upon the effect of the antidepressants upon monoamine performance (activation or inhibition) and to develop many models of the mechanisms of antidepressant action. The authors describe some of these and stress the model which is at the basis of the studies being carried out at the Department of Psychiatry of the University of Geneva.