Psychotropic and antinociceptive effects of antidepressants: Hypotheses regarding mode of action

Abstract

Antidepressant drugs are effective not only in the treatment of depression but also in the treatment of a large number of psychiatric disorders which may, or may not, be pathophysiologically related to affective illness (such as panic disorder, generalized anxiety, obsessive compulsive disorder, social phobia, bulimia, and premenstrual syndrome). Also patients with chronic pain often respond favourally to treatment with these compounds; partly this may be due to the psychotropic effects of the drugs, but partly also to a genuine analgesic effect. In this review the possible mode of action of antidepressants with respect psychotropic as well as antinociceptive effects is discussed. Focused are the effects of antidepressant drugs, at acute and chronic administration, respectively, on the serotonin synapse in brain, but also the possible involvement of noradrenaline and endogenous opioids in the pharmacodynamics of these compounds is briefly discussed.