[Mechanism of action of antidepressants]

Modifications in noradrenergic and serotonergic systems are involved in the central mechanism of action of antidepressants. Most antidepressants (electroconvulsive therapy included) induce a desensitization of the beta-noradrenergic receptor, as shown by a decrease in noradrenaline-stimulated cAMP production. Down-regulation of the beta receptor is often associated with desensitization, as well as modifications in the activity of the serotonergic system, among which alternations in 5-HT2 receptors are frequent. Finally, complex interactions between noradrenergic and serotonergic receptors may also contribute to the pharmacological effect of long term antidepressive treatment.