Pharmacological mechanisms of T3 augmentation of antidepressant action

Pharmacological mechanisms which have been proposed to account for the potentiating effect of T3 on antidepressant action include actions via nuclear receptors on gene expression, effects on membrane-bound receptors, and actions at the second-messenger level. Interactions of T3 with mechanisms involved in noradrenergic and serotonergic neurotransmission are of particular interest in that these systems have been implicated in the neurobiology of depression and in the actions of antidepressant drugs. Several examples of such interactions are discussed.