Lithium Induces Rapid Relief of Depression in Tricyclic Antidepressant Drug Non-Responders

Eight patients suffering from a major unipolar depression and having field to respond to treatment for three weeks or more with tricyclic antidepressants were given lithium. All eight patients experienced a remarkable relief of their depression within 48 hours. This rapid antidepressant effect of lithium in "treatment-resistant' patients might be due to the enhancement of the efficacy of the central serotoninergic system, unveiling the tricyclic antidepressant-induced sensitization of the serotoninergic postsynaptic receptors.