Induction of a mixed depressive episode during rTMS treatment in a patient with refractory major depression

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive experimental technique which has mostly been investigated in the treatment of mood disorders with possible efficacy in depression. Among its potential side effects, there have been some reports of rTMS-induced (hypo)mania in the literature but none for rTMS-induced mixed episodes. We report the case of a 39-year-old woman suffering from refractory chronic major depression who developed a depressive mixed episode associated with a mild serotonin syndrome during her second week of rTMS treatment. She was receiving a combination of antidepressants, the doses of which were kept unchanged during rTMS treatment. Mixed as well as manic episodes may be induced by transcranial magnetic stimulation, complications already observed with antidepressants and electroconvulsive therapy. Therefore, caution should be exercised among clinicians using this experimental procedure, particularly in the treatment of bipolar depressed patients.