Repetitive transcranial magnetic stimulation in patients with drug-resistant major depression: A six-month clinical follow-up study

Objective. In this study we aimed to assess the long-term efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) on depressive symptoms and cognitive performance in patients with drug-resistant major depressive disorder (MDD). Methods. Fifteen drug-resistant depressed outpatients completed an acute trial with augmentative high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC) and were compared with 15 drug-resistant MDD patients who underwent sham procedure. Depressive symptoms were evaluated with the Hamilton Depression Rating Scale and Montgomery-Asberg Depression Rating Scale. The Frontal Assessment Battery and the Stroop Color-Word Test Interference (Stroop T) were used to probe executive functions. Outcome measures were obtained at baseline, 4 weeks after the rTMS, as well as 3 months and 6 months after the end of the stimulation protocol. Results. After the active rTMS, patients showed a significant decrease in the scores at the depression rating scales that lasted for 6 months. A transient improvement was also observed at the Stroop T, although it did not persist in time. Conclusions. High-frequency rTMS over the left DLPFC may have long-term antidepressant effect in drug-resistant MDD. TMS is a valuable tool for the add-on treatment of mood disorders and for the design of customized stimulation protocols.