The impact of high-frequency repetitive transcranial magnetic stimulation on fine motor functions in medication-resistant major depression

OBJECTIVES: Although high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) over the left dorsolateral prefrontal cortex (DLPFC) has been reported to improve mood symptoms in major depressive disorder (MDD), research on its impact on psychomotor symptoms is scarce. This study assessed the psychomotor effects of 1 and 10 sessions, respectively, of HF-rTMS over the left DLPFC.

METHODS: Ten HF-rTMS sessions were applied in 21 medication-free MDD patients over a 2-week period. At the beginning, one placebo (sham)-controlled rTMS session was also applied in a cross-over, single-blind design. Psychomotor variables were digitally recorded during completion of a Fitts' task, at baseline, after the first and second real/sham session and at the end point.

RESULTS: The total 10-session treatment period resulted in a decrease of depression severity. One HF-rTMS session resulted in improvements on the Fitts' task, without a difference between active and sham stimulation, however. No further improvements occurred from session 2 to session 10.

CONCLUSIONS: No evidence was provided to link the observed psychomotor improvements to HF-rTMS stimulation, as a practice effect could have impacted the significant psychomotor outcomes.