Current evidence suggests that high frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) of the left dorsolateral prefrontal cortex (DLPFC) might be a promising treatment strategy for depression. However, due to rather modest clinical results, the efficacy of rTMS in depressed patients is still under debate. As melancholic depression seems to affect psychomotor activity, in this study, we wanted to evaluate whether HF-rTMS treatment affects psychomotor activity. We also wanted to examine whether the severity of psychomotor retardation could predict clinical outcome.

Our group consisted of twenty antidepressant-free unipolar depressed patients of the melancholic subtype. All were considered at least stage II treatment resistant. Depression severity was assessed with the Hamilton Depression Rating Scale (HDRS) and psychomotor symptoms with the Depressive Retardation Rating Scale (DRRS). All received 10 sessions of HF-rTMS delivered on the left DLPFC.

Forty percent of the patients showed a reduction of at least 50% on their initial HDRS score and were defined as HF-rTMS responders.

The severity of psychomotor retardation, as measured with the DDRS, did not predict clinical outcome. HF-rTMS treatment resulted in significant decreases in DDRS scores for responders as well as for non-responders. However: the better the clinical outcome, the higher the observed level of psychomotor improvement.

Our results suggest that HF-rTMS might act on the ‘psychomotor’ level and this might add some further information as to why this kind of treatment can be beneficial for severely depressed patients of the melancholic subtype.