Low- vs High-Frequency Repetitive Transcranial Magnetic Stimulation as an Add-On Treatment for Refractory Depression

Objectives: Repetitive transcranial magnetic stimulation (rTMS) seems to be effective as an antidepressant, however, some confusion remains about the best parameters to apply and the efficacy of its association with pharmacological antidepressant treatments. Method: In a single blind randomized study 14 patients with unipolar resistant depression to one antidepressant treatment were enrolled to receive, in combination with venlafaxine (150 mg), either 20 sessions of 10 Hz rTMS (2000 pulses per session) applied over the left dorsolateral prefrontal cortex (DLPFC) or 20 sessions of 1 Hz rTMS (120 stimulations per sessions) applied over the right DLPFC. Results: A similar antidepressant effect was observed in both groups with a comparable antidepressant delay of action (2 weeks) and a comparable number of responders (MADRS < 15) after 4 weeks of daily rTMS sessions (66 vs 50%). Conclusion: Low- and high- frequency rTMS seems to be effective as an add-on treatment to venlafaxine as monotherapy in pharmacological refractory major depression (stage 1). Due to its short duration (one session of 1 Hz rTMS lasts 4 min vs 16 for 10 Hz rTMS) and its safety, low frequency rTMS may be a useful alternative treatment for patients with refractory depression.