Partial clinical response to 2 weeks of 2 Hz repetitive transcranial magnetic stimulation to the right parietal cortex in depression

The aim of this treatment study was to evaluate the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) over the right parietal cortex in depression. In a double-blind, sham-controlled design ten consecutive sessions of 2 Hz rTMS (inter-pulse interval 0.5 s) at 90% motor threshold to the right parietal cortex (2400 pulses per session) were applied to 34 patients with the primary diagnosis of DSM-IV depression and a score of > or =15 on the 17-item Hamilton Rating Scale for Depression (HAMD). The primary outcome measures were the percentage change from baseline on the 17-item HAMD scores after ten sessions, and the percentage of clinical (defined as > or =50% reduction in HAMD score) and partial clinical (defined as > or =30% reduction in HAMD score) responders. Reduction of HAMD scores in the real rTMS treatment (mean real+/-S.D., -19.9+/-32.5%) was not statistically different from the sham rTMS treatment (mean sham+/-S.D., -5.6+/-28.4%), and the number of clinical responders did not differ between treatments. However, a significant greater number of partial clinical responders were observed in the real (43.8%) compared to the sham rTMS treatment (6.3%). This study provides the first evidence showing that 2 Hz rTMS over the right parietal cortex may have antidepressant properties, and warrants further research.