Repetitive transcranial magnetic stimulation (rTMS) may be an effective therapy for treatment-resistant bipolar depression, according to the results of a recent pilot study led by Guohua Xia, MD, PhD, assistant clinical professor of psychiatry at the University of California, Davis.1 Xia and colleagues undertook this study because rTMS has been shown to be effective in patients with major depressive disorder.2,3 However, there have been few studies of rTMS for bipolar depression, he said.

The study included patients 18 years and older with treatment-resistant bipolar depression, defined as a lack of response to more than 2 previous therapies and a Hamilton Depression Rating Scale (HAM-D) score over 18. Patients were treated using 20 Hz rTMS on the left dorsal prefrontal cortex for a total of 15 days (5 consecutive days for 3 weeks). Throughout this period, the patients also continued taking their previously prescribed medications, which remained at the same dose.

Of the 15 patients who participated in the study, the mean HAM-D score decreased from 29 at baseline to 11 after the treatment period. In 86% of patients, the HAM-D score decreased by at least 50%, and 57% of all patients reached remission. Three patients experienced tolerable focal pain, and this disappeared during the treatment period. No patients experienced seizure or manic symptoms.

Xia said many of his patients were surprised and pleased by the results. “Those who responded were amazed,” he said. “Many want to continue treatments.” Based on the effects of this study, Xia plans to lead a larger study to examine the effects of rTMS for treatment-resistant bipolar depression.