Repetitive Transcranial Magnetic Stimulation for Treatment of Medication-Resistant Depression in Older Adults

Abstract

The antidepressant effects of repetitive transcranial magnetic stimulation (rTMS) are well documented, but studies to date have produced heterogeneous results in late-life depression. To address this matter, we evaluated the efficacy of both high- and low-frequency rTMS delivered to the prefrontal cortex of older adults with treatment-resistant major depression. Forty-nine older adults (69 +/- 6.7 years) with treatment-refractory major depressive disorders underwent a series of rTMS treatments as an adjuvant to pharmacotherapy. Patients received high-frequency rTMS delivered to the left dorsolateral prefrontal cortex, low-frequency stimulation to the right dorsolateral prefrontal cortex, or a combination thereof, at 80-110% of the motor threshold. There was a modest, but statistically significant, mean reduction (24.7%) in Hamilton Depression Rating Scale (HDRS) scores from baseline to the end of treatment. Nine patients were classified as responders (50% HDRS reduction), and 4 patients reached remission status (final HDRS score <8). Similar improvements in HDRS scores were observed for high- and low-frequency rTMS. Treatment was generally well tolerated, and no serious adverse effects were reported. The findings support the contention that in older adults with treatment-refractory depression, rTMS can be an effective treatment alternative for some patients.