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.
From the *Department of Psychiatry, Queen's University, Kingston; †Department of Psychiatry, University of Toronto, Toronto; ‡Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton; and §Queen's University, Kingston, ON, Canada.
Received for publication January 4, 2008; accepted March 20, 2008.
Reprints: Roumen Milev, MD, PhD, FRCPsych(UK), FRCP(C), Department of Psychiatry, Queen's University, c/o Providence Care, MHS, 752 King Street West, Kingston, ON, Canada K7L 4X3 (e-mail: firstname.lastname@example.org).