High-Frequency External Muscle Stimulation Reduces Depressive Symptoms in Older Male Veterans: A Pilot Study

Late-life depression (LLD) is a severe public health problem. Given that pharmacological treatments for LLD are limited by their side effects, development of efficient and tolerable nonpharmacological treatment for LLD is urgently required. This study investigated whether high-frequency external muscle stimulation could reduce depressive symptoms in LLD.

Twenty-two older male veterans with major depression were recruited and randomized into a treatment (n = 9) or sham control group (n = 13). The groups received high-frequency external muscle stimulation or sham intervention 3 times per week for 12 weeks. Clinical symptoms and muscle strength were evaluated at baseline and every 2 weeks.

The 2 groups were homogeneous in age, baseline clinical symptoms, and muscle strength. The treatment group showed significant improvement in depression and anxiety scores and muscle strength (all P < .01), whereas the control group showed no significant change after the 12-week follow-up. Compared to the control group, the treatment group showed significant improvements in depression (Geriatric Depression Scale, P = .009; Hamilton Depression Rating Scale, P = .007) and anxiety scores (HAMA, P = .008) and muscle strength (all P < .001). Changes in depression and anxiety levels were significantly correlated with changes in muscle strength after the study. In the treatment group, we observed a trend of correlation between the reduction in depression and muscle strength gains.

High-frequency external muscle stimulation appears to be an effective treatment for older patients with LLD. Large studies with more tests and/or conducted in different populations are warranted to validate these preliminary findings.