Effectiveness of Repetitive Transcranial Magnetic Stimulation in the Treatment of Depression in the Elderly: A Retrospective Natural Analysis

Abstract

Introduction: Depression in the elderly is an understudied condition. Psychopharmacological and psychotherapeutic approaches suffer from specific difficulties with this patient group. Brain stimulation techniques such as repetitive transcranial magnetic stimulation (rTMS) offer a therapeutic alternative. rTMS remains understudied in this age group when compared with younger patients. Methods: A cohort of 505 patients with depression was analyzed in retrospect concerning their response to rTMS treatment. A total of 15.5% were 60 years old or older, defined as the elderly group of depressed patients. The majority of these were treated with high-frequency protocols over the left dorsolateral prefrontal cortex (DLPFC). For group comparisons, we used Student t-tests or chi-square-tests, depending on the scales of measurement. As measures for effect size, we used Cohen’s d for the relative and absolute change in the HDRS total score. Results: Groups did not differ significantly with respect to baseline depression severity or treatment parameters. In the group of elderly patients, a higher number of females were present. Groups did not differ significantly with respect to treatment efficacy, as indicated by the absolute and relative changes in the HDRS-21 sum score. Elderly patients tended to take higher numbers of mood stabilizers. Elderly patients showed a significantly superior reduction for the item “appetite” and a superior reduction tending towards significance for the item “work and interests”. Conclusions: Antidepressant rTMS treatment showed comparable efficacy for patients above 60 years to that in younger patients. Differences between the age groups concerning amelioration of distinct HDRS single items deserve further investigation.