Repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression in Parkinson disease: a meta-analysis of randomized controlled clinical trials

The objective of this meta-analysis was to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression in patients with Parkinson disease in order to arrive at qualitative and quantitative conclusions about the efficacy of rTMS. We included randomized controlled trials examining the effects of rTMS compared with sham-rTMS or selective serotonin re-uptake inhibitors (SSRIs). The quality of included studies was strictly evaluated. Data analyses were performed using the RevMan5.1 software. Eight studies including 312 patients met all inclusion criteria. The results showed that rTMS could evidently improve the HRSD score compared with sham-rTMS (p < 0.00001). However, we found similar antidepressant efficacy between rTMS and SSRIs groups in terms of HRSD and BDI score (p = 0.65; p = 0.75, respectively). Furthermore, patients who received rTMS could evidently show improvement on the unified Parkinson's disease rating scale (UPDRS), ADL score, and UPDRS motor score compared with sham-rTMS or SSRIs (p < 0.05, p = 0.05, respectively). The subgroup analysis by frequency of rTMS evidenced that the efficacy of low-frequency rTMS was superior to sham-rTMS (p < 0.0001) in terms of the outcome measure according to HAMD scale. Meanwhile, the high-frequency rTMS has the same antidepressant efficacy as SSRIs (p = 0.94). The current meta-analysis provided evidence that rTMS was superior to sham-rTMS and had similar antidepressant efficacy as SSRIs, and may have the additional advantage of some improvement in motor function.