An Updated Meta-Analysis: Short-Term Therapeutic Effects of Repeated Transcranial Magnetic Stimulation in Treating Obsessive-Compulsive Disorder

TITLE
An Updated Meta-Analysis: Short-Term Therapeutic Effects of Repeated Transcranial Magnetic Stimulation in Treating Obsessive-Compulsive Disorder

AUTHORS
Zhou DD; Wang W; Wang GM; Li DQ; Kuang L. Institution Zhou, Dong-Dong. Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, China. Wang, Wo. Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, China. Wang, Gao-Mao. Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, China. Li, Da-Qi. Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, China. Kuang, Li. Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, China; Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.

ELECTRONIC ADDRESS
kuangli0308@163.com

SOURCE
Journal of Affective Disorders. 215:187-196, 2017 Jun.

BACKGROUND
This study was conducted to evaluate the short-term therapeutic effects of using repeated transcranial magnetic stimulation (rTMS) to treat obsessive-compulsive disorder (OCD) and to examine potential influencing factors.

METHOD
We searched the PubMed, EMBASE, CENTRAL, Wanfang, CNKI, and Sinomed databases on September 18, 2016 and reviewed the references of previous meta-analyses. Sham-controlled, randomized clinical trials using rTMS to treat OCD were included. Hedge’s g was calculated for the effect size. Subgroup analyses and univariate meta-regressions were conducted.

RESULTS
Twenty studies with 791 patients were included. A large effect size (g=0.71; 95%CI, 0.55-0.87; P<0.001) was found for the therapeutic effect. Targeting the supplementary motor area (SMA) (g=0.56; 95%CI, 0.12-1.01; P<0.001), left dorsolateral prefrontal cortex (DLPFC) (g=0.47; 95%CI, 0.02-0.93; P=0.02), bilateral DLPFC (g=0.65; 95%CI, 0.38-0.92; P<0.001) and right DLPFC (g=0.93; 95%CI, 0.70-1.15; P<0.001), excluding the orbitofrontal cortex (OFC) (g=0.56; 95%CI, -0.05-1.18; P=0.07), showed significant improvements over sham treatments. Both low-frequency (g=0.73; 95%CI, 0.50-0.96; P<0.001) and high-frequency (g=0.70; 95%CI, 0.51-0.89; P<0.001) treatments were significantly better than sham treatments, with no significant differences between the effects of the two frequencies. The subgroup analyses indicated that patients who were non-treatment resistant, lacked concurrent major depressive disorder (MDD) and received threshold-intensity rTMS showed larger therapeutic effects than the corresponding subgroups. The subgroup analysis according to sham strategy showed that tilted coils yielded larger effects than sham coils. Meta-regression analyses revealed that none of the continuous variables were significantly associated with the therapeutic effects.

LIMITATIONS
Only short-term therapeutic effects were assessed in this study.

CONCLUSIONS
Based on this study, the short-term therapeutic effects of rTMS are superior to those of sham treatments. The site of stimulation, stimulation frequency and intensity and sham condition were identified as potential factors modulating short-term therapeutic effects. The findings of this study may inspire future research.