Different frequency repetitive transcranial magnetic stimulation (rTMS) for posttraumatic stress disorder (PTSD): A systematic review and meta-analysis

Posttraumatic stress disorder (PTSD) is a psychiatric disorder. Repetitive transcranial magnetic stimulation (rTMS) has been found to be effective for treating PTSD, but whether different frequencies have different effects remains controversial. We conducted this systematic review and meta-analysis to address this question. We searched the literature for studies written in English or Chinese in 9 electronic databases from the databases' inception to August 1, 2016. Additional articles were identified from the reference lists of identified studies and from personal reference collections. Eighteen articles were included, and 11 were suitable for the meta-analysis (Combined sample size was 377 (217 in active rTMS groups, 160 in sham-controlled groups)). Low-frequency (LF) rTMS resulted in a significant reduction in the PTSD total score and the depression score (1. PTSD total score: pooled SMD, 0.92; Cl, 0.11-1.72; 2. Depression: pooled SMD, 0.54; CI, 0.08-1.00). High-frequency (HF) rTMS showed the following results: 1. PTSD total score: pooled SMD, 3.24; CI, 2.24-4.25; 2. re-experiencing: pooled SMD, -1.77; CI, -2.49(-1.04); 3. Avoidance: pooled SMD, -1.57; CI, -2.50-(-0.84); 4. hyperarousal: pooled SMD, -1.32; CI, -2.17-(-0.47); 5. depression: pooled SMD, 1.92; CI, 0.80-3.03; and 6. Anxiety: pooled SMD, 2.67; CI, 1.82-3.52. Therefore, both HF and LF rTMS can alleviate PTSD symptoms. Although the evidence is extremely limited, LF rTMS can reduce overall PTSD and depression symptoms. HF rTMS can improve the main and related symptoms of PTSD. However, additional research is needed to substantiate these findings. (C) 2017 Elsevier Ltd. All rights reserved.