Transcranial Magnetic Stimulation for Anxiety Symptoms: An Updated Systematic Review and Meta-Analysis
- *Corresponding Author:
- Trevizol AP
Department of Psychiatry, Santa Casa Medical School
Rua Major Maragliano, 241, Vila Mariana, Brazil
E-mail: [email protected]
Received January 04, 2016; Accepted January 22, 2016; Published January 27,2016
Citation: Trevizol AP, Shiozawa P, Sato IA, Sachdev P, Sarkhel S, et al. (2016) Transcranial Magnetic Stimulation for Anxiety Symptoms: An Updated Systematic Review and Meta-Analysis. Abnorm Behav Psychol 2:108. doi: 10.4172/2472-0496.1000108
Copyright: © 2016 Trevizol AP, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Transcranial magnetic stimulation (TMS) is a promising non-invasive brain stimulation intervention. TMS has been proposed for the treatment of Anxiety Disorders and disorders in which anxiety symptoms are prevalent, such as Obsessive-Compulsive Disorder (OCD) and Post-traumatic Stress Disorder (PTSD).
Objective: To assess the efficacy of TMS for anxiety symptoms in Specific and Social Phobia, Generalized Anxiety Disorder, Panic Disorder (PD), OCD and PTSD in randomized clinical trials (RCTs).
Methods: Systematic review using MEDLINE from the first RCT available until January 2015. The main outcome was the Hedges’ g for continuous scores for anxiety symptoms scales in a random-effects model. Heterogeneity was evaluated with the I2 and the χ2 test. Publication bias was evaluated using the Begg’s funnel plot. Metaregression was performed using the random-effects model modified by Knapp and Hartung. Results: We included 14 RCTs (n=395); most had small-to-modest sample sizes. Comparing active vs. sham TMS, active stimulation was not significantly superior for anxiety symptoms (Hedges’ g = -0.02; 95% CI -0.24- 0.20). The funnel plot showed that the risk of publication bias was low and between-study heterogeneity was not significantly (I2=12%). Meta-regression showed no particular influence of any variable on the results.
Conclusion: TMS active was not superior to sham stimulation for the amelioration of anxiety symptoms. Trials had homogeneous results, despite different protocols of stimulation used. Further RCTs with larger sample sizes are fundamentally needed to clarify the precise impact of TMS in anxiety symptoms.
• We present a systematic review and meta-analysis on results of TMS for anxiety symptoms in anxiety disorders
• Four-teen studies (395 patients) were selected for the quantitative analysis
• We found that active TMS was not significantly superior to sham TMS in this dataset (Hedges’ g = -0.02; 95% CI -0.24-0.20)
• Heterogeneity was not significant in our analysis (I2=12% and p=0.361 for the χ2 test)
• Meta-regression showed no particular influence of any variable on the results
• The funnel plot displayed that studies were evenly distributed, with all studies within the limits deter-mined by the graphic except for one, indicating low bias.