Evidence-based umbrella review of non-invasive brain stimulation in anxiety disorders

Background and objectives

Although several meta-analyses have suggested the efficacy of non-invasive brain stimulation (NIBS) mainly in prefrontal brain areas to treat mental disorders, no synthetic approach has been performed for other psychiatric disorders rather than depression. The objective is to assess the available evidence of NIBS in the treatment of anxiety disorders.

Methods

An umbrella review (CRD42021239577) was performed only looking for reviews with meta-analyses of randomized clinical trials using a source strategy MeSH keywords in MEDLINE through Pubmed by two independent researchers. The effects of different methods of NIBS in anxiety disorders were assessed using the PICO strategy. The methodological quality was evaluated using AMSTAR-2 and certainty of evidence using the GRADE-pro framework.

Results

From 136 screening meta-analyses, 16 from 14 studies were included in the final analysis. Generalized Anxiety Disorder (GAD) and Obsessive Compulsive Disorder (OCD) respond best to low frequency repetitive transcranial magnetic stimulation (rTMS), while Posttraumatic Stress Disorder (PTSD) has the largest effect size at high frequency rTMS. Panic Disorder (PD) has no evidence for clinical use of NIBS. There were not identified meta-analyses about other anxiety disorders. In general, the included studies had good methodological quality, but low to moderate evidence for clinical recommendation.

Conclusion

Available evidence reveals NIBS as an effective and safe approach to treat GAD, PTSD and OCD with low recommendation level to clinical application. A great heterogeneity of studies indicates the necessity to develop new randomized clinical trials applying NIBS to treat those and other mental disorders.