Transcranial Direct Current Stimulation for Obsessive-Compulsive Disorder: A Systematic Review

Abstract

Despite the advances in psychopharmacology and established psychotherapeutic interventions, more than 40% of patients with obsessive-compulsive disorder (OCD) do not respond to conventional treatment approaches. Transcranial direct current stimulation (tDCS) has been recently proposed as a therapeutic tool to alleviate treatment-resistant symptoms in patients with OCD. The aim of this review was to provide a comprehensive overview of the current state of the art and future clinical applications of tDCS in patients with OCD. A literature search conducted on the PubMed database following PRISMA guidelines and completed by a manual search yielded 12 results: eight case reports, three open-label studies (with 5, 8, and 42 participants), and one randomized trial with two active conditions (12 patients). There was no sham-controlled study. A total of 77 patients received active tDCS with a large diversity of electrode montages mainly targeting the dorsolateral prefrontal cortex, the orbitofrontal cortex or the (pre-) supplementary motor area. Despite methodological limitations and the heterogeneity of stimulation parameters, tDCS appears to be a promising tool to decrease obsessive-compulsive symptoms as well as comorbid depression and anxiety in patients with treatment-resistant OCD. Further sham-controlled studies are needed to confirm these preliminary results.

Keywords: OCD; brain stimulation; compulsion; neuromodulation; obsession; tDCS.

Figure 1

PRISMA flow diagram of selected studies in the qualitative analysis.

Figure 2

Illustration of the diversity in electrodes montage observed in transcranial direct current stimulation (tDCS) studies aiming to alleviate obsessive-compulsive symptoms in patients with treatment-resistant obsessive-compulsive disorder. A: Anode; C: Cathode. Hazari et al., 2016 [17]; Dinn et al., 2016 [18]; Alizadeh Goradel et al., 2016 [19]; Volpato et al., 2013 [20]; Narayanaswamy et al., 2015 [21]; Mondino et al., 2015 [22]; D’Urso et al., 2016a [23]; Silva et al., 2016 [24]; Palm et al., 2017 [25]; Bation et al., 2015 [26]; Najafi et al., 2017 [27]; D’Urso et al., 2016b [28].