Brain Stimulation in Obsessive-Compulsive Disorder (OCD): A Systematic Review

Abstract

Background: Obsessive-compulsive disorder (OCD) is a highly prevalent, severe, and chronic disease. There is a need for alternative strategies for treatment-resistant OCD. Objective: This review aims to assess the effect of brain stimulation techniques in OCD. Methods: We included papers published in peer-reviewed journals dealing with brain stimulation techniques in OCD. We conducted treatment-specific searches for OCD (Technique AND ((randomized OR randomised) AND control* AND trial) AND (magnetic AND stimulation OR (rTMS OR dTMS)) AND (obsess* OR compuls* OR OCD)) on six databases, i.e., PubMed, Cochrane, Scopus, CINAHL, PsycINFO, and Web of Science to identify randomised controlled trials and ClinicalTrials.gov for possible additional results. Results: Different add-on stimulation techniques could be effective for severely ill OCD patients unresponsive to drugs and/or behavioural therapy. Most evidence regarded deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), while there is less evidence regarding transcranial direct current stimulation (tDCS), electroconvulsive therapy, and vagus nerve stimulation (for these last two there are no sham-controlled studies). Low-frequency TMS may be more effective over the supplementary motor area or the orbitofrontal cortex. DBS showed best results when targeting the crossroad between the nucleus accumbens and the ventral capsule or the subthalamic nucleus. Cathodal tDCS may be better than anodal in treating OCD. Limitations. We had to include methodologically inconsistent underpowered studies. Conclusion: Different brain stimulation techniques are promising as an add-on treatment of refractory OCD, although studies frequently reported inconsistent results. TMS, DBS, and tDCS could possibly find some use with adequate testing, but their standard methodology still needs to be established.

Schizo-obsessive disorder and neurosurgery for schizophrenia

“…Functional neuroimaging by Bleich-Cohen and colleagues demonstrated obsessive hallucinations in schizo-obsessive disorder actually involved the dorsolateral prefrontal cortex, orbitofrontal cortex, inferior frontal gyrus, middle frontal gyrus and middle temporal gyrus, regions shared between hallucinations and obsessions 13. Critical structures involved in OCD are the anterior limb of the internal capsule, ventral capsule, ventral striatum, nucleus accumbens and ventral caudate, anterior cingulate, and are targeted in neurosurgeries 15. Critical surgical structures in schizophrenia are anterior corpus callosum, frontal white matter, subcaudate region, hippocampus and anterior cingulate 3 16.…”

“…Notably, DBS for treatment of OCD is highly successful 15. OCD patients treated by DBS typically report that not only compulsions but the obsessions underlying them resolve 19.…”

Clinical advances in obsessive-compulsive disorder: a position statement by the International College of Obsessive-Compulsive Spectrum Disorders

“…Furthermore, studies present significant heterogeneity and methodological differences in sample selection criteria, concomitant treatment and tDCS stimulation protocols (da Silva et al, 2019;Rachid, 2019). Some authors suggest that overall cathodal tDCS may be better than anodal in treating OCD (Rapinesi et al, 2019).…”

Are current pharmacotherapeutic strategies effective in treating OCD?

“…The efficacy of multimodal antidepressants with serotonin-reuptake properties such as vortioxetine and vilazodone has to be evaluated. There is also emerging evidence for various brain stimulation techniques as augmenters [34]. There is a need to evaluate their dynamic interaction with ongoing pharmacological and psychotherapeutic treatments.…”