Could Transcranial Direct Current Stimulation Join the Therapeutic Armamentarium in Obsessive-Compulsive Disorder?

Feasibility and acceptability of transcranial stimulation in obsessive-compulsive symptoms (FEATSOCS): study protocol for a randomised controlled trial of transcranial direct current stimulation (tDCS) in obsessive-compulsive disorder (OCD)

Background

Obsessive–compulsive disorder (OCD) is a neuropsychiatric disorder which often proves refractory to current treatment approaches. Transcranial direct current stimulation (tDCS), a noninvasive form of neurostimulation, with potential for development as a self-administered intervention, has shown potential as a safe and efficacious treatment for OCD in a small number of trials. The two most promising stimulation sites are located above the orbitofrontal cortex (OFC) and the supplementary motor area (SMA).

Methods

The aim of this feasibility study is to inform the development of a definitive trial, focussing on the acceptability, safety of the intervention, feasibility of recruitment, adherence and tolerability to tDCS and study assessments and the size of the treatment effect. To this end, we will deliver a double-blind, sham-controlled, crossover randomised multicentre study in 25 adults with OCD. Each participant will receive three courses of tDCS (SMA, OFC and sham), randomly allocated and given in counterbalanced order. Each course comprises four 20-min stimulations, delivered over two consecutive days, separated by at least 4 weeks’ washout period. We will collect information about recruitment, study conduct and tDCS delivery. Blinded raters will assess clinical outcomes before, during and up to 4 weeks after stimulation using validated scales. We will include relevant objective neurocognitive tasks, testing cognitive flexibility, motor disinhibition, cooperation and habit learning.

Discussion

We will analyse the magnitude of the effect of the interventions on OCD symptoms alongside the standard deviation of the outcome measure, to estimate effect size and determine the optimal stimulation target. We will also measure the duration of the effect of stimulation, to provide information on spacing treatments efficiently. We will evaluate the usefulness and limitations of specific neurocognitive tests to determine a definitive test battery. Additionally, qualitative data will be collected from participants to better understand their experience of taking part in a tDCS intervention, as well as the impact on their overall quality of life. These clinical outcomes will enable the project team to further refine the methodology to ensure optimal efficiency in terms of both delivering and assessing the treatment in a full-scale trial.

Trial registration

ISRCTN17937049. (date applied 08/07/2019).

Recruitment (ongoing) began 23rd July 2019 and is anticipated to complete 30th April 2021.

Obsessive-Compulsive Disorders

PURPOSE OF REVIEW

This article describes the phenomenology and clinical presentation of obsessive-compulsive disorder (OCD), a common but underdiagnosed psychiatric disorder. Guidance for effectively identifying obsessive-compulsive symptoms is provided, and treatment options, including psychotherapy, pharmacologic management, and neuromodulation approaches for treatment-resistant OCD, are discussed.

RECENT FINDINGS

OCD affects 2% to 3% of adults worldwide and is associated with substantial individual disability and societal costs. Lack of recognition of common OCD symptom types, in addition to shame and fear of stigma on the part of patients, has created an average delay in diagnosis by almost 10 years and a delay in effective treatment (ie, a treatment gap) of nearly 2 years. Cognitive-behavioral therapy (CBT), specifically a form of CBT that includes a type of behavioral intervention called exposure and response prevention, remains the most effective form of treatment for OCD. If CBT is not effective or not available, pharmacologic treatment with selective serotonin reuptake inhibitors (SSRIs) or clomipramine, a nonselective serotonin reuptake inhibitor, can also be of benefit. Neuromodulation approaches such as deep brain stimulation and transcranial magnetic stimulation are rapidly emerging as effective treatments for OCD, particularly for patients who have not experienced an adequate response to psychotherapy or pharmacologic management.

SUMMARY

OCD affects more than one in every 50 adults in the United States but is recognized and adequately treated in fewer than half of those affected. Early intervention and appropriate treatment can substantially reduce OCD symptom severity, improve quality of life, and minimize the functional disability associated with this chronic and often debilitating illness.

Transcranial direct current stimulation for treatment-resistant obsessive-compulsive disorder-A large case series

OBJECTIVE

The present study is a large case series evaluating the benefits of transcranial direct current stimulation (tDCS) in treatment-resistant obsessive compulsive disorder (OCD).

METHODS

We reviewed the charts of 32 patients with treatment-resistant OCD who received 10-20 sessions of anodal pre-SMA tDCS.

RESULTS

Overall, 9 (28 %) showed at least partial response to tDCS at the end of 10-20 sessions [responders = 8 (25 %), partial responders = 1 (3%)]. Two out of three partial responders at the end of 10 sessions had response at the end of 20 sessions.

CONCLUSIONS

tDCS may benefit a proportion of patients with treatment-resistant OCD.