Assessing the effectiveness of high-definition transcranial direct current stimulation for treating obsessive-compulsive disorder: Results from a randomized, double-blind, controlled trial.

Characterized by its disabling nature, obsessive compulsive disorder (OCD) affects individuals profoundly, with nearly 40% of patients showing resistance to initial treatment methods. Despite being safe and easily accessible, transcranial direct current stimulation (tDCS) lacks extensive substantiation supporting its efficacy in treating OCD. The objective of this study was to evaluate how cathodal high-definition transcranial direct current stimulation (HD-tDCS) applied to the right orbitofrontal cortex affected patients with OCD in terms of efficacy. 47 patients with OCD were enrolled. They were randomly allocated to active or sham stimulation groups, and underwent HD-tDCS stimulation treatment for 2 weeks. The central electrode located in the right orbitofrontal cortex region was cathodic. The severity of the patients' obsessive-compulsive symptoms, depression and anxiety were assessed before and after treatment. Out of the total, 44 patients concluded the treatment, comprising 23 participants from the active stimulation group and 21 from the sham stimulation group. Notably, substantial reductions in symptoms related to OCD, depression, and anxiety were exhibited in both groups. With a response rate of 26.1% in the active stimulation group and 23.8% in the sham stimulation group, there was no significant difference in efficacy observed. Furthermore, the reduction in depression and anxiety symptoms at the conclusion of the treatment was not notably superior in the active stimulation group. This study provided evidence for the acceptability and safety of HD-tDCS. Nevertheless, the study did not reveal notable clinical effectiveness of tDCS in addressing moderate to severe OCD in comparison to the sham stimulation group.

Wang Y ，Cheng J ，Ruan H ，Zhang J ，Zheng Z ，Lin L ，Gao J ，Yuan C ，Han H ，Fan Q ，Wang Z ... -  《-》

Efficacy of pre-supplementary motor area transcranial direct current stimulation for treatment resistant obsessive compulsive disorder: A randomized, double blinded, sham controlled trial.

A significant proportion of obsessive compulsive disorder (OCD) patients do not respond to specific serotonin reuptake inhibitors (SSRIs). There is a need to evaluate novel treatment options for OCD. In this double blinded, randomized, sham controlled study, we investigated the efficacy of add-on transcranial direct current stimulation (tDCS) in reducing the symptoms in SSRI-resistant OCD patients by employing anodal pre-supplementary motor area (pre-SMA) stimulation. Twenty-five patients with DSM-IV OCD having persistent symptoms despite adequate and stable treatment with at least one SSRI were randomly allocated to receive 20 min of verum (active) 2-mA tDCS or sham stimulation twice daily on 5 consecutive days [anode over Pre-SMA; cathode over right supra-orbital area]. Response to treatment was defined as at least 35% reduction in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) total score along with a Clinical Global Impression - Improvement (CGI-I) score of 1 (very much improved) or 2 (much improved). The response rate was significantly greater in the verum tDCS(4 out of 12) compared to sham-tDCS (0 out of 13) [Fisher's exact test, p = 0.04]. Repeated measures analysis of variance with tDCS type (verum vs. sham) as between subjects factor showed that there was a significant tDCS-type X time-point interaction with significantly greater reduction of YBOCS total score [F (1,22) = 4.95,p = 0.04,partial-η2 = 0.18] in verum-tDCS group. The results of this RCT suggest that tDCS may be effective in treating SSRI-resistant OCD. Future studies should examine the efficacy in larger samples of OCD and explore other potential target regions using randomized sham-controlled designs, in addition to examining the sustainability of the beneficial effects. Clinical Trials Registry India (http://ctri.nic.in/Clinicaltrials/login.php): Registration Number- CTRI/2016/04/006837).

Gowda SM ，Narayanaswamy JC ，Hazari N ，Bose A ，Chhabra H ，Balachander S ，Bhaskarapillai B ，Shivakumar V ，Venkatasubramanian G ，Reddy YCJ ... -  《-》

Transcranial direct current stimulation in patients with obsessive compulsive disorder: A randomized controlled trial.

Bation R ，Mondino M ，Le Camus F ，Saoud M ，Brunelin J ... -  《-》

The safety and efficacy of transcranial direct current stimulation as add-on therapy to fluoxetine in obsessive-compulsive disorder: a randomized, double-blind, sham-controlled, clinical trial.

Yoosefee S ，Amanat M ，Salehi M ，Mousavi SV ，Behzadmanesh J ，Safary V ，Yoonesi A ，Salehi B ... -  《BMC Psychiatry》

Feasibility, acceptability and practicality of transcranial stimulation in obsessive compulsive symptoms (FEATSOCS): A randomised controlled crossover trial.

Transcranial direct current stimulation (tDCS) is a non-invasive form of neurostimulation with potential for development as a self-administered intervention. It has shown promise as a safe and effective treatment for obsessive compulsive disorder (OCD) in a small number of studies. The two most favourable stimulation targets appear to be the left orbitofrontal cortex (L-OFC) and the supplementary motor area (SMA). We report the first study to test these targets head-to-head within a randomised sham-controlled trial. Our aim was to inform the design of future clinical research studies, by focussing on the acceptability and safety of the intervention, feasibility of recruitment, adherence to and tolerability of tDCS, and the size of any treatment-effect. FEATSOCS was a randomised, double-blind, sham-controlled, cross-over, multicentre study. Twenty adults with DSM-5-defined OCD were randomised to treatment, comprising three courses of clinic-based tDCS (SMA, L-OFC, Sham), randomly allocated and delivered in counterbalanced order. Each course comprised four 20-min 2 mA stimulations, delivered over two consecutive days, separated by a 'washout' period of at least four weeks. Assessments were carried out by raters who were blind to stimulation-type. Clinical outcomes were assessed before, during, and up to four weeks after stimulation. Patient representatives with lived experience of OCD were actively involved at all stages. Clinicians showed willingness to recruit participants and recruitment to target was achieved. Adherence to treatment and study interventions was generally good, with only two dropouts. There were no serious adverse events, and adverse effects which did occur were transient and mostly mild in intensity. Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores were numerically improved from baseline to 24 h after the final stimulation across all intervention groups but tended to worsen thereafter. The greatest effect size was seen in the L-OFC arm, (Cohen's d = -0.5 [95% CI -1.2 to 0.2] versus Sham), suggesting this stimulation site should be pursued in further studies. Additional significant sham referenced improvements in secondary outcomes occurred in the L-OFC arm, and to a lesser extent with SMA stimulation. tDCS was acceptable, practicable to apply, well-tolerated and appears a promising potential treatment for OCD. The L-OFC represents the most promising target based on clinical changes, though the effects on OCD symptoms were not statistically significant compared to sham. SMA stimulation showed lesser signs of promise. Further investigation of tDCS in OCD is warranted, to determine the optimal stimulation protocol (current, frequency, duration), longer-term effectiveness and brain-based mechanisms of effect. If efficacy is substantiated, consideration of home-based approaches represents a rational next step. ISRCTN17937049. https://doi.org/10.1186/ISRCTN17937049.

Fineberg NA ，Cinosi E ，Smith MVA ，Busby AD ，Wellsted D ，Huneke NTM ，Garg K ，Aslan IH ，Enara A ，Garner M ，Gordon R ，Hall N ，Meron D ，Robbins TW ，Wyatt S ，Pellegrini L ，Baldwin DS ... -  《-》