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

OBJECTIVE: 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. METHOD: 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. RESULT: 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. CONCLUSION: 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.

Task fMRI studies investigating inhibitory control in patients with obsessive-compulsive disorder and eating disorders: A comparative meta-analysis.

BACKGROUND: Obsessive-compulsive disorder (OCD) and eating disorders (EDs) share similarities in terms of clinical characteristics and deficits in inhibitory control. OBJECTIVE: To investigate whether inhibitory control could serve as a common behavioural phenotype between OCD and EDs and whether it might be underpinned by shared and/or distinct neural signatures. METHOD: We performed a quantitative meta-analysis of brain function abnormalities during the inhibitory control task-based functional Magnetic Resonance Imaging (fMRI) scan across patients with OCD and EDs using seed-based d mapping (SDM). RESULTS: The meta-analysis included sixteen OCD fMRI studies and ten EDs fMRI studies. And findings revealed that patients with OCD showed hypoactivation relative to healthy controls and patients with EDs in the anterior cingulate cortex, while compared to healthy controls and patients with OCD, patients with EDs showed hypoactivation in the right insula. CONCLUSIONS: Patients with OCD and EDs are inclined to exhibit impaired inhibitory control, which may be attributed to different abnormal patterns of neural activation.

Comparison of internet-based and face-to-face cognitive behavioral therapy for obsessive-compulsive disorder: A systematic review and network meta-analysis.

Cognitive behavioral therapy (CBT) is widely recognized as an effective treatment for obsessive-compulsive disorder (OCD). However, few patients are able to receive CBT. Internet-based CBT (ICBT) may be able to overcome this problem. In this study, we aimed to compare the efficacy of CBT, therapist-guided ICBT (TG-ICBT), unguided ICBT (UG-ICBT), and none therapist-guided ICBT (NTG-ICBT) by a network meta-analysis. The primary outcome was the mean change in OCD severity measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) or the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). The secondary outcomes included the severity of depressive symptoms, side effects, and cost-effectiveness. A total of 25 trials with 1642 participants were included. We found that the efficacy of CBT was superior to that of TG-ICBT. The mean improvement in Y-BOCS/CY-BOCS scores was higher in CBT group than in UG-ICBT group, but this difference was not statistically significant. The efficacy did not differ significantly between TG-ICBT and UG-ICBT. CBT, TG-ICBT, and UG-ICBT were all more effective than the psychological placebo, waiting list, and pill placebo. In terms of efficacy, CBT combined with drug therapy was better than CBT, TG-ICBT, and UG-ICBT. Sensitivity analyses supported these findings. Based on the current evidence, we recommend TG-ICBT when CBT is not available. However, it is undeniable that UG-ICBT also has the potential to be an effective alternative to CBT. More evidence is needed to support this possibility.

A Systematic Review of Treatment Outcome Predictors in Deep Brain Stimulation for Refractory Obsessive-Compulsive Disorder.

Obsessive-compulsive disorder (OCD) is a chronic and debilitating mental disorder. Deep brain stimulation (DBS) is a promising approach for refractory OCD patients. Research aiming at treatment outcome prediction is vital to provide optimized treatments for different patients. The primary purpose of this systematic review was to collect and synthesize studies on outcome prediction of OCD patients with DBS implantations in recent years. This systematic review (PROSPERO registration number: CRD42022335585) followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines. The search was conducted using three different databases with the following search terms related to OCD and DBS. We identified a total of 3814 articles, and 17 studies were included in our review. A specific tract confirmed by magnetic resonance imaging (MRI) was predictable for DBS outcome regardless of implant targets, but inconsistencies still exist. Current studies showed various ways of successful treatment prediction. However, considering the heterogeneous results, we hope that future studies will use larger cohorts and more precise approaches for predictors and establish more personalized ways of DBS surgeries.