Inflammation in obsessive-compulsive disorder: A literature review and hypothesis-based potential of transcranial photobiomodulation.

Obsessive-compulsive disorder (OCD) is a disabling neuropsychiatric disorder that affects about 2%-3% of the global population. Despite the availability of several treatments, many patients with OCD do not respond adequately, highlighting the need for new therapeutic approaches. Recent studies have associated various inflammatory processes with the pathogenesis of OCD, including alterations in peripheral immune cells, alterations in cytokine levels, and neuroinflammation. These findings suggest that inflammation could be a promising target for intervention. Transcranial photobiomodulation (t-PBM) with near-infrared light is a noninvasive neuromodulation technique that has shown potential for several neuropsychiatric disorders. However, its efficacy in OCD remains to be fully explored. This study aimed to review the literature on inflammation in OCD, detailing associations with T-cell populations, monocytes, NLRP3 inflammasome components, microglial activation, and elevated proinflammatory cytokines such as TNF-α, CRP, IL-1ß, and IL-6. We also examined the hypothesis-based potential of t-PBM in targeting these inflammatory pathways of OCD, focusing on mechanisms such as modulation of oxidative stress, regulation of immune cell function, reduction of proinflammatory cytokine levels, deactivation of neurotoxic microglia, and upregulation of BDNF gene expression. Our review suggests that t-PBM could be a promising, noninvasive intervention for OCD, with the potential to modulate underlying inflammatory processes. Future research should focus on randomized clinical trials to assess t-PBM's efficacy and optimal treatment parameters in OCD. Biomarker analyses and neuroimaging studies will be important in understanding the relationship between inflammatory modulation and OCD symptom improvement following t-PBM sessions.

Mindfulness-based cognitive therapy neurobiology in treatment-resistant obsessive-compulsive disorder: A domain-related resting-state networks approach.

Mindfulness-based cognitive therapy (MBCT) stands out as a promising augmentation psychological therapy for patients with obsessive-compulsive disorder (OCD). To identify potential predictive and response biomarkers, this study examines the relationship between clinical domains and resting-state network connectivity in OCD patients undergoing a 3-month MBCT programme. Twelve OCD patients underwent two resting-state functional magnetic resonance imaging sessions at baseline and after the MBCT programme. We assessed four clinical domains: positive affect, negative affect, anxiety sensitivity, and rumination. Independent component analysis characterised resting-state networks (RSNs), and multiple regression analyses evaluated brain-clinical associations. At baseline, distinct network connectivity patterns were found for each clinical domain: parietal-subcortical, lateral prefrontal, medial prefrontal, and frontal-occipital. Predictive and response biomarkers revealed significant brain-clinical associations within two main RSNs: the ventral default mode network (vDMN) and the frontostriatal network (FSN). Key brain nodes -the precuneus and the frontopolar cortex- were identified within these networks. MBCT may modulate vDMN and FSN connectivity in OCD patients, possibly reducing symptoms across clinical domains. Each clinical domain had a unique baseline brain connectivity pattern, suggesting potential symptom-based biomarkers. Using these RSNs as predictors could enable personalised treatments and the identification of patients who would benefit most from MBCT.

Pallidum volume as a predictor for the effectiveness of mindfulness-based cognitive therapy and psycho-education in unmedicated patients with obsessive-compulsive disorder.

BACKGROUND: Mindfulness-based cognitive therapy (MBCT) has been documented to be effective in treating obsessive-compulsive disorder (OCD). However, the neurobiological basis of MBCT remains largely elusive, which makes it clinically challenging to predict which patients are more likely to respond poorly. Hence, identifying biomarkers for predicting treatment outcomes holds both scientific and clinical values. This prognostic study aims to investigate whether pre-treatment brain morphological metrics can predict the effectiveness of MBCT, compared with psycho-education (PE) as an active placebo, among patients with OCD. METHODS: A total of 32 patients with OCD were included in this prognostic study. They received magnetic resonance imaging (MRI) brain scans before treatment. Subsequently, 16 patients received 10 weeks of MBCT, while the other 16 patients underwent a 10-week PE program. The effectiveness of the treatments was primarily assessed by the reduction rate of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) total score before and after the treatment. We investigated whether several predefined OCD-associated brain morphological metrics, selected based on prior published studies by the ENIGMA Consortium, could predict the treatment effectiveness. RESULTS: Both the MBCT and PE groups exhibited substantial reductions in Y-BOCS scores over 10 weeks of treatment, with the MBCT group showing a larger reduction. Notably, the pallidum total volume was associated with treatment effectiveness, irrespective of the intervention group. Specifically, a linear regression model utilizing the pre-treatment pallidum volume to predict the treatment effectiveness suggested that a one-cubic-centimeter increase in pallidum volume corresponded to a 22.3% decrease in the Y-BOCS total score reduction rate. CONCLUSIONS: Pallidum volume may serve as a promising predictor for the effectiveness of MBCT and PE, and perhaps, other treatments with the shared mechanisms by MBCT and PE, among patients with OCD.

The promise and challenges of transcranial magnetic stimulation and deep brain stimulation as therapeutic options for obsessive-compulsive disorder.

INTRODUCTION: Obsessive compulsive disorder (OCD) represents a complex and often difficult to treat disorder. Pharmacological and psychotherapeutic interventions are often associated with sub-optimal outcomes, and 40-60% of patients are resistant to first line therapies and thus left with few treatment options. OCD is underpinned by aberrant neurocircuitry within cortical, striatal, and thalamic brain networks. Considering the neurocircuitry impairments that underlie OCD symptomology, neurostimulation therapies provide an opportunity to modulate psychopathology in a personalized manner. Also, by probing pathological neural networks, enhanced understanding of disease states can be obtained. AREAS COVERED: This perspective discusses the clinical efficacy of TMS and DBS therapies, treatment access options, and considerations and challenges in managing patients. Recent scientific progress is discussed, with a focus on neurocircuitry and biopsychosocial aspects. Translational recommendations and suggestions for future research are provided. EXPERT OPINION: There is robust evidence to support TMS and DBS as an efficacious therapy for treatment resistant OCD patients supported by an excellent safety profile and favorable health economic data. Despite a great need for alternative therapies for chronic and severe OCD patients, resistance toward neurostimulation therapies from regulatory bodies and the psychiatric community remains. The authors contend for greater access to TMS and DBS for treatment resistant OCD patients at specialized sites with appropriate clinical resources, particularly considering adjunct and follow-up care. Also, connectome targeting has shown robust predictive ability of symptom improvements and holds potential in advancing personalized neurostimulation therapies.

Neural mechanisms of acceptance-commitment therapy for obsessive-compulsive disorder: a resting-state and task-based fMRI study.

BACKGROUND: There is growing evidence for the use of acceptance-commitment therapy (ACT) for the treatment of obsessive-compulsive disorder (OCD). However, few fully implemented ACT have been conducted on the neural mechanisms underlying its effect on OCD. Thus, this study aimed to elucidate the neural correlates of ACT in patients with OCD using task-based and resting-state functional magnetic resonance imaging (fMRI). METHODS: Patients with OCD were randomly assigned to the ACT (n = 21) or the wait-list control group (n = 21). An 8-week group-format ACT program was provided to the ACT group. All participants underwent an fMRI scan and psychological measurements before and after 8 weeks. RESULTS: Patients with OCD showed significantly increased activation in the bilateral insula and superior temporal gyri (STG), induced by the thought-action fusion task after ACT intervention. Further psycho-physiological interaction analyses with these regions as seeds revealed that the left insular-left inferior frontal gyrus (IFG) connectivity was strengthened in the ACT group after treatment. Increased resting-state functional connectivity was also found in the posterior cingulate cortex (PCC), precuneus, and lingual gyrus after ACT intervention Most of these regions showed significant correlations with ACT process measures while only the right insula was correlated with the obsessive-compulsive symptom measure. CONCLUSIONS: These findings suggest that the therapeutic effect of ACT on OCD may involve the salience and interoception processes (i.e. insula), multisensory integration (i.e. STG), language (i.e. IFG), and self-referential processes (i.e. PCC and precuneus). These areas or their interactions could be important for understanding how ACT works psychologically.

Neurofeedback for obsessive compulsive disorder: A randomized, double-blind trial.

We aim to develop fMRI neurofeedback as a treatment for obsessive compulsive disorder (OCD). In prior work, we found that providing neurofeedback of activity in the anterior prefrontal cortex (aPFC) improved control over contamination anxiety in a subclinical population. Here, we present the results of a randomized, double-blind clinical trial (NCT02206945) testing this intervention in patients with OCD. We recruited patients with primary symptoms in the fear-of-harm/checking or contamination/washing domains. During neurofeedback, they viewed symptom provocative images and attempted to up- and down-regulate the aPFC during different blocks of time. The active group received two sessions of neurofeedback and the control group received yoked sham feedback. The primary outcome measure was the Yale-Brown Obsessive-Compulsive Symptom scale. The secondary outcome was control over aPFC. Thirty-six participants completed feedback training (18 active, 18 control). The active group had a slightly but significantly greater reduction of obsessive-compulsive symptoms after neurofeedback compared to the control group (p<.05) but no significant differences in control over the aPFC. These data demonstrate that neurofeedback targeting the aPFC can reduce symptoms in OCD. Future investigations should seek to optimize the training protocol to yield larger effects and to clarify the mechanism of action.

Effectiveness of Internet-delivered self-help acceptance and commitment therapy (iACT) on nurses' obsessive-compulsive symptoms and sleep quality: A randomized controlled trial with 3-month follow-up.

BACKGROUND: Frontline nurses suffered unprecedented mental distress during the COVID-19 pandemic. It's essential to explore new and more accessible alternatives to improve the availability of psychological treatments. This study aimed to investigate the influence of online self-help iACT linear intervention and iACT loop intervention on sleep quality (SQ), obsessive-compulsive symptoms (OCS), and psychological flexibility (PF) in nurses. METHODS: A randomized controlled trial was conducted at a hospital in China. 602 participants were randomly assigned to the iACT linear intervention, iACT loop intervention, or wait list control group, and required to complete the questionnaires of OCS, PF and SQ. The linear mixed effects analysis (LMM) was used to analyze the impact of the intervention on outcome variables. RESULTS: LMM analyses demonstrated that both two intervention had significant improvement on OCS (t = -38.235, p < 0.001), PF (t = 28.156, p < 0.001), as well as SQ (t = -16.336, p < 0.001). There were significant differences between the linear group and loop group on the PF in T2 (t = -8.271, p < 0.001), T3 (t = -8.366, p < 0.001), T4 (t = -8.302, p < 0.001), with the iACT loop model (Cohen's d = 1.652) showing a slight advantage over the iACT linear model (Cohen's d = 1.134). CONCLUSIONS: The findings indicate that two interventions positively impact OCS, PF, and SQ. Compared to the iACT linear psychotherapy model, the iACT loop model shows greater effectiveness in enhancing PF, making it helpful to promote significant improvements in psychotherapy planning.

Walking through the valley of the shadow of death-The psychotherapy of the head and neck cancer patient expressing suicidal ideations and impulses.

The paper aims to show the multilevel and complex cooperation and the inclusion of the psychotherapist leading the psychotherapy in the medical team at the radiotherapy and clinical oncology clinic. We illustrate these interventions with the case of Stan. This 43-year-old firefighter was diagnosed with advanced head and neck cancer and pre-existing mental health problems meeting the criteria of ICD-10: obsessive-compulsive disorder, post-traumatic stress disorder and psychoactive substance abuse. During the treatment, suicidal thoughts and impulses emerged, triggered at the hospital by electronic noises and the feeling of entrapment without a way out. This situation put the patient at high risk and the whole healthcare team needed an urgent effective response. The patient agreed to stay in the secured room, where he was cared for by doctors, nurses, a dietitian, and a psychotherapist. He actively attended daily sessions with noticeable engagement. Psychotherapy sessions focused on alleviating posttraumatic stress disorder and OCD. Mindfulness and breathwork-based exercises were implemented to increase non-judgemental self-awareness and regulate the over-aroused nervous system. As a result, the patient's mental health has improved and the completion of the cancer treatment was possible. Psychotherapy, good therapeutic alliance, and attentive teamwork effectively managed his mental health and treatment-related symptoms.

The Rostral Zona Incerta: A Subcortical Integrative Hub and Potential Deep Brain Stimulation Target for Obsessive-Compulsive Disorder.

BACKGROUND: The zona incerta (ZI) is involved in mediating survival behaviors and is connected to a wide range of cortical and subcortical structures, including key basal ganglia nuclei. Based on these connections and their links to behavioral modulation, we propose that the ZI is a connectional hub for mediating between top-down and bottom-up control and a possible target for deep brain stimulation for obsessive-compulsive disorder. METHODS: We analyzed the trajectory of cortical fibers to the ZI in nonhuman and human primates based on tracer injections in monkeys and high-resolution diffusion magnetic resonance imaging in humans. The organization of cortical and subcortical connections within the ZI were identified in the nonhuman primate studies. RESULTS: Monkey anatomical data and human diffusion magnetic resonance imaging data showed a similar trajectory of fibers/streamlines to the ZI. Prefrontal cortex/anterior cingulate cortex terminals all converged within the rostral ZI, with dorsal and lateral areas being most prominent. Motor areas terminated caudally. Dense subcortical reciprocal connections included the thalamus, medial hypothalamus, substantia nigra/ventral tegmental area, reticular formation, and pedunculopontine nucleus and a dense nonreciprocal projection to the lateral habenula. Additional connections included the amygdala, dorsal raphe nucleus, and periaqueductal gray. CONCLUSIONS: Dense connections with dorsal and lateral prefrontal cortex/anterior cingulate cortex cognitive control areas and the lateral habenula and the substantia nigra/ventral tegmental area, coupled with inputs from the amygdala, hypothalamus, and brainstem, suggest that the rostral ZI is a subcortical hub positioned to modulate between top-down and bottom-up control. A deep brain stimulation electrode placed in the rostral ZI would not only involve connections common to other deep brain stimulation sites but also capture several critically distinctive connections.

Glutamatergic neurotransmission is affected by low-frequency repetitive transcranial magnetic stimulation over the supplemental motor cortex of patients with obsessive-compulsive disorder.

OBJECTIVE: In obsessive-compulsive disorder (OCD), glutamatergic neurotransmission dysfunction played key roles in pathophysiology. The current research assessed changes of neurometabolites in the bilateral striatum of OCD patients receiving low-frequency repetitive transcranial magnetic stimulation (rTMS) using 1H proton magnetic resonance spectroscopy (1H-MRS). METHODS: 52 OCD patients were divided into rTMS treatment group (29) and the control group (medication only) (22). The levels of neurometabolites in the bilateral striatum of patients with OCD were measured using MRS before and after treatment. All participants were taking medication prior to the treatment and the process. RESULTS: Following rTMS treatment, Yale-Brown Obsessive-Compulsive Scale (YBOCS) score was significantly decreased in the rTMS group compared with the control group. Glutamate (Glu) and glutamate and glutamine complexes (Glx) in the bilateral striatum of the rTMS treatment response group increased significantly with the improvement of OCD. Glu in the bilateral striatum and Glx in the right striatum were positively correlated with compulsion after the treatment. CONCLUSIONS: The physiopathological mechanism of OCD may be related to the glutamatergic dysfunction, and the low-frequency repetitive transcranial magnetic stimulation applied to the supplementary motor area can improve OCD symptoms by modulating glutamatergic levels in the bilateral striatum of patients with OCD.

Effectiveness of adjunctive low-frequency repetitive transcranial magnetic stimulation therapy over the left dorsolateral prefrontal cortex in patients with obsessive-compulsive disorder refractory to medical treatment:A double-blind, randomized clinical trial.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a common psychiatric disorder. The Food and Drug Administration (FDA) approved repetitive transcranial magnetic stimulation (rTMS) to treat OCD in 2018. So far, various approaches to treat this disorder have been evaluated. We evaluated the effect of adjunctive low-frequency rtMS over the left dorsolateral prefrontal cortex in patients with OCD refractory to treatment. METHODS: The present clinical trial was done on 37 patients with OCD referring from the psychiatry clinic, 22 Bahman Hospital, Qazvin province, between 2018 and 2020 and patients were randomly divided into two groups. The intervention group received rTMS treatment at 1 Hz for 20 min (1200 pulses/day) over the left DLPFC area as adjunctive to the medical treatment three times a week and for five weeks, whereas those in the control group were subjected to only the sham condition plus their medical treatment. The Yale-Brown Obsessive-Compulsive Scale (Y-BOC.S) was completed by patients before the study, following sessions 5 and 10 during the intervention, at the end of the intervention, and three to six months after the intervention under the direct supervision of a psychiatrist. SPSS software version 26 was used to compare the results between the two groups. RESULTS: The intervention group showed significantly lower mean Y-BOCS scores after the intervention and at follow-up (P < 0.05) and all patients of the intervention group showed significantly lower Y-BOCS scores than their own baseline scores (P < 0.05). Also, using antipsychotic agents along with the serotonergic agents yielded significantly lower scores in the intervention group at the end of the intervention (P < 0.05). All the patients were found with higher follow-up scores than their scores at the end of the intervention; however, this difference was not significant (p > 0.05). CONCLUSION: Adjunctive low-frequency (1 Hz) rTMS over the left DLPFC is able to effectively reduce Y-BOCS score in OCD patients refractory to treatment following 15 sessions, and the reduction was durable even after three to six months. Using antipsychotic agents as an adjuvant with serotonergic agents was identified as a possible predictor for response to adjunctive rTMS therapy.

Family-based cognitive behavioural therapy versus family-based relaxation therapy for obsessive-compulsive disorder in children and adolescents (the TECTO trial): a statistical analysis plan for the randomised clinical trial.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder which affects up to 3% of children and adolescents. OCD in children and adolescents is generally treated with cognitive behavioural therapy (CBT), which, in more severely affected patients, can be combined with antidepressant medication. The TECTO trial aims to compare the benefits and harms of family-based CBT (FCBT) versus family-based psychoeducation/relaxation training (FPRT) in children and adolescents aged 8 to 17 years. This statistical analysis plan outlines the planned statistical analyses for the TECTO trial. METHODS: The TECTO trial is an investigator-initiated, independently funded, single-centre, parallel-group, superiority randomised clinical trial. Both groups undergo 14 sessions of 75 min each during a period of 16 weeks with either FCBT or FPRT depending on the allocation. Participants are randomised stratified by age and baseline Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) score. The primary outcome is the CY-BOCS score. Secondary outcomes are health-related quality of life assessed using KIDSCREEN-10 and adverse events assessed by the Negative Effects Questionnaire (NEQ). Primary and secondary outcomes are assessed at the end of the intervention. Continuous outcomes will be analysed using linear regression adjusted for the stratification variables and baseline value of the continuous outcome. Dichotomous outcomes will be analysed using logistic regression adjusted for the stratification variables. The statistical analyses will be carried out by two independent blinded statisticians. DISCUSSION: This statistical analysis plan includes a detailed predefined description of how data will be analysed and presented in the main publication before unblinding of study data. Statistical analysis plans limit selective reporting bias. This statistical analysis plan will increase the validity of the final trial results. TRIAL REGISTRATION: ClinicalTrials.gov NCT03595098. July 23, 2018.

Meditation-based intervention for obsessive-compulsive disorder: A PRISMA-compliant systematic review and meta-analysis.

BACKGROUND: The purpose of this study was to investigate the effects of the meditation-based intervention on obsessive-compulsive disorder (OCD). METHODS: The following databases were searched up to April 2021: the Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Medline (via PubMed), PsycARTICLES, 4 Korean databases (Korean Medical Database [KMbase], Koreanstudies Information Service System [KISS], National Digital Science Library [NDSL], and Oriental Medicine Advanced Searching Integrated System [OASIS]), and China National Knowledge Infrastructure (CNKI). The search terms related to meditation-based intervention and OCD were used. This systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The selected articles were evaluated using the Cochrane risk of bias tool. The Review Manager (RevMan) 5.4 was used to perform the meta-analysis. RESULTS: In all, 16 randomized controlled trials were selected. The meta-analysis showed that the group receiving the treatment combining medication and meditation-based intervention for OCD showed a more significant post-treatment improvement in Yale-Brown obsessive compulsive scale than the group receiving medication only. Compared with other non-medication interventions that are known to be effective in treating OCD, the Yale-Brown obsessive compulsive scale showed a significant improvement immediately after the meditation-based intervention. However, no significant difference was found in the follow-up monitoring data across all examined cases. CONCLUSION: This study was conducted to verify the effects of meditation-based intervention on OCD. The results suggested that combined treatment with medication and meditation-based intervention was more effective in treating OCD than medication alone; the positive effects of meditation-based intervention may be greater than the effects of other non-medication interventions. However, the lack of significant difference in the follow-up indicates that long-term effect of meditation-based interventions is unclear. TRIAL REGISTRATION NUMBER: PROSPERO CRD42021244408.

Deep brain stimulation in the bed nucleus of the stria terminalis: A symptom provocation study in patients with obsessive-compulsive disorder.

BACKGROUND: Deep brain stimulation (DBS) is an emerging therapy for treatment-resistant obsessive-compulsive disorder (OCD), and several targets for electrode implantation and contact selection have been proposed, including the bed nucleus of the stria terminalis (BST). Selecting the active electrode contacts (patients typically have four to choose from in each hemisphere), and thus the main locus of stimulation, can be a taxing process. Here, we investigated whether contact selection based purely on their neuroanatomical position in the BST is a worthwhile approach. For the first time, we also compared the effects of uni- versus bilateral BST stimulation. METHODS: Nine OCD patients currently receiving DBS participated in a double-blind, randomized symptom provocation study to compare no versus BST stimulation. Primary outcomes were anxiety and mood ratings in response to disorder-relevant trigger images, as well as ratings of obsessions, compulsions, tendency to avoid and overall wellbeing. Furthermore, we asked whether patients preferred the electrode contacts in the BST over their regular stimulation contacts as a new treatment setting after the end of the task. RESULTS: We found no statistically significant group differences between the four conditions (no, left, right and bilateral BST stimulation). Exploratory analyses, as well as follow-up data, did indicate that (bilateral) bipolar stimulation in the BST was beneficial for some patients, particularly for those who had achieved unsatisfactory effects through the typical contact selection procedure. CONCLUSIONS: Despite its limitations, this study suggests that selection of stimulation contacts in the BST is a viable option for DBS in treatment-resistant OCD patients.

Evaluation of Inference-Based Cognitive-Behavioral Therapy for Obsessive-Compulsive Disorder: A Multicenter Randomized Controlled Trial with Three Treatment Modalities.

INTRODUCTION: Inference-based cognitive-behavioral therapy (I-CBT) is a specialized psychological treatment for obsessive-compulsive disorder (OCD) without deliberate and prolonged exposure and response prevention (ERP) that focuses on strengthening reality-based reasoning and correcting the dysfunctional reasoning giving rise to erroneous obsessional doubts and ideas. OBJECTIVE: The present study aimed to evaluate the effectiveness of I-CBT through a comparison with appraisal-based cognitive behavioral therapy (A-CBT) and an adapted mindfulness-based stress reduction (MBSR) intervention. METHODS: This was a two-site, parallel-arm randomized controlled trial (RCT) comparing I-CBT with A-CBT. The MBSR intervention acted as a non-specific active control condition. Following formal evaluation, 111 participants diagnosed with OCD were randomly assigned. The principal outcome measure was the Yale-Brown Obsessive-Compulsive Scale. RESULTS: All treatments significantly reduced general OCD severity and specific symptom dimensions without a significant difference between treatments. I-CBT was associated with significant reductions in all symptom dimensions at post-test. Also, I-CBT led to significantly greater improvement in overvalued ideation, as well as significantly higher rates of remission as compared to MBSR at mid-test. CONCLUSIONS: I-CBT and MBSR appear to be effective, alternative treatment options for those with OCD that yield similar outcomes as A-CBT. I-CBT may have an edge in terms of the rapidity by which patients reach remission, its generalizability across symptom dimension, its potentially higher level of acceptability, and effectiveness for overvalued ideation. Future research is needed to assess whether additional alternative treatments options can help to increase the number of people successfully treated.

Brain Structures and Networks Underlying Treatment Response to Deep Brain Stimulation Targeting the Inferior Thalamic Peduncle in Obsessive-Compulsive Disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a debilitating disease with a lifetime prevalence of 2-3%. Neuromodulatory treatments have been successfully used in severe cases. Deep brain stimulation (DBS) targeting the inferior thalamic peduncle (ITP) has been shown to successfully alleviate symptoms in OCD patients; however, the brain circuits implicated remain unclear. Here, we investigate the efficacious neural substrates following ITP-DBS for OCD. METHODS: High-quality normative structural and functional connectomics and voxel-wise probabilistic mapping techniques were applied to assess the neural substrates of OCD symptom alleviation in a cohort of 5 ITP-DBS patients. RESULTS: The region of most efficacious stimulation was located in the regions of the ITP and bed nucleus of the stria terminalis. Both functional and structural connectomics analyses demonstrated that successful symptom alleviation involved a brain network encompassing the bilateral amygdala and prefrontal regions. LIMITATIONS: The main limitation is the small size of the ITP-DBS cohort. While the findings are highly consistent and significant, these should be validated in larger studies. CONCLUSIONS: These results identify a tripartite brain network - composed of the bilateral amygdala and prefrontal regions 24 and 46 - whose engagement is associated with greater symptom improvement. They also provide information for optimizing targeting and identifying network components critically involved in ITP-DBS treatment response. Amygdala engagement in particular seems to be a key component for clinical benefits and could constitute a biomarker for treatment optimization.

A Systematic Literature Review and Meta-analysis on Effectiveness of Neurofeedback for Obsessive-Compulsive Disorder.

To evaluate the evidences related to the effectiveness of neurofeedback treatment for people with OCD. A literature review and meta-analysis of current controlled trials for patients with OCD symptoms was conducted across different databases. So, the primary outcome measure was OCD symptoms in subjects based on DSM IV. Y-BOCS was considered as primary outcomes. Nine met inclusion criteria (including 1211 patients). Analysis showed there was an important benefit of neurofeedback treatment in comparison to other treatments (MD = -6.815; 95% CI = [-9.033, -4.598]; P < 0.001). The results provide preliminary evidence that NFB is efficacious method for OCD and suggest that more clinical trials are needed to compare common treatment such as medication, neurological, and behavioral interventions.