Acceptance and commitment therapy (ACT) for obsessive-compulsive disorder (OCD) has been found efficacious in randomized clinical trials (RCTs), but the two widely known RCTs were conducted within the United States with predominantly White samples. Research that evaluates treatments like ACT for OCD outside the typical Western cultures is needed. The current scoping review summarizes the key characteristics and findings from 18 RCTs that evaluated ACT for OCD in Iran. These RCTs are largely unknown in the broader scientific literature despite representing the vast majority of ACT for OCD trials, in part because the majority are published in Persian. The preponderance of RCTs treated participants in groups, and most protocols did not include exposure exercises. Of 18 trials, 5 were single sex. Use of selective serotonin reuptake inhibitors (SSRIs) was common with all participants on stable doses at pretreatment in many of the trials. Methodological quality was low to medium. ACT was inconsistent against nontraditional comparison conditions, slightly favorable to empirically validated treatments, and favorable compared with the waitlist and SSRIs. The process of change data indicated that ACT increased the psychological flexibility more than cognitive behavior therapy or SSRIs. These results highlight that findings on ACT for OCD from Western populations replicate and generalize to individuals in Iran. These findings also offer insights gained from studying ACT in Iran and significantly expand the literature based on ACT for OCD that can be integrated into scholarship by all researchers.

Objective: To review the literature on the neurobiological mechanisms of obsessive-compulsive symptoms (OCS) in people with dementia.
Data Sources: MEDLINE/PubMed, CENTRAL, and PsycNet databases were searched from inception to March 2023.
Study Selection: Original studies of any methodology with newly published data on the neurobiological underpinnings of OCS in patients with dementia, regardless of patient age or comorbidity and publication year, were included. The following search terms were used: (Obses* OR compul* OR OCD) AND (cognitive de* OR cognitive dysfunction OR cognitive disfunction OR dementia).
Data Extraction: Individual study data were extracted onto a piloted extractions sheet.
Results: Patients with dementia and OCS were reported to have atrophy and hypoperfusion of frontal, temporal, striatal, and limbic structures. Serotonergic agents may be efficacious in reducing OCS. One randomized controlled trial of paroxetine in behavioral symptoms of dementia did not show efficacy. Evidence of dopaminergic dysfunction is too sparse to draw conclusions. Microglia dysfunction mediates obsessive-compulsive-like symptoms. Mutations of microtubule-associated protein τ may increase the risk of OCS. Cognitive self-consciousness and obsessive-compulsive-related cognitions may mediate OCS in old age. Dysfunction of the processing of one class of stimuli may increase the salience of other classes of stimuli, leading to OCS.
Conclusions: Frontal lobe hypometabolism and temporal lobe atrophy and hypometabolism are unexpected given previous research in obsessive compulsive disorder. Serotonergic agents have encouraging efficacy in case reports but require more specific research.
Prim Care Companion CNS Disord 2024;26(3):23r03689.
Author affiliations are listed at the end of this article.

UNASSIGNED: The developmental age, comprising childhood and adolescence, constitutes an extremely important phase of neurodevelopment during which various psychiatric disorders can emerge. Obsessive-Compulsive Disorder (OCD) and Eating Disorders (ED) often manifest during this critical developmental period sharing similarities but also differences in psychopathology, neurobiology, and etiopathogenesis. The aim of this study is to focus on clinical, genetic and neurobiological similarities and differences in OCD and ED.
UNASSIGNED: This study is based on a PubMed/MEDLINE and Cochrane Central Register for Controlled Trial (CENTRAL). The research adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).
UNASSIGNED: The aforementioned search yielded an initial collection of 335 articles, published from 1968 to September 2023. Through the application of inclusion and exclusion criteria, a total of 324 articles were excluded, culminating in a final selection of 10 articles.
UNASSIGNED: Our findings showed both differences and similarities between OCD and ED. Obsessive-compulsive (OC) symptoms are more prevalent in ED characterized by a binge/purge profile than in those with a restrictive profile during developmental age. OC symptomatology appears to be a common dimension in both OCD and ED. When presents, OC symptomatology, exhibits transversal characteristic alterations in the anterior cingulate cortex and poorer cognitive flexibility. These correlations could be highlighted by genetic overlaps between disorders. A comprehensive definition, integrating psychopathological and neurobiological aspects could significantly aid treatment selection and thereby influence the prognosis of these patients.

Obsessive-compulsive disorder (OCD) affects 2-3% of people worldwide. Although antidepressants are the standard pharmachological treatment of OCD, their effect on the brain of individuals with OCD has not yet been fully clarified. We conducted a systematic search on PubMed, Scopus, Embase, and Web of Science to explore the effects of antidepressants on neuroimaging findings in OCD. Thirteen neuroimaging investigations were included. After antidepressant treatment, structural magnetic resonance imaging studies suggested thalamic, amygdala, and pituitary volume changes in patients. In addition, the use of antidepressants was associated with alterations in diffusion tensor imaging metrics in the left striatum, the right midbrain, and the posterior thalamic radiation in the right parietal lobe. Finally, functional magnetic resonance imaging highlighted possible changes in the ventral striatum, frontal, and prefrontal cortex. The small number of included studies and sample sizes, short durations of follow-up, different antidepressants, variable regions of interest, and heterogeneous samples limit the robustness of the findings of the present review. In conclusion, our review suggests that antidepressant treatment is associated with brain changes in individuals with OCD, and these results may help to deepen our knowledge of the pathophysiology of OCD and the brain mechanisms underlying the effects of antidepressants.

BACKGROUND: Trichotillomania (TTM) and excoriation disorder (ED) are impairing obsessive-compulsive related disorders that are common in the general population and for which there are no clear first-line medications, highlighting the need to better understand the underlying biology of these disorders to inform treatments. Given the importance of genetics in obsessive-compulsive disorder (OCD), evaluating genetic factors underlying TTM and ED may advance knowledge about the pathophysiology of these body-focused repetitive behaviors.
OBJECTIVE: In this systematic review, we summarize the available evidence on the genetics of TTM and ED and highlight gaps in the field warranting further research.
METHODS: We systematically searched Embase, PsycInfo, PubMed, Medline, Scopus, and Web of Science for original studies in genetic epidemiology (family or twin studies) and molecular genetics (candidate gene and genome-wide) published up to June 2023.
RESULTS: Of the 3536 records identified, 109 studies were included in this review. These studies indicated that genetic factors play an important role in the development of TTM and ED, some of which may be shared across the OCD spectrum, but there are no known high-confidence specific genetic risk factors for either TTM or ED.
CONCLUSIONS: Our review underscores the need for additional genome-wide research conducted on the genetics of TTM and ED, for instance, genome-wide association and whole-genome/whole-exome DNA sequencing studies. Recent advances in genomics have led to the discovery of risk genes in several psychiatric disorders, including related conditions such as OCD, but to date, TTM and ED have remained understudied.

This study aimed to assess the prevalence of neuropsychiatric sequelae following traumatic brain injury (TBI) among the Western Asian, South Asian and African regions of the global south. All studies on psychiatric disturbances or cognitive impairment following TBI conducted (until August 2021) in the 83 countries that constitute the aforementioned regions were reviewed; 6 databases were selected for the literature search. After evaluating the articles using the Joanna Briggs Institute guidelines, the random effects model was used to estimate the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), TBI-related sleep disturbance (TBI-SD), obsessive-compulsive disorder (OCD) and cognitive impairment. Of 56 non-duplicated studies identified in the initial search, 27 were eligible for systematic review and 23 for meta-analysis. The pooled prevalence of depression in 1,882 samples was 35.35%, that of anxiety in 1,211 samples was 28.64%, that of PTSD in 426 samples was 19.94%, that of OCD in 313 samples was 19.48%, that of TBI-SD in 562 samples was 26.67% and that of cognitive impairment in 941 samples was 49.10%. To date, this is the first critical review to examine the spectrum of post-TBI neuropsychiatric sequelae in the specified regions. Although existing studies lack homogeneous data due to variability in the diagnostic tools and outcome measures utilised, the reported prevalence rates are significant and comparable to statistics from the global north.

BACKGROUND: Multiple sclerosis (MS) is an immune-mediated demyelinating disease with a significant burden of neuropsychiatric sequelae. These symptoms, including depression and anxiety, are predictors of morbidity and mortality in people with MS. Despite a high prevalence of obsessive-compulsive disorder in MS, potentially shared pathophysiological mechanisms and overlap in possible treatments, no review has specifically examined the clinical dimensions of people with obsessive-compulsive and related disorders (OCRD) and MS. In this scoping review, we aim to map the available knowledge on the clinical dimensions of people with co-occurring OCRD and MS. Understanding the characteristics of this population in greater detail will inform more patient-centred care and create a framework for future studies.
METHODS: We developed a search strategy to identify all articles that include people with co-occurring OCRD and MS. The search strategy (extending to the grey literature) was applied to MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science and ProQuest Dissertations & Theses. Records will undergo title and abstract screening by two independent reviewers. Articles meeting inclusion criteria based on title and abstract screening will go on to full-text review by the two independent reviewers. After reaching a consensus about articles for inclusion in the final review, data will be extracted using a standardised extraction form. The extracted data will include clinical characteristics of patients such as age, gender, medication use and severity of MS, among others.
BACKGROUND: This scoping review does not require research ethics approval. Results will be shared at national and/or international conferences, in a peer-reviewed journal publication, in a plain language summary and in a webinar for the general public.

Obsessive-compulsive disorder (OCD) is a common mental health condition characterized by distressing, intrusive thoughts (obsessions) and repetitive behaviours (compulsions) aimed at reducing anxiety. Internet-based cognitive behavioural therapy (ICBT) has emerged as an effective treatment modality for various mental health disorders. This meta-analysis evaluates the efficacy of guided self-help ICBT (GSH ICBT) and unguided self-help ICBT (SH ICBT) against active and passive control conditions in adults with OCD. A comprehensive systematic literature search yielded 12 randomized controlled trials (RCTs) comprising 15 comparison arms (N = 1416) that met the inclusion criteria. Results indicate that GSH ICBT significantly reduced OCD symptomatology posttreatment compared to active controls (g = 0.378, k = 9), with no significant effects maintained at follow-up (g = 0.153, k = 4). GSH ICBT was also found to be as effective as active CBT interventions in reducing comorbid anxiety and depression symptoms posttreatment (g = 0.278, k = 6) and at follow-up (g = 0.124, k = 4). However, improvements in quality of life were not significant posttreatment (g = 0.115, k = 4) nor at follow-up (g = 0.179, k = 3). Combined GSH and SH ICBT demonstrated large effects on reducing OCD symptoms (g = 0.754, k = 6), medium effects on comorbid symptoms (g = 0.547, k = 6) and small effects on quality of life (g = 0.227, k = 2) when compared to inactive controls. No significant differences were found between GSH and SH ICBT in all measured outcomes posttreatment (OCD: g = 0.098, k = 3; AD: g = 0.070, k = 3; QoL: g = -0.030, k = 1) and at follow-up (OCD: g = 0.265, k = 2; AD: g = 0.084, k = 2; QoL: g = 0.00, k = 1). Sample size was identified as a significant moderator of treatment effects. This paper further explores clinical significance, treatment adherence, therapist time investment and moderator influences of the ICBT. The limitations of the study and recommendations for future research are thoroughly discussed.

UNASSIGNED: Cognitive training (CT) for illness-linked neuropsychological deficits has been attempted in psychiatric disorders and, more recently, in obsessive-compulsive disorder (OCD). However, studies are few and far between, with a limited understanding of factors contributing to efficacy. This article aims to provide a comprehensive critical review of studies employing CT in OCD.
UNASSIGNED: This systematic review follows the Preferred Reporting of Items for Systematic Review and Meta-Analyses Protocols. Empirical studies that used any form of CT/remediation in individuals with OCD were included.
UNASSIGNED: Eight articles met the criteria for inclusion, of which five were randomized controlled trials, two were case series, and one was an open-label trial. The studies have predominantly demonstrated improved trained cognitive functions, with only two showing generalization to untrained domains like clinical symptoms and socio-occupational functioning.
UNASSIGNED: There are few controlled trials of CT in OCD, which limits conclusions of efficacy. Given the sparse research in the area, the review summarizes the current status of research and examines important methodological considerations that may inform future studies.

BACKGROUND: This systematic review and meta-analysis explored the relationship between cognitive phenotypes of compulsivity and impulsivity and clinical variables in obsessive-compulsive disorder (OCD).
METHODS: We searched Pubmed, Scopus, Cochrane Library and PsychINFO databases until February 2023 for studies comparing patients with OCD and healthy controls on cognitive tests of compulsivity and impulsivity. The study followed PRISMA guidelines and was pre-registered on PROSPERO (CRD42021299017).
RESULTS: Meta-analyses of 112 studies involving 8313 participants (4289 patients with OCD and 4024 healthy controls) identified significant impairments in compulsivity (g = -0.58, [95%CI -0.68, -0.47]; k = 76) and impulsivity (g = -0.48, [95%CI -0.57, -0.38]; k = 63); no significant difference between impairments. Medication use and comorbid psychiatric disorders were not significantly related to impairments. No associations were revealed with OCD severity, depression/anxiety, or illness duration.
CONCLUSIONS: Cognitive phenotypes of compulsivity and impulsivity in patients with OCD appear to be orthogonal to clinical variables, including severity of OCD symptomatology. Their clinical impact is poorly understood and may require different clinical assessment tools and interventions.