Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (917 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
An anxiety disorder characterized by recurrent, persistent obsessions or compulsions. Obsessions are the intrusive ideas, thoughts, or images that are experienced as senseless or repugnant. Compulsions are repetitive and seemingly purposeful behavior which the individual generally recognizes as senseless and from which the individual does not derive pleasure although it may provide a release from tension.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Disorder, Obsessive-Compulsive; Disorders, Obsessive-Compulsive; Obsessive Compulsive Disorder; Obsessive-Compulsive Disorders; Anankastic Personality; Anankastic Personalities; Personalities, Anankastic; Personality, Anankastic.
Where it fits in the MeSH classification
- Broader topics
- Anxiety Disorders
- Narrower topics
- Excoriation Disorder; Hoarding Disorder; Trichotillomania
Research landscape
PubMed indexes 19,505 records tagged with the MeSH heading “Obsessive-Compulsive Disorder” (counts retrieved 2026-10-31). 4,196 of them (21.5%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 5,720 records.
Reviews account for 3,200 records (16.4%) and meta-analyses for 483. Randomized controlled trials number 954 (4.9%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 5,321 |
| 2000-2009 | 4,268 |
| 2010-2019 | 5,720 |
| 2020 onward | 4,196 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 3,200 | 16.4% |
| Meta-analyses | 483 | 2.5% |
| Randomized controlled trials | 954 | 4.9% |
Method: PubMed query "Obsessive-Compulsive Disorder"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in psychiatry and psychology
Research on mental health and behaviour relies on questionnaires, interviews and rating scales rather than physical measurements, so how a condition was defined and measured shapes every result. Many studies are observational or small, placebo responses can be large, and findings in one group or culture may not carry over to another. Nothing on this page is advice about diagnosis or treatment; anyone worried about their mental health should talk to a qualified clinician. Check how outcomes were measured, who took part and how long they were followed.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder | 2025 | Meta-analysis Design not recorded in structured metadata | 80 | cc by PMID 40360802 · DOI · PMC12165847 |
| A burden of rare copy number variants in obsessive-compulsive disorder | 2025 | Research article Design not recorded in structured metadata | 23 | cc by PMID 39463448 · DOI · PMC11919692 |
| Obsessive-compulsive disorder in the World Mental Health surveys | 2025 | Research article Design not recorded in structured metadata | 21 | cc by PMID 40629326 · DOI · PMC12239380 |
| Indecision and recency-weighted evidence integration in non-clinical and clinical settings | 2026 | Research article Design not recorded in structured metadata | 5 | cc by PMID 41565988 · DOI · PMC13121037 |
Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Obsessive-compulsive disorder (OCD) affects ~1% of children and adults and is partly caused by genetic factors.
- Closing excerpt
- In particular, OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome and was negatively associated with inflammatory bowel diseases, educational attainment and body mass index.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (156 words)
Obsessive-compulsive disorder (OCD) affects ~1% of children and adults and is partly caused by genetic factors. We conducted a genome-wide association study (GWAS) meta-analysis combining 53,660 OCD cases and 2,044,417 controls and identified 30 independent genome-wide significant loci. Gene-based approaches identified 249 potential effector genes for OCD, with 25 of these classified as the most likely causal candidates, including WDR6, DALRD3 and CTNND1 and multiple genes in the major histocompatibility complex (MHC) region. We estimated that ~11,500 genetic variants explained 90% of OCD genetic heritability. OCD genetic risk was associated with excitatory neurons in the hippocampus and the cortex, along with D1 and D2 type dopamine receptor-containing medium spiny neurons. OCD genetic risk was shared with 65 of 112 additional phenotypes, including all the psychiatric disorders we examined. In particular, OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome and was negatively associated with inflammatory bowel diseases, educational attainment and body mass index.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40360802 · DOI · PMC12165847
A burden of rare copy number variants in obsessive-compulsive disorder [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Current genetic research on obsessive-compulsive disorder (OCD) supports contributions to risk specifically from common single nucleotide variants (SNVs), along with rare coding SNVs and small insertion-deletions (indels).
- Closing excerpt
- The results demonstrate a contribution of rare CNVs to OCD risk, and suggest that studies of rare coding variation in OCD would have increased power to identify risk genes if this class of variation were incorporated into formal tests.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (266 words)
Current genetic research on obsessive-compulsive disorder (OCD) supports contributions to risk specifically from common single nucleotide variants (SNVs), along with rare coding SNVs and small insertion-deletions (indels). The contribution to OCD risk from rare copy number variants (CNVs), however, has not been formally assessed at a similar scale. Here we describe an analysis of rare CNVs called from genotype array data in 2248 deeply phenotyped OCD cases and 3608 unaffected controls from Sweden and Norway. Cases carry an elevated burden of CNVs ≥30 kb in size (OR = 1.12, P = 1.77 × 10-3). The excess rate of these CNVs in cases versus controls was around 0.07 (95% CI 0.02-0.11, P = 2.58 × 10-3). This signal was largely driven by CNVs overlapping protein-coding regions (OR = 1.19, P = 3.08 × 10-4), particularly deletions impacting loss-of-function intolerant genes (pLI >0.995, OR = 4.12, P = 2.54 × 10-5). We did not identify any specific locus where CNV burden was associated with OCD case status at genome-wide significance, but we noted non-random recurrence of CNV deletions in cases (permutation P = 2.60 × 10-3). In cases where sufficient clinical data were available (n = 1612) we found that carriers of neurodevelopmental duplications were more likely to have comorbid autism (P < 0.001), and that carriers of deletions overlapping neurodevelopmental genes had lower treatment response (P = 0.02). The results demonstrate a contribution of rare CNVs to OCD risk, and suggest that studies of rare coding variation in OCD would have increased power to identify risk genes if this class of variation were incorporated into formal tests.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39463448 · DOI · PMC11919692
Obsessive-compulsive disorder in the World Mental Health surveys [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundNational surveys have suggested that obsessive-compulsive disorder (OCD) is a prevalent and impairing condition.
- Closing excerpt
- ConclusionsThese cross-national data underscore clinical lessons regarding the importance of early diagnosis of OCD and comprehensive evaluation of comorbidity; draw attention to OCD as an undertreated disorder, particularly in LMIC contexts; and emphasize the public health significance of this often-overlooked condition.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (339 words)
BackgroundNational surveys have suggested that obsessive-compulsive disorder (OCD) is a prevalent and impairing condition. However, there are few cross-national data on OCD, with data particularly scarce in low- and middle-income countries. Here we employ data from the World Mental Health surveys to characterize the onset, course, severity, and treatment of OCD across a range of countries in different geographic regions of the world.MethodsData came from general population surveys carried out in 10 countries (Argentina, Australia, Colombia, Iraq, Poland, People's Republic of China, Portugal, Romania, Saudi Arabia, Spain) using a consistent research protocol and interview. A total of 26,136 adults were assessed for OCD in face-to-face interviews and were included in the present analyses. We examined lifetime and 12-month prevalence as well as age of onset, persistence, severity, and treatment of DSM-IV OCD in six high-income countries (HICs) and four low- or middle-income countries (LMICs). We also investigated socio-demographic variables and temporally prior mental disorders as predictors of OCD onset, persistence, severity, and treatment.ResultsAcross the 10 countries surveyed, OCD has a combined lifetime prevalence of 4.1%. The 12-month prevalence (3.0%) is nearly as high, suggesting a highly persistent course of illness. Age of onset is early, with more than 80% of OCD cases beginning by early adulthood. Most OCD cases in the community are mild (47.0%) or very mild (27.5%), with a smaller percentage designated as moderate (22.9%) or severe (2.7%) by the Yale-Brown Obsessive-Compulsive Scale. Only 19.8% of respondents with OCD received any mental health treatment in the past year, with treatment rates much higher in HICs (40.5%) than LMICs (7.0%). Cross-nationally, OCD commonly emerges in adolescence or early adulthood against a backdrop of earlier-occurring mental disorders. With few exceptions (e.g., prior social phobia), the socio-demographic and psychopathological risk factors for OCD onset, persistence, severity, and treatment are distinct.ConclusionsThese cross-national data underscore clinical lessons regarding the importance of early diagnosis of OCD and comprehensive evaluation of comorbidity; draw attention to OCD as an undertreated disorder, particularly in LMIC contexts; and emphasize the public health significance of this often-overlooked condition.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40629326 · DOI · PMC12239380
Indecision and recency-weighted evidence integration in non-clinical and clinical settings [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Biases in information gathering are common in the general population and reach pathological extremes in paralysing indecisiveness, as in obsessive-compulsive disorder (OCD).
- Closing excerpt
- Our findings establish biased information weighting as a driver of information gathering, where attenuated ΔES is linked to indecisiveness across an obsessive-compulsive spectrum.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (156 words)
Biases in information gathering are common in the general population and reach pathological extremes in paralysing indecisiveness, as in obsessive-compulsive disorder (OCD). Here we adopt a new perspective on information gathering and demonstrate an information integration bias whereby there is over-weighting of most recent information via evidence strength updates (ΔES). In a crowd-sourced sample (N = 5,237), we find that a reduced ΔES weighting drives indecisiveness along an obsessive-compulsive spectrum. We replicate this attenuated ΔES weighting in a second lab-based study (N = 105) that includes a transdiagnostic obsessive-compulsive spectrum encompassing OCD and generalized anxiety patients. Using magnetoencephalography (MEG), we trace ΔES signals to a late neural signal peaking at ~920 ms. Critically, highly obsessive-compulsive participants, across diagnoses, show an attenuated neural ΔES signal in mediofrontal areas, while other decision-relevant processes remain intact. Our findings establish biased information weighting as a driver of information gathering, where attenuated ΔES is linked to indecisiveness across an obsessive-compulsive spectrum.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41565988 · DOI · PMC13121037
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Age at onset of mental disorders worldwide: large-scale meta-analysis of 192 epidemiological studies [5]
- Research article Revealing the complex genetic architecture of obsessive-compulsive disorder using meta-analysis [6]
- Research article Cognitive behavioral therapy for anxiety and related disorders: A meta-analysis of randomized placebo-controlled trials [7]
- Research article Structural and Functional Brain Abnormalities in Attention-Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder: A Comparative Meta-analysis [8]
- Research article Cognitive behavioral treatments of obsessive-compulsive disorder. A systematic review and meta-analysis of studies published 1993-2014 [9]
- Research article The neuropsychology of adult obsessive-compulsive disorder: a meta-analysis [10]
Full-text reviews on EvidenceLib
Open-access review articles about this topic, reproduced in full with authors, licence and references.
A Systematic Review on TeleMental Health in Youth Mental Health: Focus on Anxiety, Depression and Obsessive-Compulsive Disorder
Laura Orsolini, Simone Pompili, Virginio Salvi et al. · Medicina 2021 · CC BY 4.0
References
- Strom NI, Gerring ZF, Galimberti M, Yu D, Halvorsen MW, Abdellaoui A, et al.. Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder. . 2025. PMID 40360802 · DOI · PMC12165847
- Halvorsen MW, de Schipper E, Bäckman J, Strom NI, Hagen K, Nordic OCD and Related Disorders Consortium (NORDiC), et al.. A burden of rare copy number variants in obsessive-compulsive disorder. . 2025. PMID 39463448 · DOI · PMC11919692
- Stein DJ, Ruscio AM, Altwaijri Y, Chiu WT, Sampson NA, Aguilar-Gaxiola S, et al.. Obsessive-compulsive disorder in the World Mental Health surveys. . 2025. PMID 40629326 · DOI · PMC12239380
- Del Río M, Trudel N, Prabhu G, Hunt LT, Moutoussis M, Dolan RJ, et al.. Indecision and recency-weighted evidence integration in non-clinical and clinical settings. . 2026. PMID 41565988 · DOI · PMC13121037
- Solmi M, Radua J, Olivola M, Croce E, Soardo L, Salazar de Pablo G, et al.. Age at onset of mental disorders worldwide: large-scale meta-analysis of 192 epidemiological studies. Mol Psychiatry. 2022. PMID 34079068 · DOI · PMC8960395
- International Obsessive Compulsive Disorder Foundation Genetics Collaborative (IOCDF-GC) and OCD Collaborative Genetics Association Studies (OCGAS). Revealing the complex genetic architecture of obsessive-compulsive disorder using meta-analysis. Mol Psychiatry. 2018. PMID 28761083 · DOI · PMC6660151
- Carpenter JK, Andrews LA, Witcraft SM, Powers MB, Smits JAJ, Hofmann SG. Cognitive behavioral therapy for anxiety and related disorders: A meta-analysis of randomized placebo-controlled trials. Depress Anxiety. 2018. PMID 29451967 · DOI · PMC5992015
- Norman LJ, Carlisi C, Lukito S, Hart H, Mataix-Cols D, Radua J, et al.. Structural and Functional Brain Abnormalities in Attention-Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder: A Comparative Meta-analysis. JAMA Psychiatry. 2016. PMID 27276220 · DOI
- Öst LG, Havnen A, Hansen B, Kvale G. Cognitive behavioral treatments of obsessive-compulsive disorder. A systematic review and meta-analysis of studies published 1993-2014. Clin Psychol Rev. 2015. PMID 26117062 · DOI
- Abramovitch A, Abramowitz JS, Mittelman A. The neuropsychology of adult obsessive-compulsive disorder: a meta-analysis. Clin Psychol Rev. 2013. PMID 24128603 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.