Stein, Dan J.Ruscio, Ayelet MeronAltwaijri, YasminChiu, Wai TatSampson, Nancy A.Aguilar-Gaxiola, SergioAl-Hamzawi, AliAlonso, JordiChardoul, StephanieGureje, OyeHu, ChiyiKaram, Elie G.McGrath, John J.Navarro-Mateu, FernandoScott, Kate M.Stagnaro, Juan CarlosTorres, YolandaVladescu, CristianWciórka, JacekXavier, MiguelXavier, MiguelKessler, Ronald C.2025-08-012025-08-012025-07-091741-7015PURE: 123113968PURE UUID: 9c5953b9-2d90-4271-85de-27cb0ea3f2a7Scopus: 105010975159PubMed: 40629326http://hdl.handle.net/10362/185923Publisher Copyright: © 2025. The Author(s).BACKGROUND: National 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. METHODS: Data 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. RESULTS: Across 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. CONCLUSIONS: These 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.11049881engCommunity epidemiologyGlobal mental healthObsessive-compulsive disorderWorld Mental Health surveysGeneral MedicineSDG 3 - Good Health and Well-beingjournal article10.1186/s12916-025-04209-5https://www.scopus.com/pages/publications/105010975159