Prevalence and clinical correlates of obsessive-compulsive disorder in central nervous system autoimmune demyelinating diseases: A cross-sectional observational Study

Abstract

Background Obsessive-compulsive disorder (OCD) is a disabling psychiatric comorbidity that may be underrecognized in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). Evidence regarding its prevalence and associated factors in these populations remains limited.Objectives To estimate the prevalence of OCD and examine its clinical and demographic correlates in patients with MS and NMOSD in an Iranian cohort.Design Cross-sectional observational study.Methods This cross-sectional study (January 2018-December 2024) included patients with MS and NMOSD from Kashani Hospital and Hakim MS Clinic, Isfahan, Iran. MS and NMOSD diagnoses were made according to the 2017 McDonald and 2015 IPND criteria, respectively. OCD was diagnosed by certified psychiatrists per DSM-IV. Demographic, clinical, and neuropsychological data were extracted from interviews and medical records. Group comparisons were performed using t-tests or chi 2 tests, followed by univariate and multivariate logistic regression analyses.Results Of 4,759 patients (mean age, 42.9 years; 77.1 female), 4,460 had MS (3,502 with relapsing-remitting MS (RRMS), 212 with primary progressive MS (PPMS), and 746 with secondary progressive MS (SPMS)), and 299 had NMOSD. OCD prevalence was 15.4 in MS, highest in RRMS (17.8), and 12.7 in NMOSD. Across all participants, female sex (OR 1.32, 95 CI 1.04-1.64), higher educational attainment, sensory vs. motor onset symptoms, migraine (OR 1.46, 95 CI 1.16-1.83), and hypothyroidism (OR 1.29, 95 CI 1.01-1.65), lower EDSS (OR per 1-unit: 0.78, 95 CI 0.70 - 0.88), and shorter disease duration (OR per 1-year: 0.98, 95 CI 0.97 - 1.00) were significantly associated with higher odds of OCD.Conclusion OCD is frequently observed among patients with MS and NMOSD and shows distinct clinical associations, including migraine, hypothyroidism, sensory onset phenotype, and lower disability. Recognition of psychiatric comorbidities in these disorders may facilitate more comprehensive and individualized clinical management.