Abstract
Background. Obsessive-compulsive disorder (OCD) is among the top ten causes of disability worldwide and shows a rising incidence under prolonged psychosocial stress conditions, including war-related trauma. Traditional psychopharmacotherapy is often limited by adverse effects and treatment resistance. The endocannabinoid system (ECS) has emerged as a potential neurobiological target in OCD pathogenesis, and medical cannabis (MC) preparations are being explored as a possible adjunctive or alternative therapy. Aim: to systematically evaluate current evidence on the efficacy and safety of medical cannabis preparations in the treatment of OCD, taking into account the role of ECS as a therapeutic target. Materials and methods. We included peer-reviewed systematic reviews, meta-analyses, randomized controlled trials (RCTs), preclinical studies, clinical case reports, and observational studies published from 2019 to 2024 in English or Ukrainian, with available full texts and relevant outcomes on MC use in OCD. A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar. Ukrainian national legislation and WHO publications were also reviewed. The last search date was January 25, 2025. No formal risk of bias assessment tools (e.g. GRADE, Cochrane RoB) were applied due to heterogeneity of study types. Methodological limitations were considered during narrative synthesis. Results. Fifty studies were included. Evidence from preclinical models, case reports, and limited RCTs suggests that MC preparations - especially cannabidiol (CBD) - may reduce OCD symptoms, including intrusive thoughts, compulsive behaviors, anxiety, and sleep disturbances. Positive outcomes were more pronounced when MC was used as adjunct therapy to SSRIs and CBT. Adverse effects were typically mild and transient; however, heterogeneity in dosage, administration, and patient selection limits the generalizability of findings. The main limitations of the included studies are small sample sizes, lack of standardization in dosing and outcome measures, and a shortage of high-quality, large-scale RCTs. Most data were derived from international contexts with limited relevance to Ukrainian clinical practice. Conclusion. MC preparations show potential in alleviating OCD symptoms, likely through ECS modulation. However, conclusive recommendations require further multicenter, controlled studies with standardized protocols and long-term safety evaluations