Infections and obsessive-compulsive disorder - results from a systematic review and meta-analysis

Introduction Obsessive-compulsive disorder (OCD) is a psychiatric affecting 1.3% of the population worldwide where both genetic and environmental factors, such as perinatal events neuroinflammation, are thought to contribute etiology disorder. In past, description clinical entities Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infections (PANDAS), in which an acute neuropsychiatric syndrome prominent obsessive-compulsive features emerges children infected group-A beta-hemolytic streptococcus (GABHS), sparked hypothesis that infections may be risk-modifying factor for development OCD. Along streptococcal infections, other pathogens Toxoplasma gondii have been implicated pathophysiological models disorder, although causal associations not established any beforementioned pathogens. Objectives To perform systematic review meta-analysis about presence biological evidence infection patients diagnosed Methods We conducted (PROSPERO registration CRD42021223415) by performing standardized electronic database search MEDLINE/PubMed, Web Science, Embase Scopus. Search was on 17/10/2022. Eligible papers included case-control cohort studies using comparator group, tested specific biomarkers providing OCD; exclusion criteria without quantitative or qualitative measures infection, case reports, scope reviews, animal studies. Selection process according PRISMA 2020 statement guidelines. Study quality assessed through Newcastle-Ottawa Quality Assessment Scale. Results identified 8911 records after duplicate removal. A total 22 met inclusion selection process, 15 were eligible meta-analysis. Most concerned (10 studies), OCD appear higher odds being compared controls, meta-analytic ratio 2.39 (95% IC 1.60-3.58), when comparing 467 5411 controls. However, most methodologically heterogeneous, compromises interpretation results. Information regarding agents, including GABHS, Borna disease virus Toxocara canis gathered but due insufficient number it possible each them. Conclusions Our work suggests albeit exhaustively reported literature, there no strong over-representation control volunteers. Methodologically robust needed further test this hypothesis. Disclosure Interest None Declared