Association between autoimmune diseases of the nervous system and schizophrenia: A systematic review and meta-analysis of cohort studies

Numerous studies have found an association between autoimmune diseases of the nervous system (ADNS) and schizophrenia (SCZ), but the findings remain controversial. We conducted the first meta-analysis to summarize the current evidence from cohort studies that evaluated the association between ADNS and SCZ.PubMed, Web of Science, and Embase were comprehensively searched until May 30, 2022 for articles on the association between ADNS and SCZ. Every included study was reported effect size with 95% CIs for the association between ADNS and SCZ. Meta-regression and subgroup analysis were used to assess the heterogeneity.A total of 8 cohort studies with 12 cohorts were included in the meta-analysis. We observed a significant association between ADNS and SCZ (RR = 1.42; 95%CI, 1.18-1.72). Subgroup analysis showed that the risk of SCZ was significantly increased when ADNS were used as exposure factors (RR = 1.48; 95%CI, 1.15-1.89), whereas with SCZ did not observe an increased risk of subsequent ADNS (RR = 1.33; 95%CI, 0.92-1.92); multiple sclerosis (MS) was positively associated with SCZ (RR = 1.36; 95%CI, 1.12-1.66), but no significant association was found between Guillain-Barre syndrome (GBS) and SCZ (RR = 1.90; 95%CI, 0.87-4.17). Meanwhile, we found location was the source of heterogeneity.High heterogeneity was observed (I2 = 92.0%), and only English literature was included in the meta-analysis.We found a positive association between ADNS and SCZ, and the association was different across the different types of ADNS. The results of the study are helpful for clinicians to carry out targeted preventive measures for ADNS and SCZ.