Gastroenteritis exposure and the risk of schizophrenia onset: A systematic review and meta-analysis

The association between gastroenteritis exposure and schizophrenia (SCZ) onset has been investigated, but the findings were inconsistent. This study aimed to determine whether gastroenteritis would increase the risk of SCZ onset.

We performed a systematic literature search in PubMed, Cochrane Library and the Web of Science database up to 23 November 2019. The pooled relative risk (RR) with 95% confidence interval (CI) was used to estimate the effect of gastroenteritis on SCZ. Stratified analysis was conducted by study design, diagnostic criteria, region, adjustment for confounders, gastroenteritis sub-classification and data source.

This meta-analysis included nine published articles with 13,830,871 subjects. Overall, there was no significant relationship between gastroenteritis and SCZ onset (N [number of studies] = 11, RR = 1.06, 95% CI: 0.81-1.39). However, pooled results from cohort studies suggested that gastroenteritis significantly increased the risk of SCZ (N = 7, RR = 1.27, 95% CI = 1.05-1.53). Increased risk of SCZ was observed in America (N = 3) and Australia (N = 2), whereas no association was found in Europe (N = 1) and Asia (N = 5). The pooled RR, adjusting for ≥2 confounders (N = 5), was higher than those adjusting for <2 confounders (N = 6). The effects also varied in diagnostic criteria, gastroenteritis sub-classification and data source.

Based on current research evidence, it is not yet certain that gastroenteritis is a risk factor for SCZ, and more research on the association between specific gastroenteritis and SCZ is needed.