Among the biomarkers examined, psychotic disorders were associated with elevated CSF-to-serum albumin ratio (standardized mean difference [SMD], 0.69; 95% confidence interval [CI], 0.35–1.02); blood S100B (SMD, 0.88; 95% CI, 0.59–1.17), matrix metalloproteinase-9 (MMP-9; SMD, 0.66; 95% CI, 0.46–0.86), and zonulin (SMD, 1.17; 95% CI, 0.04–2.30). Here, MMP9 is linked to psychotic disorder.