Oxytocin levels in individuals with schizophrenia are high in cerebrospinal fluid but low in serum: A systematic review and meta-analysis

• Published in: Metabolic brain disease Vol. 36; no. 8; pp. 2415 - 2424
• Main Authors: Hernández-Díaz Yazmín, González-Castro, Thelma Beatriz, Alfonso, Tovilla-Zárate Carlos, López-Narváez, María Lilia, Genis-Mendoza, Alma Delia, Castillo-Avila, Rosa Giannina, Ramos-Méndez, Miguel Ángel, Juárez-Rojop, Isela Esther
• Format: Journal Article
• Language: English
• Published: New York Springer Nature B.V 01.12.2021
• Subjects: Biomarkers; Cerebrospinal fluid; Confidence intervals; Evaluation; Mental disorders; Meta-analysis; Oxytocin; Reviews; Schizophrenia; Systematic review
• ISSN: 0885-7490; 1573-7365
• DOI: 10.1007/s11011-021-00836-y

Schizophrenia is a debilitating mental illness. Levels of oxytocin have been proposed as a biomarker of schizophrenia; however, the observed levels of oxytocin in individuals with schizophrenia have been inconsistent across studies. We performed a meta-analysis to evaluate oxytocin levels in plasma, serum and cerebrospinal fluid to see if there are statistically different concentrations between individuals with schizophrenia and the comparison group. The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Following the inclusion and exclusion criteria, 14 studies were included in the meta-analysis. The quality of the study was evaluated by the Newcastle–Ottawa Scale (NOS). A random-effects model was performed using the Comprehensive Meta-analysis software with the standardized mean difference (SMD) and 95% confidence intervals (CIs). Serum oxytocin levels in individuals with schizophrenia were significantly lower than that in comparison group (SMD =  − 1.74, 95% CI =  − 3.22 to − 0.26, p = 0.02) but cerebrospinal fluid oxytocin levels in individuals with schizophrenia were significantly higher than those in the comparison group (SMD = 0.55, 95% CI = 0.05 to 1.04, p = 0.03). Our results suggest that oxytocin levels in cerebrospinal fluid are increased in individuals with schizophrenia but decreased in serum. Therefore, the oxytocin system dysregulation may play a role in the pathophysiology of schizophrenia and it should be measured in more populations for a possible implementation as a biomarker of schizophrenia.