Infections of the central nervous system as a risk factor for mental disorders and cognitive impairment: A nationwide register-based study

• Published in: Brain, behavior, and immunity behavior, and immunity, 2020-08, Vol.88, p.668-674
• Main Authors: Pedersen, Emilie M.J., Köhler-Forsberg, Ole, Nordentoft, Merete, Christensen, Rune H.B., Mortensen, Preben B., Petersen, Liselotte, Benros, Michael E.
• Format: Article
• Language: English
• Subjects: Central Nervous System; CNS infection; Cognition; Cognitive Dysfunction - epidemiology; Cohort Studies; Humans; Mental disorders; Mental Disorders - epidemiology; Nationwide and Epidemiology; Proportional Hazards Models; Register-based; Risk Factors
• ISSN: 0889-1591; 1090-2139
• DOI: 10.1016/j.bbi.2020.04.072

•CNS infections are associated with an increased risk of mental disorders.•Viral CNS infections conferred a higher risk than bacterial CNS infections.•Risk of mental disorders increased with the temporal proximity to the CNS infection.•Children exposed to CNS infections were less likely to complete mandatory schooling. CNS infections have been suggested as risk factors for cognitive decline and mental disorders; however, large-scale studies have been lacking regarding types and agents of CNS infections. We utilized the unique personal registration number to create a cohort of 1,709,867 individuals born 1977–2010. CNS infection was exposure and data were analysed with 1) cox regression analyses estimating hazard ratios (HR) for developing mental disorders and 2) binomial regression estimating relative risk (RR) for completion of 9th grade including average grade score in a sub-cohort born 1988–1998. CNS infection increased the risk for developing mental disorders with a HR of 1.34 (95% CI 1.27–1.42). The highest risk observed was within the first 6 months after the CNS infection with a HR of 26.98 (95% CI 21.19–34.35). Viral CNS infections (HR 1.47, 95% CI 1.35–1.61) conferred a higher risk (p