TY - JOUR

T1 - Infections of the central nervous system as a risk factor for mental disorders and cognitive impairment

T2 - A nationwide register-based study

AU - Pedersen, Emilie M.J.

AU - Köhler-Forsberg, Ole

AU - Nordentoft, Merete

AU - Christensen, Rune H.B.

AU - Mortensen, Preben B.

AU - Petersen, Liselotte

AU - Benros, Michael E.

PY - 2020

Y1 - 2020

N2 - Background: 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. Methods: 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. Results: 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 < 0.001) than bacterial (HR 1.24, 95% CI 1.15–1.35). Encephalitis (HR 1.64, 95% CI 1.41–1.90) conferred a higher risk (p < 0.001) than meningitis (HR 1.26, 95% CI 1.18–1.35). The risk was highest for organic mental disorders (HR 6.50, 95% CI 5.11–8.28) and disorders of intellectual development (HR 3.56, 95% CI 2.94–4.31), with a HR of 19.19 (95% CI 7.46–49.35) for profound disorder of intellectual development (IQ < 20). Furthermore, CNS infection decreased the RR of completing 9th grade of mandatory schooling (RR 0.89, 95% CI 0.88–0.91) and lowered average grade score for completers (p < 0.001). Conclusions: CNS infections increased the risk for mental disorders and decreased the likelihood of completing 9th grade, indicating long-term consequences of CNS infections.

AB - Background: 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. Methods: 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. Results: 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 < 0.001) than bacterial (HR 1.24, 95% CI 1.15–1.35). Encephalitis (HR 1.64, 95% CI 1.41–1.90) conferred a higher risk (p < 0.001) than meningitis (HR 1.26, 95% CI 1.18–1.35). The risk was highest for organic mental disorders (HR 6.50, 95% CI 5.11–8.28) and disorders of intellectual development (HR 3.56, 95% CI 2.94–4.31), with a HR of 19.19 (95% CI 7.46–49.35) for profound disorder of intellectual development (IQ < 20). Furthermore, CNS infection decreased the RR of completing 9th grade of mandatory schooling (RR 0.89, 95% CI 0.88–0.91) and lowered average grade score for completers (p < 0.001). Conclusions: CNS infections increased the risk for mental disorders and decreased the likelihood of completing 9th grade, indicating long-term consequences of CNS infections.

KW - CNS infection

KW - Cognition

KW - Mental disorders

KW - Nationwide and Epidemiology

KW - Register-based

U2 - 10.1016/j.bbi.2020.04.072

DO - 10.1016/j.bbi.2020.04.072

M3 - Journal article

C2 - 32353515

AN - SCOPUS:85084965717

VL - 88

SP - 668

EP - 674

JO - Brain, Behavior, and Immunity

JF - Brain, Behavior, and Immunity

SN - 0889-1591

ER -