Association between central nervous system infections during childhood and adult onset schizophrenia and other psychoses: a 28-year follow-up.

BACKGROUND Maternal exposure to influenza epidemics during pregnancy may increase the risk of schizophrenia in the offspring. We investigated the association between central nervous system (CNS) infections defined prospectively up to the age of 14, and later onset of schizophrenia and other psychoses in the 1966 birth cohort in Northern Finland, which covers 96% of all births in the area during that year. METHODS Data regarding CNS infections were collected 1966-1980. Registered diagnoses of psychoses in 1982-1993 were validated on DSM-III-R criteria. RESULTS Out of 11,017 subjects, 145 had suffered a CNS infection during childhood, 102 of them a viral infection, 76 had DSM-III-R schizophrenia and 53 some other psychosis. Four cases of schizophrenia had suffered viral CNS infection and two cases of other psychosis bacterial infection. When neurological abnormalities and father's social class were adjusted odds ratio (OR) of schizophrenia after viral CNS infection was 4.8 (95% confidence intervals [CI] : 1.6-14.0); the other significant risk factors being intelligence quotient (IQ) < 85, perinatal brain damage and male sex but not epilepsy. Similarly adjusted OR of other psychoses was 6.9 (95% CI: 1.4-32.8) after bacterial CNS infection; the other significant risk factors being IQ < 85 and severe hearing defect. Two of the live viral infections were caused by Coxsackie B5 during an epidemic in which 16 neonates were infected together. CONCLUSIONS Central nervous system infections during childhood clearly carried an increased risk of adult onset schizophrenia or other psychoses, viral infections being important for schizophrenia, particularly Coxsackie B5 during the newborn period.