It has been suggested that infections during early life can play a role in the development of schizophrenia. Most studies have looked at the effects of maternal infections on the developing fetus and of the few that have looked at the effects of childhood infections the results have been inconclusive. A study of 1.2 million children born in Sweden between 1973 and 1985 found that 2,435 of them had been admitted to hospital with bacterial infections of the central nervous system while 6,550 had been admitted with viral infections. 2,269 of the children had been admitted to hospital for treatment with non-affective psychotic illnesses. The researchers found a slightly increased risk of psychosis and schizophrenia among the children who had suffered from viral infections. Exposure to mumps or cytomegalovirus were associated with subsequent psychoses. There was no evidence of increased risk in relation to bacterial infections.
Dalman, Christine ... [et al] - Infections in the CNS during childhood and the risk of subsequent psychotic illness: a cohort study of more than one million Swedish subjects American Journal of Psychiatry January 2008, 165(1), 59-65