45 Toxoplasma gondii an intracellular parasite, has also been considered to be a putative etiological agent acting both before and after birth to increase risk of psychosis.46 Other possible antenatal environmental risk factors In utero exposure to noninfectious environmental agents, such as check details maternal stress,47 maternal malnutrition,48 maternal diabetes,11 smoking,49 Inhibitors,research,lifescience,medical and rhesus incompatibility,50 has also been considered. A number of investigations have examined the relationship between experience of a stressful event during pregnancy or maternal

stress more generally, and later psychosis. Risk of schizophrenia is claimed to be increased among offspring of mothers who were exposed to sudden widespread disasters while pregnant, such as the German invasion of the Netherlands Inhibitors,research,lifescience,medical in 194051 and a flood in southwest Holland in 1953.52 Paternal death during pregnancy was examined as a proxy for maternal stress in a study by Huttunen and Niskanen53 in 1978. They found a sixfold increase in risk of schizophrenia among those whose fathers had died while they were in utero, compared with those subjects Inhibitors,research,lifescience,medical who lost their fathers in infancy. Negative results have also been published indicating that considerable caution must be exercised

in drawing conclusions about the role of maternal stress during pregnancy and risk of schizophrenia among offspring.54,55 Much evidence has accumulated to link early life nutritional status to adult health, particularly in the

area of cardiovascular research.56 It has been argued that the same may be true for schizophrenia.57 Increased maternal body mass Inhibitors,research,lifescience,medical index (BMI) or childhood BMI and antenatal exposure to famine have all been found to be associated with an increased risk of schizophrenia.58-61 Perhaps the best evidence linking nutrition to risk of schizophrenia comes from the Dutch Hunger Winter studies.62 Food intake for the Dutch population declined dramatically following a Nazi blockade in the mid-1940s. Members of the birth cohort exposed to this food deprivation during first trimester were found to have Inhibitors,research,lifescience,medical higher rates of hospitalized schizophrenia.63 In addition, subsequent investigation has demonstrated that first trimester exposure to famine in a subsample from unless the cohort was associated with structural brain abnormalities on magnetic resonance imaging (MRI).64 Less is understood, however, about the mechanisms underlying these nutritional associations and whether, for example, micronutrient intake is more important than overall caloric consumption. Vitamin D has recently been postulated as a relevant nutritional factor, with low levels of vitamin D being claimed to be linked to risk of psychosis.65 In a Finnish birth cohort, McGrath et al found that vitamin D supplementation during the first year of life was protective for adult schizophrenia in males.