Historical change and neurodevelopmental disorders

The first part of this presentation will discuss ongoing studies that link historical changes to the risk of neurodevelopmental disorders. Two examples will be used. One is a series of studies based on two epic famines, the Dutch Hunger Winter of 1944-45 and the Chinese famine of 1959-1961. These investigations have shown a relationship between early prenatal exposure to famine and risk of schizophrenia (in Holland and China) and other neurodevelopmental disorders (in Holland). The other is a series of studies based on the mass migration from low and middle income countries (often former colonies) to western Europe in the second half of the twentieth century. Some migrant groups (who are also ethnic minorities) have been shown to have a very high risk of psychotic disorders, and possibly other neurodevelopmental disorders. The second part will discuss how our improved understanding of these links is helping us to conceptualize and test biological pathways. Findings on prenatal famine suggest hypotheses about genetic mutations and epigenetic effects. Findings on migrants and ethnic minorities suggest hypotheses about childhood social experience. The third part will discuss implications for prevention. Although preventive interventions based on the results thus far would be premature, I will anticipate and address the complex questions about preventive interventions that may soon arise.