Does the prenatal environment contribute to subsequent mental health in childhood? --A question that has been around since antiquity, but still remains difficult to answer. Compelling evidence from epidemiological studies and animal experiments support the concept of developmental origins of health and disease whereby risk is conferred via early environmental influences rather than genetic transmission. However, it is difficult to disentangle the effect of confounding factors.

To critically explore biologically plausible mechanisms and potential postnatal moderators in child mental health using evidence from epidemiological studies. Examples are drawn from work on Attention Deficit Hyperactivity Disorder (ADHD) symptoms.

Data come from prospective pregnancy cohorts primarily gathered in Sweden as well as in other Northern European countries. The research is based on longitudinal design and emphasizes the critical role that development plays in the manifestation of behavior problems.

Longitudinal modeling reveals that both prenatal and postnatal environmental factors have an impact on child mental health problems.

Exposure to adverse environmental factors related to maternal lifestyle during prenatal development have a lasting impact on child development. Therefore, the time of pregnancy offers a critical window of opportunity for prevention.