Relationship between antisocial behaviour, attention-deficit hyperactivity disorder and maternal prenatal smoking.

BACKGROUND There is substantial evidence that maternal smoking during pregnancy is associated with both antisocial behaviour and symptoms of attention-deficit hyperactivity disorder (ADHD) in offspring. However, it is not clear whether maternal smoking during pregnancy is independently associated with antisocial behaviour or whether the association arises because antisocial behaviour and ADHD covary. AIMS To examine the relationship between maternal smoking during pregnancy, antisocial behaviour and ADHD in offspring. METHOD Questionnaires concerning behaviour and environmental factors were sent to twins from the CaStANET study and data analysed using a number of bivariate structural equation models. RESULTS Maternal prenatal smoking contributed small but significant amounts to the variance of ADHD and of antisocial behaviour. The best fitting bivariate model was one in which maternal prenatal smoking had a specific influence on each phenotype, independent of the effect on the other phenotype. CONCLUSIONS Both antisocial behaviour and ADHD symptoms in offspring are independently influenced by maternal prenatal smoking during pregnancy.