Revisiting the association between maternal smoking during pregnancy and ADHD

Objective

Studies examining the relationship between maternal smoking during pregnancy and the development of Attention Deficit Hyperactivity Disorder (ADHD) among offspring have yielded mixed results, with some studies suggesting a strong association and others finding no association. These studies have varied in quality of design and measures. The purpose of this study was to evaluate the association between maternal smoking during pregnancy and offspring ADHD, using detailed prospective smoking data and subsequent follow-up data from the Collaborative Perinatal Project (CPP).

Method

Maternal smoking status was collected throughout pregnancy during the original CPP study. Offspring were followed-up in early adulthood and questioned about ADHD symptoms and diagnosis. Logistic regression was used to model the association between maternal smoking during pregnancy and ADHD. Linear and logistic regression were used to examine clinical characteristics and remission rates associated with ADHD in relation to maternal smoking.

Results

No association was found between maternal smoking during pregnancy and offspring ADHD. Further, no differences in age of onset, number of symptoms, or likelihood of remission were found among ADHD subjects with and without a history of maternal smoking during pregnancy.

Conclusions

These findings do not support the hypothesis that maternal smoking during pregnancy is causally related to ADHD. Ongoing research should continue to strive to identify those environmental or genetic factors that may enhance the impact of maternal smoking on ADHD or that may be associated more clearly with the development and potential prevention of ADHD.