OBJECTIVE: This study investigated the role of maternal smoking during
pregnancy in the etiology of attention deficit hyperactivity disorder
(ADHD). METHOD: Subjects were 6-17-year-old boys with DSM-III-R ADHD (N =
140) and normal comparison subjects (N = 120) and their first-degree
biological relatives. Information on maternal smoking was obtained from
mothers in a standardized manner by raters who were blind to the proband's
clinical status. RESULTS: Twenty-two percent of the ADHD children had a
maternal history of smoking during pregnancy, compared with 8% of the
normal subjects. This positive association remained significant after
adjustment for socioeconomic status, parental IQ, and parental ADHD status.
Significant differences in IQ were found between those children whose
mothers smoked during pregnancy and those whose mothers did not smoke (mean
IQ = 104.9, SD = 12.3, and mean = 115.4, SD = 12.2, respectively).
CONCLUSIONS: These findings suggest that maternal smoking during pregnancy
is a risk factor for ADHD. If confirmed, these findings will stress the
importance of programs aimed at smoking prevention in nonsmoking women and
smoking cessation in smoking women of childbearing age.