Maternal smoking during pregnancy and attention deficit hyperactivity disorder symptoms in offspring.
OBJECTIVE
The aim of this study was to examine whether smoking during pregnancy is associated with symptoms of attention deficit hyperactivity disorder (ADHD) in offspring and whether these effects are additional to genetic influences.


METHODS
Children's ADHD symptoms (parent- and teacher-rated), maternal smoking during pregnancy, conduct disorder symptoms, and family adversity were assessed with questionnaires for a population-based sample of twins (1,452 twin pairs 5-16 years of age).


RESULTS
Although genetic influences accounted for most of the variance in offspring ADHD, maternal smoking during pregnancy was still found to show a significant environmentally mediated association. Maternal smoking remained a significant influence when other potential confounds were taken into account.


CONCLUSIONS
Maternal smoking during pregnancy appears to show an association with offspring ADHD symptoms that is additional to the effects of genes and not attributable to shared rater effects, clinical referral biases, or covariation with antisocial behavior.
Department os Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, Wales, UK.
Anita
A
Thapar
Tom
T
Fowler
Frances
F
Rice
Jane
J
Scourfield
Marianne
M
van den Bree
Hollie
H
Thomas
Gordon
G
Harold
Dale
D
Hay
D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D002648:Child; D016241:Child of Impaired Parents / Q000706:statistics & numerical data; D002675:Child, Preschool; D015986:Confounding Factors, Epidemiologic; D004200:Diseases in Twins / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D008957:Models, Genetic; D009538:Nicotine / Q000009:adverse effects; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011297:Prenatal Exposure Delayed Effects; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D011795:Surveys and Questionnaires
D009538:Nicotine