Birth weight and attention-deficit/hyperactivity symptoms in childhood and early adolescence: A prospective Swedish twin study
2007 (English)In: Journal of the American Academy of Child and Adolescent Psychiatry, ISSN 0890-8567, E-ISSN 1527-5418, Vol. 46, no 3, 370-377 p.Article in journal (Refereed) Published
OBJECTIVE: To determine whether low birth weight increases the risk of attention-deficit/hyperactivity disorder (ADHD) in childhood and early adolescence. METHOD: In a population-based sample of 1,480 twin pairs born in the period 1985-1986 ascertained from the Swedish Twin Registry, birth weight was collected prospectively through the Medical Birth Registry. ADHD symptoms were measured with a 14-item checklist covering DSM-III-R criteria (parental rating) at age 8 to 9 years and 13 to 14 years. We used both a dichotomous approach for birth weight (>400 g or 15% weight difference) and ADHD (eight or more symptoms) and continuous measures to investigate between- and within-twin pair effects. RESULTS: Our results showed that low birth weight was a risk factor for symptoms of ADHD and the associations did not diminish when we controlled for genetic influence. The lighter twin in birth weight-discordant pairs had on average 13% higher ADHD symptom score at age 8 to 9 years (p = .006) and 12% higher ADHD score at age 13 to 14 years (p = .018) compared with the heavier twin. The genetic correlations suggest modest or no genetic overlap between birth weight and ADHD. CONCLUSIONS: The hypothesis that low birth weight is associated with the development of ADHD symptoms was supported in this prospective twin study. Fetal growth restriction seems to represent a modest but fairly consistent environmental influence on the development of ADHD symptoms.
Place, publisher, year, edition, pages
2007. Vol. 46, no 3, 370-377 p.
attention-deficit/hyperactivity disorder, birth weight, twins
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-10623DOI: 10.1097/01.chi.0000246059.62706.22ISI: 000244428800012PubMedID: 17314723OAI: oai:DiVA.org:uu-10623DiVA: diva2:38391