ERIC Number: EJ696593
Record Type: Journal
Publication Date: 2004-Oct
Reference Count: N/A
Genetic and Environmental Contributions to Stability and Change of ADHD Symptoms between 8 and 13 Years of Age: A Longitudinal Twin Study
Larsson, Jan-Olov; Larsson, Henrik; Lichtenstein, Paul
Journal of the American Academy of Child and Adolescent Psychiatry, v43 n10 p1267 Oct 2004
Objective: To study the genetic and environmental contributions to stability and change of attention-deficit/hyperactivity disorder (ADHD) symptoms between 8 and 9 and 13 and 14 years of age. Method: The sample included 1,480 twin pairs born in Sweden between May 1985 and December 1986. At wave 1 in 1994, when twins were 8-9 years old, 1,106 (75%) of the parents responded to a mailed questionnaire, and at wave 2 when the twins were 13-14 years old, 1,063 (73%) responded. A checklist with 14 items based on the 14 DSM-III-R symptoms for ADHD was completed. Structural equation modeling was used to analyze the data. Results: A relatively high stability of ADHD symptoms over this 5-year period was found. This continuity was mainly due to the same genetic effects operating at both points in time. Change in symptoms between childhood and early adolescence was to a large extent due to new genetic effects in early adolescence but also due to new nonshared environmental effects that became important during adolescence. Conclusions: The genetic stability highlights the importance of the continuing search for genes and endophenotypes of ADHD.
Descriptors: Children, Environmental Influences, Foreign Countries, Early Adolescents, Psychiatry, Hyperactivity, Genetics, Attention Deficit Disorders, Twins, Symptoms (Individual Disorders)
Lippincott Williams & Wilkins, P.O. Box 1620, Hagerstown, MD 21741. Tel: 800-638-3030 (Toll Free); Fax: 301-223-2400.
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A
Identifiers - Location: Sweden