Journal of Abnormal Child Psychology

, Volume 33, Issue 2, pp 219–229

Understanding the Covariation Among Childhood Externalizing Symptoms: Genetic and Environmental Influences on Conduct Disorder, Attention Deficit Hyperactivity Disorder, and Oppositional Defiant Disorder Symptoms


  • Danielle M. Dick
    • Department of PsychiatryWashington University in St. Louis
  • Richard J. Viken
    • Department of PsychologyIndiana University
  • Jaakko Kaprio
    • University of Helsinki & National Public Health Institute
  • Lea Pulkkinen
    • University of Jyväaskylä
    • Department of PsychologyIndiana University
    • Department of PsychologyIndiana University

DOI: 10.1007/s10802-005-1829-8

Cite this article as:
Dick, D.M., Viken, R.J., Kaprio, J. et al. J Abnorm Child Psychol (2005) 33: 219. doi:10.1007/s10802-005-1829-8


Conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) are common childhood externalizing disorders that frequently co-occur. However, the causes of their comorbidity are not well understood. To address that question, we analyzed data from > 600 Finnish twin pairs, who completed standardized interviews at age 14. Behavior genetic methods were used to examine how genetic/environmental factors contribute to each disorder’s symptoms and to their covariation. We found significant genetic effects on each disorder with only modest evidence of shared environmental influences. Our data suggest the comorbidity among CD, ADHD, and ODD is primarily explained by shared genetic influences; however, each disorder was also under unique genetic influence, supporting the distinction of each disorder.


attention deficit hyperactivity disorderconduct disorderoppositional defiant disordergeneticsexternalizing disorders

Copyright information

© Springer Science + Business Media, Inc. 2005