, Volume 37, Issue 2, pp 153-167
Date: 18 Nov 2008

A Common Genetic Factor Explains the Covariation Among ADHD ODD and CD Symptoms in 9–10 Year Old Boys and Girls

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Previous studies examining the covariation among Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) have yielded inconsistent results. Some studies have concluded that the covariation among these symptoms is due to common genetic influences, whereas others have found a common environmental overlap. The present study investigated the genetic and environmental correlations among these three childhood disorders, based on a sample of 1,219 twins, age 9–10 years. A latent externalizing behavior factor was found to explain the covariance among ADHD, ODD and CD symptoms. Genetic influences explained more than half of the variance in this externalizing factor in both boys and girls. There were also unique genetic and environmental influences in each set of symptoms, suggesting some etiological independence of the three disorders. Our findings have implications for molecular genetic studies trying to identify susceptibility genes for these disorders.

This study was funded by NIMH (R01 MH58354). Catherine Tuvblad was supported by post-doctoral stipends from the Swedish Council for Working Life and Social Research (Project 2006-1501) and the Sweden-America Foundation. Adrian Raine was supported by NIMH (Independent Scientist Award K02 MH01114-08). We thank the Southern California Twin Project staff for their assistance in collecting data, and the twins and their families for their participation.