There have been many genetically informed studies of conduct disorder and related/component behaviors such as aggression, externalizing behavior, psychopathy, and callous-unemotional traits. Accordingly, our review is selective rather than exhaustive. To the extent possible, we focus on genetically informed studies that are consistent with the Diagnostic and Statistical Manual Revised Third Version and Fourth Version (DSM-III-R and DSM-IV) (American Psychiatric Association, 1987, 1994) definition of conduct disorder as “a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate societal norms or rules are violated.” Conduct disorder diagnoses are typically given to individuals under 18 years of age; accordingly, we focus on studies of conduct disorder in individuals < 18 years. We note, however, that research on the molecular genetics of conduct disorder is still in its infancy, and there are very few studies of conduct disorder according to the strict DSM criteria. Thus, in our review of gene identification efforts for conduct disorder we opted to include larger scale meta-analytic findings of phenotypes closely related to conduct disorder, including aggression and antisocial behavior.
