Our findings may also inform future genome-wide association (GWA) analyses that will help further elucidation of the complex genetic architecture of conduct behaviour and substance use. The overlapping genetic influences on CD symptoms and substance use (especially in males) indicate that genetic variants identified to play a role in conduct behaviour may also contribute to the genetic architecture of vulnerability to externalizing behaviour in general and the other way around. Multivariate GWA studies could distinguish between genetic variants that are trait-specific versus those that contribute to externalizing behaviour in general and this may deepen our understanding of the genetic aetiology of these phenotypes.
