Figure 1.
Genetic factor structure of Cholesky decomposition. The model is constructed such that A1 represents a genetic factor that can load onto all five observed variables, A2 loads onto all three ADHD phenotypic factors (inattention [INATT], forgetfulness [FORGET], and hyperactivity/impulsivity [HYPER]) as well as alcohol dependence (AD), etc. Path a54 represents genetic covariance specific to the HYPER factor and AD. A model that is identical except for the juxtaposition of HYPER and FORGET was used to assess genetic covariance specific to FORGET and AD; likewise for INATT. CD = conduct disorder.