Results of our multivariate genetic analyses raise a follow-up question regarding the role of the ADHD measure in the latent behavioral disinhibition construct, as well as its relationship with response inhibition: Is it truly the comorbidity between the different components of behavioral disinhibition that accounts for its association with response inhibition, or is it mainly the effect of attention problems, which might be predicted based on previous studies of the relationship between ADHD symptoms and executive functions? To address this question, we tested two additional models, which separately included composite scores of the two DSM-guided subscales of ADHD. Attention problem and hyperactivity/impulsivity composites were constructed by applying the same method used in the full ADHD composite (i.e., summed z scores of self-, parent, and teacher reports).
