often than was prescribed, or use not in the intended manner). Other measures include retrospective reports of childhood attention deficit/hyperactivity disorder (ADHDsx) using items from Wender’s Childhood Problem Behavior Checklist (Wender, 1971) and novelty seeking scores (NS) using the 18-item version from Cloninger’s Tridimensional Personality Questionnaire (Cloninger et al., 1994). Scores for ADHDsx and NS were rescaled such that their range is 0 to 1. Finally, we tested for association with a factor score based on the item loadings on one major factor for all disinhibitory phenotypes. We modeled this analysis off those previously conducted by investigators in Virginia (Dick et al., 2008; Hettema et al., 2008) and in the Netherlands (Boomsma et al., 2000). Because of non-normal distributions, we log transformed ADsx, ASPDsx, CDsx, and DDsx for the factor score analysis.
