To Örebro University

Disruptive behavior disorders (e.g., attention-deficit/hyperactivity disorder [ADHD], oppositional defiant disorder [ODD], conduct disorder [CD]) affect 5–10 % of youth and represent the primary reason for youth referrals to clinicians (APA, 2013). DSM-V includes callous-unemotional (CU) traits (specifier ‘with prosocial emotions’) to CD (APA, 2013; Frick et al., 2014). Research suggests an association between CU traits and ADHD symptoms (Graziano et al., 2016; Babinski, et al., 2017; Haas et al., 2018). The genetic and environmental overlap between CU traits and ADHD symptoms were examined in a sample of 1,189 five year-old children using teacher-ratings, the PrEschool Twin Study in Sweden (PETSS). The correlations between CU traits and hyperactivity/impulsivity, and between CU traits and inattention were rp = .53, p<.05 and .44, p<.05, respectively. For CU traits, genetic factors accounted for 25%, p<.05 of the variance, the shared environment accounted for 48%, p<.05, and the non-shared environment for 27%, p<.05. For hyperactivity/impulsivity, genetic factors accounted for 85%, p<.05 of the variance and the non-shared environment accounted for 15%, p<.05. For inattention, genetic factors accounted for 43%, p<.05 of the variance, the shared environment accounted for 38%, p<.05, and the non-shared environment for 19%, p<.05. For CU traits and hyperactivity/impulsivity, rg = .58 (.36, .88), rc = .84 (.46, 1.00), re = .24 (.10, .37). For CU traits and inattention, rg = .33 (.00, .61), rc = .63 (.43, .82), re = .30 (.17, .43). These findings indicate that CU traits and ADHD symptoms partly share a common genetic and environmental etiology.