Symptom covariance accounts for behavioral approach associations across impulse control disorders.

Behavioral approach system (BAS) dysfunction has been identified as a correlate of and a potential mechanism for attention-deficit/hyperactivity disorder (ADHD) and comorbid disorders. This study examined the role of symptom covariation in the relations among BAS dysfunction, ADHD symptoms, and comorbid impulsive personality disorder features. Undergraduates (N = 207) completed measures of BAS functioning, ADHD symptoms, and borderline and antisocial personality disorder symptoms, and associated features (i.e., relational aggression). Hierarchical regression suggested that age, impulsive ADHD symptoms, and relational aggression were associated with BAS functioning. Adding other ADHD symptom dimensions (inattention, hyperactivity) and antisocial and borderline scores to the model did not increase variance accounted for beyond that accounted for by ADHD impulsivity scores. Results highlight a role of symptom covariance in the previously demonstrated relation between BAS, impulsive presentations of ADHD, and comorbid impulsive personality pathology. Implications for etiological models of ADHD and its co-occurrence with other disorders are discussed.