Do personality traits explain the association between childhood attention-deficit hyperactivity disorder symptoms and substance use and problems in young adults?

Childhood attention-deficit/hyperactivity disorder (ADHD) is associated with increased risk of substance-related problems in adulthood. While comorbid disorders have been hypothesized to account for this risk, the role of personality factors has not yet been examined, despite findings of robust associations between temperament and personality traits and both ADHD and substance use problems. 349 young adults ages 18–38 years ( M = 23.22 years, SD = 4.79, 54.7% male) completed a multi-informant assessment protocol, including self and informant retrospective measures of childhood ADHD symptoms, self-report measures of personality traits (NEO-FFM), and ratings of substance use and related problems. A multiple mediational framework was used to examine whether personality traits explained the association between childhood ADHD symptoms and substance use and problems in adulthood. Results revealed that childhood hyperactivity–impulsivity, but not inattention, directly influenced substance use and problems in adulthood. However, several indirect effects involving personality traits also emerged. Neuroticism and agreeableness appeared to be more relevant for explaining links between childhood ADHD symptom dimensions and substance-related problems, whereas conscientiousness and openness appeared to explain associations between childhood ADHD symptom dimensions and substance use. Overall, findings highlight the importance of personality traits for understanding the overlap among disorders on the externalizing spectrum. [ABSTRACT FROM AUTHOR]