Abstract
AIMS: To examine the association between developmental trajectories of inattention, hyperactivity-impulsivity and delinquency through childhood and adolescence (ages 8-16 years) and subsequent binge drinking and marijuana use in early adulthood (age 21 years). DESIGN: Prospective naturalistic follow-up of children with attention deficit/hyperactivity disorder (ADHD) previously enrolled in a randomized controlled trial (RCT). Treatment-phase assessments occurred at 3, 9 and 14 months after randomization; follow-up assessments occurred at 24 months, 36 months, and 6, 8 and 12 years after randomization. SETTING: Secondary analysis of data from the Multimodal Treatment Study of ADHD (MTA), a multi-site RCT comparing the effects of careful medication management, intensive behavior therapy, their combination, and referral to usual community care. PARTICIPANTS: A total of 579 children with DSM-IV ADHD combined type, aged 7.0 and 9.9 years at baseline (mean = 8.5, SD = 0.80). MEASUREMENTS: Ratings of inattention, hyperactivity-impulsivity and delinquency were collected from multiple informants at baseline and through the 8-year follow-up. Self-reports of binge drinking and marijuana use were collected at the 12-year follow-up (mean age 21 years). FINDINGS: Trajectories of worsening inattention symptoms and delinquency (and less apparent improvement in hyperactivity-impulsivity) were associated with higher rates of early adult binge drinking and marijuana use, compared with trajectories of stable or improving symptoms and delinquency (of 24 comparisons, all P-values <0.05), even when symptom levels in stable trajectories were high. CONCLUSIONS: Worsening inattention symptoms and delinquency during adolescence are were associated with higher levels of early adult substance use; this pattern may reflect a developmental course of vulnerability to elevated substance use in early adulthood.