6. Does Treatment with Stimulant Medication Increase Risk for Substance Use disorder: Longitudinal Study of an Important and Complicated Question

Possible relations between stimulant treatment of ADHD and risk for subsequent substance use (SU) remain debated and clinically relevant. The prospective, longitudinal assessments into early adulthood of children in the Multimodal Treatment Study of Children with ADHD (MTA) provided a unique opportunity to test this association while considering methodologic complexities. Initiated as a 14-month randomized clinical trial of medication and behavior therapy for ADHD, the MTA transitioned to a longitudinal observational study. Assessments included demographic, clinical, and treatment variables. This multi-site study (US and CA) included 579 children with rigorously diagnosed DSM-IV combined-type ADHD. Participants were repeatedly assessed to mean age 25. Stimulant treatment was measured prospectively for 16 years using parent followed by young adult report. Frequency of heavy drinking, marijuana use, daily cigarette smoking, and illicit drug use were self-reported. Generalized multilevel linear models showed no evidence that current or prior stimulant treatment or their interaction were associated with SU after adjusting for developmental trends in SU and age. Marginal structural models adjusting for dynamic confounding by demographic, clinical, and familial factors revealed no evidence that more years of stimulant treatment or continuous, uninterrupted stimulant treatment predicts adulthood SU or substance use disorder (SUD). Thus, we found no evidence that stimulant treatment increased or decreased risk for later frequent SU or SUD. These findings do not appear to result from other factors driving treatment decisions over time, and findings held even after considering opposing age-related trends in stimulant treatment and substance use. Support provided by NIDA and NIMH.Abstract Possible relations between stimulant treatment of ADHD and risk for subsequent substance use (SU) remain debated and clinically relevant. The prospective, longitudinal assessments into early adulthood of children in the Multimodal Treatment Study of Children with ADHD (MTA) provided a unique opportunity to test this association while considering methodologic complexities. Initiated as a 14-month randomized clinical trial of medication and behavior therapy for ADHD, the MTA transitioned to a longitudinal observational study. Assessments included demographic, clinical, and treatment variables. This multi-site study (US and CA) included 579 children with rigorously diagnosed DSM-IV combined-type ADHD. Participants were repeatedly assessed to mean age 25. Stimulant treatment was measured prospectively for 16 years using parent followed by young adult report. Frequency of heavy drinking, marijuana use, daily cigarette smoking, and illicit drug use were self-reported. Generalized multilevel linear models showed no evidence that current or prior stimulant treatment or their interaction were associated with SU after adjusting for developmental trends in SU and age. Marginal structural models adjusting for dynamic confounding by demographic, clinical, and familial factors revealed no evidence that more years of stimulant treatment or continuous, uninterrupted stimulant treatment predicts adulthood SU or substance use disorder (SUD). Thus, we found no evidence that stimulant treatment increased or decreased risk for later frequent SU or SUD. These findings do not appear to result from other factors driving treatment decisions over time, and findings held even after considering opposing age-related trends in stimulant treatment and substance use. Support provided by NIDA and NIMH.

By the end of this session, participants will be able to:

1. Describe different ways that the association between stimulant medication treatment for ADHD has been studied in relation to human substance use and substance use disorder.
2. Recognize that the research literature on ADHD stimulant treatment and substance use/substance use disorder, as a whole, does not currently provide support for stimulants increasing risk of human substance use/substance use disorder.
3. Assess existing studies on the association between stimulant treatment and substance use disorder.

CADDRA – Canadian ADHD Resource Alliance has been approved by the College of Family Physicians, the Royal College of Physicians and Surgeons of Canada and the Canadian Psychological Association to offer 1.25 continuing education credits for this session.  CADDRA maintains responsibility for the program.

Participation in a discussion forum is required to claim full credits.