Cocaine or Methamphetamine Use During Young Adulthood Following Stimulant Use for Attention-Deficit/Hyperactivity Disorder During Adolescence

IMPORTANCE: The prescribing of stimulant medications for attention-deficit/hyperactivity disorder (ADHD) has increased in the US. Prescription stimulants are one of the most commonly misused controlled substances during adolescence. Despite a 10-fold increase in stimulant-related overdose deaths in the past decade, the transitions from prescription stimulants to illicit stimulants (eg, cocaine, methamphetamine) remain relatively unknown in longitudinal population-based studies. OBJECTIVE: To determine the longitudinal transitions from adolescents’ prescription stimulant exposure (ie, stimulant therapy for ADHD and prescription stimulant misuse [PSM]) to later cocaine and methamphetamine use during young adulthood. DESIGN, SETTING, AND PARTICIPANTS: National longitudinal multicohort panels of US 12th grade public and private school students in the coterminous US were assessed annually (baseline cohort years 2005-2017 [between March and June]) and followed up across 3 waves over a 6-year period to 23 to 24 years of age (follow-up years 2011-2021 [between April and October]). EXPOSURE: History of self-reported stimulant therapy for ADHD at baseline. MAIN OUTCOMES AND MEASURES: Incidence and prevalence of past-year use of cocaine and methamphetamine during young adulthood (19-24 years of age). RESULTS: Among 5034 students enrolled at baseline (2589 [52.0%] female), 470 (10.2% [95% CI, 9.4%-11.2%]) reported use of stimulant therapy for ADHD, 671 (14.6% [95% CI, 13.5%-15.6%]) reported PSM only, and 3459 (75.2% [95% CI, 73.9%-76.4%]) reported neither (and served as population controls). In controlled analyses, there were no statistically significant differences between adolescents who reported stimulant therapy for ADHD at baseline compared with population controls in the adjusted odds of transitioning to later cocaine or methamphetamine initiation or use during young adulthood (19-24 years of age). In contrast, PSM during adolescence in those not treated with stimulants for ADHD had significantly higher odds of transitioning to later cocaine or methamphetamine initiation and use during young adulthood compared with population controls (adjusted odds ratio, 2.64 [95% CI, 1.54-4.55]). CONCLUSIONS AND RELEVANCE: In this multicohort study, adolescents’ stimulant therapy for ADHD was not associated with increased risk of later cocaine and methamphetamine use during young adulthood. Adolescents’ prescription stimulant misuse offered a signal for subsequent cocaine or methamphetamine use and warrants monitoring and screening.