Does Stimulant Therapy of Attention-Deficit/Hyperactivity Disorder Beget Later Substance Abuse? A Meta-analytic Review of the Literature

Abstract

Objective.Concerns exist that stimulant therapy of youths with attention-deficit/hyperactivity disorder (ADHD) may result in an increased risk for subsequent substance use disorders (SUD). We investigated all long-term studies in which pharmacologically treated and untreated youths with ADHD were examined for later SUD outcomes. Methods.A search of all available prospective and retrospective studies of children, adolescents, and adults with ADHD that had information relating childhood exposure to stimulant therapy and later SUD outcome in adolescence or adulthood was conducted through PubMed supplemented with data from scientific presentations. Meta-analysis was used to evaluate the relationship between stimulant therapy and subsequent SUD in youths with ADHD in general while addressing specifically differential effects on alcohol use disorders or drug use disorders and the potential effects of covariates. Results.Six studies—2 with follow-up in adolescence and 4 in young adulthood—were included and comprised 674 medicated subjects and 360 unmedicated subjects who were followed at least 4 years. The pooled estimate of the odds ratio indicated a 1.9-fold reduction in risk for SUD in youths who were treated with stimulants compared with youths who did not receive pharmacotherapy for ADHD (z = 2.1; 95% confidence interval for odds ratio [OR]: 1.1–3.6). We found similar reductions in risk for later drug and alcohol use disorders (z = 1.1). Studies that reported follow-up into adolescence showed a greater protective effect on the development of SUD (OR: 5.8) than studies that followed subjects into adulthood (OR: 1.4). Additional analyses showed that the results could not be accounted for by any single study or by publication bias. Conclusion.Our results suggest that stimulant therapy in childhood is associated with a reduction in the risk for subsequent drug and alcohol use disorders.

Impulsive choice and environmental enrichment: Effects of d-amphetamine and methylphenidate

“…In humans, the use of psychostimulant treatment for ADHD may protect against the development of substance use disorders [12,49,52,91], especially if treatment is started in childhood [for a review, see 43]. Conversely, the present results may also suggest that use of psychostimulants by individuals without ADHD could increase the risk of substance abuse problems.…”

European clinical guidelines for hyperkinetic disorder ? first upgrade

“…The available clinical data suggest that, whether or not sensitisation occurs, the net effect of treating children and young people with AD/HD with stimulant medication is to protect against, rather than lead to, later substance misuse. A meta-analysis of the available literature reported that those treated with stimulants were protected against the development of substance misuse problems by a factor of almost two (Odds Ratio, 1.9), compared with those whose AD/HD was not treated with stimulant medication [184]. Possible mechanisms for this protective effect include a reduction in AD/HD symptoms especially impulsive behaviour, a reduction in conduct disorder and later anti-social personality disorder, im-proved academic performance and career, or improved peer and family relationships.…”

Developments and challenges in the diagnosis and treatment of ADHD

“…This was consistent with an earlier meta-analysis. 83 However, a 36-month follow-up of the MTA study 84 and a 10-year follow-up study of a clinical sample 85 found no association between ADHD treatment and rates of substance use. Additional studies assessing large samples and following up participants into adolescence and/or adulthood are necessary to determine whether treatment has a protective effect on substance use rates and development of dependence.…”