Objective: Adolescents and adults with attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUD) are increasingly recognized in clinical practice. The role of pharmacological treatment for ADHD in these comorbid individuals remains unclear.
Methods: A systematic review of the medical literature was conducted through PubMed, supplemented with data from scientific presentations, to evaluate the role of medication treatment of ADHD in substance abusing individuals with ADHD. Meta-analysis was used to evaluate the effects of medication therapy on ADHD and SUD outcomes in general, while specifically addressing trial design, trial duration, retention, class of medication, age group, concurrent psychotherapy, and outcome in both SUD and ADHD domains.
Results: Four studies in adolescents and five studies in adults with ADHD plus SUD were identified (two controlled and seven open studies; n = 222 subjects). The standard mean difference (SMD) indicated statistically significant improvements in ADHD and SUD that were not maintained when evaluating controlled studies only. Albeit limited by power, trial duration, retention rate, and age group did not influence outcome. No worsening of SUD or drug-drug interactions were observed in any of the studies. The results could not be accounted for by any single study or by publication bias.
Conclusion: Treating ADHD pharmacologically in individuals with ADHD plus SUD has a moderate impact on ADHD and SUD that is not observed in controlled trials and does not result in worsening of SUD or adverse interactions specific to SUD. Further controlled trials evaluating the effect of novel combinations of psychotherapy and ADHD pharmacotherapy on SUD relapse in these groups are warranted.