Sex Differences in Effectiveness of Extended-Release Stimulant Medication among Adolescents with Attention-Deficit/Hyperactivity Disorder

This study examined whether adolescent females with attention-deficit/hyperactivity disorder (ADHD) are differentially responsive than their male counterparts to extended-release stimulant medications. This investigation may bear special importance for an adolescent (as opposed to child) population, because hormonal and metabolism differences between sexes are most likely to emerge at this time. Male (n = 19) and female (n = 16) adolescents, ages 16-19 with ADHD, participated in a randomized, double-blind crossover study evaluating the effectiveness of osmotic-release methylphenidate, extended release amphetamine salts, placebo, and routine limited medication regimen. Medication efficacy was evaluated using ADHD symptom ratings from adolescent self-report and parent report, along with objective measures of inattention and hyperactivity/impulsivity during driving performance and neuropsychological tasks. Males and females were largely equivalent in impairment, and medication was similarly effective in reducing symptoms. No interactions were found between sex and medication on any measure of effectiveness or side effects. This finding suggests that the efficacy and tolerability of extended-release stimulant medications is equivalent for male and female adolescents with ADHD.