A nine-week comparison favored lisdexamfetamine over atomoxetine on total parent-rated functional impairment and two of six domains. The findings were secondary outcomes with uncorrected p values, and do not establish superiority across every aspect of everyday functioning.
Nagy and colleagues reported functional outcomes from a randomized, double-blind, dose-optimized trial involving 267 children and adolescents aged 6–17 years. Investigators judged their previous methylphenidate response inadequate. Participants received lisdexamfetamine or atomoxetine; there was no placebo arm.
Parents or guardians completed the Weiss Functional Impairment Rating Scale–Parent Report at baseline and at week nine or early termination. The scale concerns functioning in areas such as family life, school, social activities and life skills. It is different from a laboratory attention test or a direct measure of academic achievement.
Both treatment groups improved from baseline across the scale’s domains. Between-treatment comparisons nominally favored lisdexamfetamine for Learning and School, Social Activities and the total score. Reported effect sizes were 0.43, 0.34 and 0.27, respectively. The other four domain comparisons did not demonstrate significant treatment differences.
The total-score comparison had a nominal p value of 0.046. Because these secondary analyses were not corrected for multiple comparisons, that result should remain qualified. A statistical difference also does not automatically identify the minimum improvement that families would consider important when comparing two active medicines.
The authors noted that nine weeks might underestimate atomoxetine’s eventual effects, and functional change can take longer than symptom relief. Two hundred participants completed the study; endpoint analyses also incorporated valid assessments from earlier termination. Prior medication experience could influence expectations despite blinding.
The trial was industry funded. Its selected population limits extension to treatment-naïve children, adults or people using stimulants without medical supervision. Parent-rated functioning does not supply a drug concentration or a driving-impairment threshold. The evidence supports a limited, domain-specific comparison within this trial’s conditions.
Read our analysis of quality-of-life outcomes in a separate adult ADHD trial.
Functional outcomes from a head-to-head, randomized, double-blind trial of lisdexamfetamine dimesylate and atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder and an inadequate response to methylphenidate. doi:10.1007/s00787-015-0718-0.