Objectives: ADHD in young adults is associated with significant impairment in multiple functional domains. This trial examined the efficacy of atomoxetine (ATX) in young adults and evaluated improvements in core ADHD symptoms and associated functional outcomes.
Method: Patients aged 18-30 years were randomized to 12 weeks of double-blind treatment with ATX (n=220) or placebo (PBO, n=225). Patients in the atomoxetine treatment arm began treatment with 40 mg/day (dosed 20 mg BID) for a minimum of 7 days followed by 80 mg/day (dosed 40 mg BID) for a minimum of 7 days. At Visit 5, or any visit thereafter, the dose could be increased to the maximum of 100 mg/day (dosed 50 mg BID) depending upon continued ADHD symptoms. One unscheduled dose change was allowed if needed for tolerability or safety. The Conners' Adult ADHD Rating Scale- Investigator Rated, Screening Version Total ADHD Symptoms score (CAARS – Inv:SV) with adult ADHD prompts, assessed core ADHD symptoms and was the primary efficacy measure. The adult ADHD Quality of Life-29 (AAQOL-29) scale evaluated functional outcomes in various life domains. Other assessments included Clinical Global Impression-ADHD-Severity (CGI-ADHD-S), CAARS Self Report (CAARS-S:SV), Patient Global Impression-Improvement (PGI-I), Behavior Rating Inventory of Executive Function-Adult Version Self Report (BRIEF-A), and measures for depression, anxiety, sleepiness, driving behaviors, social adaptation, and substance use. Reported means are least-squares means from last-observation-carried-forward ANCOVA models. A mixed-model repeated measures visit-wise analysis was also conducted.
Results: Significant improvement (mean±SE) after ATX treatment was demonstrated on CAARS-Inv:SV (ATX [-13.6±0.8] vs. PBO [-9.3±0.8], p<.001), AAQOL-29 (ATX [14.8±1.1] vs. PBO [10.6±1.1], p<.001), CGI-ADHD-S (ATX [-1.1±0.1] vs. PBO [-0.7±0.1], p<.001), CAARS-S:SV (ATX [-11.9±0.8] vs. PBO [-7.8±0.7], p<.001), and on most components of BRIEF-A, but not PGI-I. Additional assessments were not significant (p>0.05). The adverse event profile in this study was similar to that observed in other ATX studies.
Conclusion: ATX improved core ADHD symptoms with respect to PBO in young adults. Several functional outcomes and executive functioning measures improved significantly with ATX treatment. ATX was generally well-tolerated.