Clinical response and symptomatic remission in children treated with lisdexamfetamine dimesylate for attention-deficit/hyperactivity disorder

Objective: To examine clinical response and symptomatic remission in two studies of lisdexamfetamine dimesylate (LDX) in children with attention-deficit/hyperactivity disorder (ADHD). Methods: In a 4-week, placebo-controlled, double-blind trial, children 6-12 years of age with ADHD received LDX (30-70 mg/day) or placebo. In an open-label trial, children from previous studies were titrated to optimal dose over 4 weeks and maintained up to 1 year. Primary and secondary efficacy assessments were the ADHD Rating Scale IV (ADHD-RS-IV) and Clinical Global Impressions-Improvement (CGI-I) scale, respectively. Clinical response was defined as ≥30% reduction in ADHD-RS-IV total score with a CGI-I rating of 1 or 2; symptomatic remission was defined by ADHD-RS-IV total score ≤18. Results: In the 4-week study (N=285), at any postdose assessment, 79.3% achieved response (median 13 days) and 67.1% achieved remission (median 22 days) with LDX versus 29.2% and 23.6% with placebo. In the long-term study (N=251), at any postdose assessment, 96.0% responded and 62.7% maintained response; 88.8% achieved remission and 46.4% maintained remission. Conclusion: Most children treated with LDX achieved clinical response and symptomatic remission at one time point; once achieved, almost half maintained remission.