This is a randomized, double-blind, placebo-controlled, parallel-group, efficacy and safety study in children with ADHD in a laboratory classroom setting. The study will be comprised of 3 periods: Screening (up to 35 days) including a 3 - 5 day ADHD medication washout prior to Day -1; Double-blind randomized treatment with either dasotraline (4 mg/day) or placebo for14 days; and End of Study (EOS) Visit (7 days after last dose). Prior to the start of treatment (Day 1) and following the conclusion of the double-blind period (Day 15), subjects will undergo a full-day laboratory classroom evaluation during which approximately 12 to 18 subjects will be assessed. Each laboratory classroom day will include seven 30-minute simulated classroom sessions where trained observers will assess subjects using the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) Scale. In addition during each classroom session, a 10-minute math test (Permanent Product Measure of Performance [PERMP]) will be administered to evaluate sustained attention and effort. Seven (± 2) days after the last dose of study drug, subjects will return to the clinic and complete safety assessments.