A cohort of 100 patients with ADHD will be recruited for a 12 week, double-blind, parallel, randomized controlled trial of Lisdexamfetamine (Vyvanse) versus placebo, with 50 patients randomized to Lisdexamfetamine and the other 50 patients to placebo. The investigators will acquire high-resolution, anatomical and functional MRI images at baseline and after 12 weeks of treatment.
In addition, 75 age- and sex-matched healthy control subjects will be imaged at baseline.