The ADHD-200 Sample is a grassroots initiative, dedicated to accelerating the scientific community’s understanding of the neural basis of Attention Deficit Hyperactivity Disorder (ADHD) through the implementation of open data-sharing and discovery-based science. Towards this goal, the ADHD-200 consortium has publicly released 776 resting-state fMRI and anatomical datasets aggregated across 8 independent imaging sites, 491 of which were obtained from typically developing individuals and 285 in children and adolescents with ADHD (ages: 7-21 years old). Accompanying phenotypic information includes: diagnostic status, dimensional ADHD...