Attention Deficit Hyperactivity Disorder (ADHD) is a serious public health problem that affects between 3 to 9% of children and accounts for between 30 to 40% of child referrals to mental health services. While the cause of this illness remains poorly understood, ADHD is increasingly seen as a neurodevelopmental disorder. This work promises to identify where in the brain and at what age certain alterations occur in children and adolescents with ADHD, and this information of changes with age can then potentially be used as a predictor of treatment outcome. View more information on ADHD.