Brain Imaging and Computer Games in Children With Either Bipolar Disorder, ADHD, Anxiety or Healthy Controls

General Inclusion Criteria: * English- speaking,children \& adolescents between the ages of 7- 17 * consenting parent/guardian General Exclusion Criteria: * estimated IQ less than 70 * substance/alcohol use or dependence within the last 2 months * Autism Spectrum Disorders or primary psychosis * medical/neurological conditions that mimic the psychiatric disorders of interest * implanted metal (NO BRACES or COCHLEAR IMPLANT) For inclusion in the Bipolar group, participants: * have to meet Diagnostic and Statistical Manual, 4th Edition Text Revision (DSM-IV-TR) criteria for BD Type I, including at least one lifetime episode of mania For inclusion in the ADHD/ADD group, participants: * meet DSM-IV-TR criteria for any subtype of ADHD or ADD * can not currently meet diagnostic criteria for bipolar, depressive or anxiety disorders For inclusion in the Generalized Anxiety Group (GAD), participants: * have to meet DSM-IV-TR criteria for GAD * can not currently meet diagnostic criteria for Obsessive Compulsive Disorder (OCD) or Post-Traumatic Stress Disorder (PTSD) For inclusion in the Healthy Control group, participants: * can not have a past/current history of psychiatric or substance use disorders * can not have a first-degree relative (parents, brothers/sisters) with a history of psychiatric illness