For this protocol we define Bipolar Spectrum disorders (BSD) as the propensity to have a manic episode by having Bipolar Disorder or Substance/Medication-Induced Bipolar and Related Disorder. BSD in children and adolescents is receiving increased research attention, but important questions remain about its developmental trajectory, phenomenology and behavioral correlates, and little is known about its underlying neural mechanisms. In its study of youth with BSD, this study has three objectives: