This study employs a retrospective cohort family study for the association between mood and other mental and physical disorders in probands and their relatives. Probands and relatives will be evaluated using structured diagnostic interviews and standardized diagnostic criteria followed by clinical validation interviews and diagnostic consensus procedures. Assessment instruments will collect information on the DSM-IV criteria as well as the spectrum of mood disorders and comorbid conditions. A subset of families will receive more comprehensive evaluation of clinical, laboratory, and other functional domains to identify biologic markers and endophenotypes for mood and related disorders.