A semi-structured interview administered by a professional and designed to yield diagnostic information about current and lifetime incidences of affective disorders and schizophrenia. Contains a series of questions and criteria which allow for the understanding of symptom severity during the lifetime, as well as the current or most recent episode, employing a 0-4, 0-6, or 0-7 scale. Also employed for diagnosis of children, using the KSADS, or Kiddie Schedule for Affective Disorders and Schizophrenia.