Among the criteria for diagnosis, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), a depressed or irritable mood must persist for at least one year in children or adolescents and must be accompanied by at least two other symptoms listed above, with no longer than a two-month period without symptoms being present. These symptoms must result in clinically significant distress or impairment in social, occupational, academic, or other major areas of functioning.