Now assess your clients to age 18 years assuring confidence in your clinical decision making, while helping you plan effective intervention. The new Beck Youth InventoriesTM -Second Edition (BYI-II) for Children and Adolescents are designed for children and adolescents aged 7 to 18 years. Five self-report inventories can be used separately or in combination to assess symptoms of depression, anxiety, anger, disruptive behaviour and self-concept.