Book excerpt: This guide was created to promote the early identification of children and adolescents with mental health and substance use problems as well as to provide guidance, tools, and resources for early identification--including a compendium of the most developmentally, culturally, and environmentally appropriate screening instruments. SAMHSA developed the guide using the input of the members of the Federal/National Partnership* (FNP) Early Identification Workgroup, chaired by representatives from the Centers for Disease Control and Prevention (CDC) and the Health Resources and Services Administration (HRSA).