To optimize the impact of SBIRT and other efforts to provide prevention services for adolescents and young adults, it is critical to identify which youth are potentially at risk and would benefit from interventions.  Screening is quick, easy process designed to identify which youth are potentially at-risk, and which youth are not using alcohol and drugs and therefore do not need any further services related to substance use. The most commonly used screening tools are brief, address both alcohol and drugs, easy to administer, and empirically proven to have good sensitivity (capacity to detect when youth are at risk) and specificity (capacity to detect when youth are not at risk).