Evidence-based practices (EBPs) are designed to address specific needs. In many cases, the extent to which these practices successfully address those needs, as evidenced by improved and desired outcomes, determines whether or not they will be sustained. Often, programs will be sustained despite lack of evidence of positive outcomes. In either case, the decision whether or not to adopt a specific program or practice is determined by the availability or supply of services to address a specific need, the demand (that is, number of clients or patients) for that service, and the fit between the practice, the organization responsible for its use, and the patients or clients who are its intended beneficiaries.

In this chapter, we begin with an examination of the need for evidence-based mental health services among youth in general and child-welfare involved youth in particular. We begin with a review of the current state of our understanding of this need among youth in general, focusing on the prevalence of mental and behavioral health problems in this population and the risk of these problems associated with the experience of childhood adversities such as child maltreatment, poverty, racism and discrimination, and involvement in criminal justice systems. We then narrow our focus to youth involved in the child welfare system and examine both the scale and severity of their mental and behavioral health problems and limited access to services to address these problems. The chapter then introduces some of the current evidence-based programs and practices designed to address these problems, focusing on their prevention and treatment, and then concludes with a brief review of the extent to which they are utilized for this purpose.