Medical Practice Variations in Mental Health and Addictions Care

International audience; This chapter provides an overview of the practice variations in care delivery for mental health and addictive disorders and some of the system-level funding and structural factors that contribute to such variation. Practice variations are described for five populations, along with their expected clinical picture and service needs:Children and adolescentsThe elderlySevere mental illnessMild/moderate illnessSubstance use disordersThese variations occur in a system-level climate which has been transformed over the past decades because of a fundamental change in how appropriate care is defined. Specifically, Western countries have been shifting from institutional to more community-based care – a process labeled “deinstitutionalization.” National differences in how services are funded and organized in light of deinstitutionalization are described. Pending gold-standard outcome indicators such descriptions allow more in-depth examination of what the potential drivers for system change are and how different funding and structure configurations might be compared and evaluated.