Abstract
Family-based treatments for adolescent drug abuse and related behavior problems have been developed and evaluated with success. Empirical support exists for the efficacy of family-based treatments, and process studies have begun to identify mechanisms by which these treatments may achieve their effects. This article discusses theory and related clinical refinements in a contemporary family-based intervention, multidimensional family therapy. Expansions in the theoretical basis of the model are discussed. I highlight 2 aspects of the theory evolution process, resulting in a sharper clinical focus on intrapersonal development and on adolescents' and families' functioning vis-à-vis influential extrafamilial ecologies of development.