Recent findings indicate an increased concern that conventional substance abuse treatment models consistently reflect less than satisfactory outcomes when applied to adolescents. This study investigates developmental differences among adolescents and adults as a possible cause of the disparity. The author conducted interviews with substance abuse professionals, developmental psychologists, adolescents in treatment, and adolescents no less than six months out of treatment. Questions focus on assessment agendas, developmental and motivational differences among adolescents and adults, movement along the addiction continuum, developmental tasks of adolescence, and adolescent receptivity. The results of the interviews among each group are compared and consistencies are noted. The implications of any correlation within the noted consistencies are discussed, as well as the implications for social work practice.