The paper outlines the growing acceptance and use of multimodal treatment approaches to treat a variety of psychiatric disorders in childhood and adolescence. It then explores some of the problems of multimodal treatment studies. Problems in assessing outcome of efficacy of the interventions, particularly as they pertain to specific interventions and particular areas of functioning are discussed as well as the issues of appropriate control and comparison groups. The problems with regard to appropriate control and comparison groups are explored with respect to diagnosis and interventions. Finally, an ongoing multimodal treatment study of children with attention deficit hyperactive disorder is used to illustrate how some of the problems described can be solved.