Diagnosis, assessment, and treatment of externalizing problems in children: the role of longitudinal data.

Prospective longitudinal studies that pertain to the stability, developmental pathways, and long-term outcome for the 2 primary forms of externalizing behavior problems (conduct problems [CP] and hyperactivity [HA]) are described. Treatment outcome studies for CP and HA with at least 1 year of follow-up data are reviewed. The implications of longitudinal research for the diagnosis, assessment, and treatment of externalizing behavior problems in children are discussed. Greater attention must be paid to issues related to comorbidity, developmentally appropriate assessments, and long-term outcome of interventions. Longitudinal-experimental investigations that serve to delineate developmental pathways as well as assess the effects of developmentally sensitive, comprehensive interventions are recommended.