Child and adolescent psychotherapy research: developmental issues.

Describes developmental issues that pose current challenges to the design of treatment outcome investigation with children and adolescents. Normal childhood development and the development of childhood disorders are discussed using the transactional model of development. Challenges in diagnostic decision making, the selection of the most appropriate treatment regimen, and the measurement methods are highlighted. Recognition of the need to study child treatments through long-term follow-up periods underscores the need for resolution of these developmental issues.