Diagnosis, assessment, and comorbidity in psychosocial treatment research.

This paper identifies problems in prevailing terminology and conceptual models that may hinder research on treatment. To avoid the multiple meanings of diagnosis, the term assessment is used in reference to identifying the distinguishing features of individual cases, while taxonomy is used to designate the grouping of cases according to their distinguishing features. Treatment research requires clear specification of the behavioral/emotional problems and competencies targeted for intervention. Artifactual comorbidity can be avoided by specifying treatment targets at several levels, including competencies, specific problems, syndromes, profiles of syndrome scores, and global problem scores. To select subjects for treatment research and to evaluate outcomes, multisource data can be coordinated by using a cross-informant computer program, taxonomic decision tree, and averaging of multisource standard scores.