Challenges and benefits of assessment, diagnosis, and taxonomy for clinical practice and research.

OBJECTIVE: To outline nosological (top-down) and empirically based (bottom-up) approaches to assessment and taxonomy of psychopathology.
METHOD: The two approaches were compared and contrasted to highlight similarities and differences between them. RESULTS AND
CONCLUSIONS: To advance services and research, we need to make optimal use of assessment data (i) to identify the distinguishing features of each case, and (ii) to link individual patterns of functioning with taxonomic constructs that can help us apply previously accumulated knowledge to new cases. The time may be ripe for integrating nosological and empirically based approaches. One way to integrate these approaches is to construct empirically based and DSM-oriented scales from the same item pools and to generate age- and gender-specific standard scores and cut-off points from the same normative samples. Integration of the approaches was illustrated with profiles of empirically based and DSM-oriented scales scored from the same item pools and quantified in relation to the same normative samples. To facilitate use by clinicians and researchers under diverse conditions, data are readily obtained on forms completed independently by parents, teachers and others. The data can be quickly scored by hand or computer. To take account of situational and informant variations, the computer software systematically compares data from multiple informants on empirically based and DSM-oriented scales.