Intervention research in psychosis: issues related to clinical assessment.

This article discusses efforts to optimize clinical assessment for intervention effectiveness trials. Generalizability is a crucial issue; investigators should choose their inclusion/exclusion criteria to increase subject inclusion and should collect data on the selection process to determine the extent of selection biases. Intervention research requires assessment instruments appropriate for a variety of treatment settings. We describe the Hillside Clinical Trials version of the Scale for the Assessment of Negative Symptoms, which has inpatient and outpatient versions to accommodate the different opportunities for social interaction in these settings. Lack of uniformity in assessment instruments complicates interpretation of results across studies and impedes communication of findings. We describe the 5-Dimensional Scale to Evaluate Psychopathology in Schizophrenia (5-STEPS), a collaborative effort to develop a standard change measure for schizophrenia treatment trials. We also discuss potential future strategies, including developing briefer yet reliable and valid diagnostic procedures, making trials more acceptable in a broad range of settings through the use of open-label treatment with blinded independent assessors, bridging efficacy and effectiveness designs by studying both a narrow efficacy and a broader effectiveness population simultaneously, and updating outcome domains to reflect current treatment strategies.