Behavioral validation of avolition in schizophrenia

Clinical rating scales of negative symptoms show moderate to good concurrent validity as measures of avolition in schizophrenia. However, patients' self-reports do not appear to provide valid indices of avolition. Our results favor clinical negative symptoms scales that use observers' reports only, over patients' self-reports. The direct observation of patients' behavior offers a precise and objective measure of avolition that may be useful in drug challenges and clinical trials.