[Negative symptoms: clinical and psychometric aspects]

Recent investigations performing exploratory and confirmatory factor analysis have suggested that negative symptoms are multidimensional, including evidence for at least two distinct negative symptom subdomains: diminished expression and amotivation. Guidance for selection of instruments for measurement of negative symptoms is rapidly evolving. As there are continuing advances in the description of negative symptoms, new instruments are under development, and new data on the performance of instruments emerge from clinical trials. The Scale for Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS), and the Negative Symptom Assessment-16 (NSA-16) are considered to be reliable and valid measures for negative symptom trials but differ with respect to their domain coverage, use of informants, integration of global scores, administration time and comprehensiveness of their structured interviews. In response to the 2005 NIMH - MATRICS consensus statement, work groups are field testing and refining two new measures, the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptom Scale (BNSS). Both address the five currently recognized domains of negative symptoms, differentiate appetitive from consummatory aspects of anhedonia and address desire for social relationships. Thus far, both have exhibited promising psychometric properties.