Spanish adaptation and validation of the Brief Negative Symptoms Scale.

Negative symptoms prevalent in schizophrenia are associated with poor outcome. Developing new instruments to identify new treatments was highlighted at the NIMH-MATRICS Consensus Development Conference on Negative Symptoms. The new Brief Negative Symptoms scale (BNSS) demonstrated strong psychometric properties, but there is a need for validating it in non-English languages. A multi-center study was conducted to validate the Spanish version of the BNSS (BNSS-Sp) in 20 schizophrenia patients, following the original BNSS validation methodology. We found strong inter-rater, test-retest and internal consistency properties (for the total BNSS-Sp, intraclass correlation coefficient=0.97, Pearson's correlation coefficient r=0.95 (p<0.001), Cronbach's alpha=0.98).