The brief negative symptom scale in translation: A review of psychometric properties and beyond.

Negative symptoms are a core feature of schizophrenia and associated with social and occupational impairment. To encourage treatment development and address the limitations of existing rating instruments in this area across culture, the Brief Negative Symptoms Scale (BNSS) was developed. The authors reviewed studies published since the BNSS was published in 2010 that examined the psychometric properties of the instrument in translation and compared for consistency, psychometric performance and related features. Eleven published cross-cultural validation studies demonstrated the translated versions of the BNSS have strong psychometric properties, similar to the original English version. The internal consistency ranged from 0.88 to 0.98 and the inter-rater reliability ranged from 0.81 to 0.98 for the total score. The BNSS exhibited good convergent validity with existing measures of similar constructs and function, and good discriminant validity relative to other constructs. Recent research also reported that the BNSS is sensitive to drug effects, with effect sizes comparable to established scales. The results of confirmatory factor analyses revealed that the 5-factor structure of negative symptoms in schizophrenia (blunted affect, anhedonia, avolition, asociality, and alogia) crosses cultures. This psychometric evidence suggests that the BNSS is a valid and reliable instrument for assessing pathological mechanism underlying the negative symptoms of schizophrenia across cultures and can be a useful instrument in global clinical trials.