title: The Brief Negative Symptom Scale (BNSS): Independent validation in a large sample of Italian patients with schizophrenia.
abstract: BACKGROUND
  The Brief Negative Symptom Scale (BNSS) was developed to address the main limitations of the existing scales for the assessment of negative symptoms of schizophrenia. The initial validation of the scale by the group involved in its development demonstrated good convergent and discriminant validity, and a factor structure confirming the two domains of negative symptoms (reduced emotional/verbal expression and anhedonia/asociality/avolition). However, only relatively small samples of patients with schizophrenia were investigated. Further independent validation in large clinical samples might be instrumental to the broad diffusion of the scale in clinical research.
  
  
  METHODS
  The present study aimed to examine the BNSS inter-rater reliability, convergent/discriminant validity and factor structure in a large Italian sample of outpatients with schizophrenia.
  
  
  RESULTS
  Our results confirmed the excellent inter-rater reliability of the BNSS (the intraclass correlation coefficient ranged from 0.81 to 0.98 for individual items and was 0.98 for the total score). The convergent validity measures had r values from 0.62 to 0.77, while the divergent validity measures had r values from 0.20 to 0.28 in the main sample (n=912) and in a subsample without clinically significant levels of depression and extrapyramidal symptoms (n=496). The BNSS factor structure was supported in both groups.
  
  
  CONCLUSIONS
  The study confirms that the BNSS is a promising measure for quantifying negative symptoms of schizophrenia in large multicenter clinical studies.
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mucci
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy. Electronic address: silvana.galderisi@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Galderisi
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Merlotti
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, Section of Psychiatry, University of L'Aquila, L'Aquila, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Rossi
authors.affiliation: Department of Neuroscience, Section of Psychiatry, University of Turin, Turin, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Rocca
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Bucci
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Piegari
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Chieffi
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Vignapiano
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Maj
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000175:diagnosis* / Q000523:psychology; D010054:Brief Psychiatric Rating Scale / Q000592:standards*; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology
keywords: Avolition; Negative symptoms; Poor emotion expression; Primary negative symptoms; Schizophrenia