Factor Structure and Construct Validity of the Scale for the Assessment of Negative Symptoms

Confirmatory factor analysis (CFA) was used to examine the underlying structure of the negative symptoms of schizophrenia as measured by the Scale for the Assessment of Negative Symptoms (SANS). Schizophrenia patients (AT = 457) were assessed with the SANS on at least I of 2 occasions: (a) 2-4 weeks after an index hospitalization, and (b) after a clinical stabilization period that lasted 3-6 months. Results of an exploratory factor analysis conducted for the first assessment (n = 401) were largely supported by the CFAs conducted on the data at the second assessment (« = 345). The CFA solution included 3 factors: Diminished Expression, Inattention-Alogia, and Social Amotivation. Analysis of patients' clinical characteristics, treatment outcome, chronicity of the illness, premorbid history, and social adjustment supported the validity of the 3 factors.