OBJECTIVE: The aim of the study was to examine different models of the
factor structure of negative symptoms in schizophrenia through the use of a
confirmatory factor analysis procedure. METHOD: The cohort comprised 253
inpatients diagnosed with schizophrenia according to DSM- III-R criteria.
Negative symptoms were evaluated with the Scale for the Assessment of
Negative Symptoms (SANS). Seven alternative models of negative symptoms
were compared by means of confirmatory factor analysis. RESULTS: The
unidimensional model fit the data modestly. More complex multifactorial
models fit the data better than simpler models. Both five-dimension models
corresponding to the original SANS structure fit the data quite well; the
model excluding inappropriate affect from the SANS was the best adjusted.
CONCLUSIONS: Multidimensional models fit the data better than the
unidimensional model. The data provide evidence for the factorial validity
of the SANS and the characterization of the SANS subscales as true
underlying dimensions of observable negative symptoms.