Validity of specific subscales of the positive and negative symptom scales in older schizophrenia outpatients.
We investigated the construct validity of subscales of the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) along with other measures of psychopathology in 109 schizophrenia outpatients aged 45-84 years. Scores on subscales of the SAPS, SANS and Brief Psychiatric Rating Scale (BPRS) and on the Hamilton Depression Scale (HAM-D) were subjected to a principal components analysis and orthogonal rotation followed by an extension analysis. In both analyses, three of four SAPS subscales had their highest loading on the positive symptom factor and four of five SANS subscales had their highest factor loading on the negative symptom factor. The SAPS bizarre behavior subscale, however, had a much higher loading on the depressive symptom factor than on the positive symptom factor, and the SANS avolition-apathy subscale had moderate loadings on both the negative symptom factor and the depressive symptom factor. The use of SAPS and SANS subscales to represent two constructs was largely (but not entirely) validated among middle-aged and elderly schizophrenia outpatients. The SAPS bizarre behavior subscale and, to a lesser extent, the SANS avolition-apathy subscale appear to represent in this older population a separate construct which may be related to depressive symptoms.
McAdams
L A
LA
Department of Psychiatry, University of California, San Diego, USA. LouAnn_McAdams@GP-POST.ucsd.edu
Harris
M J
MJ
Heaton
S C
SC
Bailey
A
A
Fell
R
R
Jeste
D V
DV
D000367:Age Factors; D000368:Aged; D000553:Ambulatory Care; D010054:Brief Psychiatric Rating Scale / Q000706:statistics & numerical data; D005163:Factor Analysis, Statistical; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology