Negative symptoms in Alzheimer's disease: a confirmatory factor analysis.
OBJECTIVE
To examine different conceptual models of negative symptoms in Alzheimer's disease.


METHODS
Confirmatory factor analysis of cross-sectional data.


METHODS
Alzheimer patients (n=281) admitted to a psychogeriatric observation ward.


METHODS
Nurses' Behavioural observation scale for psychogeriatric inpatients (GIP). Global clinical ratings of severity of dementia and depression based on the Cambridge Examination for Mental Disorders of the Elderly-Dutch version (CAMDEX-N).


RESULTS
A unidimensional model of dementia fitted the data poorly. Multidimensional models produced better results. In two- and three-factor models negative symptoms were separated from cognitive impairment and mood disturbances. The more severe the memory impairment, the more socially withdrawn patients were. In this sense negative symptoms may have been secondary to cognitive decline. However, no association was found between negative symptoms and mood disturbances.


CONCLUSIONS
Negative symptoms are a prominent clinical feature of Alzheimer's disease and they are related to memory impairment but not to mood disturbances.
de Jonghe
Jos F M
JF
Medical Center Alkmaar, Department of Clinical Psychology Alkmaar, The Netherlands. j.de.jonghe@mca.nl
Goedhart
Arnold W
AW
Ooms
Marcel E
ME
Kat
Martin G
MG
Kalisvaart
Kees J
KJ
van Ewijk
Wouter M
WM
Ribbe
Miel W
MW
D000342:Affective Symptoms / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D003072:Cognition Disorders / Q000523:psychology*; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales / Q000592:standards; D011595:Psychomotor Agitation / Q000523:psychology*; D012680:Sensitivity and Specificity