The factor structure of the Cornell Scale for Depression in Dementia among probable Alzheimer's disease patients

The authors rated 137 outpatients with probable Alzheimer's disease (AD) on the Cornell Scale for Depression in Dementia (CSDD) as part of routine evaluation. Principal-factors analysis with varimax rotation resulted in a four-factor solution that accounted for 43.1% of the common variance. The four factors included general depression (lack of reactivity to pleasant events, poor self-esteem, pessimism, loss of interest, physical complaints, psychomotor retardation sadness); rhythm disturbances (difficulty falling asleep, multiple night awakenings, early morning awakenings, weight loss, diurnal variation of mood); agitation/psychosis (agitation, mood-congruent delusions, suicide); and negative symptoms (appetite loss, weight loss, lack of energy, loss of interest, lack of reactivity to pleasant vents). The observed factor structure showed moderate concordance with the five symptom clusters proposed in the original presentation of the CSDD.