Impact of Alzheimer's-type dementia and information source on the assessment of depression.

Abstract

Assessment of depression in patients with Alzheimer's disease (AD) is complicated by uncertainty regarding the accuracy of information supplied by the patient and collateral informants. Agreement between these two sources in completing the Hamilton Rating Scale for Depression (HRSD; M. Hamilton, 1960) was compared in patients with AD (n = 185) and two groups of nondemented outpatients: patients with Parkinson's disease (n = 57) and geriatric referrals (n = 54). The correlation between HRSD scores generated from structured interviews with patients and collateral sources was attenuated in AD (r =.29) in comparison with Parkinson's disease (r =.92) and geriatric outpatients (r =.85). Differences in scores between interview methods in AD reflected a generally low rate of symptom endorsement by patients. These findings highlight the potential insensitivity of patient report in AD and support the use of collateral informants as an alternative source of clinical information in persons with significant cognitive impairment