Clinically significant depressive symptoms and very mild to mild dementia of the Alzheimer type

Objective To compare depressive symptoms reported by persons with very mild or mild dementia of the Alzheimer type (DAT) with those reported for the person by a collateral source. Design Cross‐sectional evaluation. Setting Washington University Alzheimer's Disease Research Center. Participants Consecutive series of elderly volunteers (n = 156) enrolled in longitudinal studies with a Clinical Dementia Rating (CDR) of 0.5 (very mild) or 1 (mild). Twenty‐one per cent (n = 33) exhibited clinically significant depressive symptoms for which treatment was recommended. Main outcome measures Presence and frequency of DSM‐IV depressive symptoms within the last year and last month reported by the participant or collateral source as ascertained by clinical examination and structured interviews. Results Collateral source information is essential in diagnosing clinically significant depressive symptoms. The Geriatric Depression Scale scores correlate with participant information only and therefore may substantially underestimate depression. Depressive symptoms fluctuate in individuals with DAT. The most consistent depressive symptoms are depressed mood, fatigue and indecision. Conclusions Clinically significant depressive symptoms may be common in individuals with very mild or mild DAT, although they may fluctuate. Information from both a knowledgeable collateral source and the participant is important for detection of depressive symptoms. Copyright © 2001 John Wiley & Sons, Ltd.