Impact of depressive symptoms on outcome of Alzheimer's disease

Abstract

Abstract There is no consensus in the medical literature about the impact of depressive symptoms on the evolution of Alzheimer's disease (AD). Objective: To compare the evolution of AD patients, with and without depressive symptoms, in terms of cognition, functionality and caregiver stress. Methods: The study entailed 2 stages: an initial retrospective stage involving review of medical charts of patients with mild and moderate AD. Patients were divided according to the presence or absence of depressive symptoms, defined by medical interview and questions on depressed mood from the CAMDEX (Cambridge Examination for Mental Disorders of the Elderly) and Neuropsychiatric Inventory (NPI). Twenty-nine patients were evaluated, 37.9% with depression (Group D+) and 62.1% without depression (Group D-). The groups were compared regarding demographic and medical characteristics, cognitive and functional performance, presence of apathy as a separate symptom, and caregiver stress, using standardized tests and questionnaires. In the second transversal step, the same tools were reapplied after 2 to 4 years of follow-up, and evolution for the two groups was compared. Results: The two groups were highly homogeneous in demographic and clinic characteristics, as well as in length of follow-up, and presented no significant difference in cognitive or functional evaluation at the time of diagnoses or after follow-up. Only caregiver stress was greater in Group D+ at the two time points (p<0.001). Conclusions: No differences in the evolution of AD patients with or without depressive symptoms were evident. Nevertheless, these symptoms were associated to emotional burden of caregivers.

Keywords

• Alzheimer's disease
• depression
• cognition
• caregiver