Depressive symptoms in Alzheimer's disease and lewy body dementia: a one-year follow-up study.

OBJECTIVE

To explore the course of depression in people with mild dementia and identify predictors for depression at 1-year follow-up.

METHODS

Patients with mild dementia (n = 199) were assessed using Montgomery and Åsberg Depression Rating Scale (MADRS) and the depression item from Neuropsychiatric Inventory (NPI) at baseline and after 1 year. A score above 6 on MADRS indicates at least mild depression. Linear and logistic regression analyses were performed to identify predictors of change in depression scores.

RESULTS

Among subjects with depression at baseline, 68.1% remained depressed at follow-up, whereas 31.9% had remitted, based on MADRS. Among patients without depression at baseline, 77.1% remained non-depressed at follow-up, whereas 22.9% had incident depression. The proportion with persistent depression was higher in the combined dementia with Lewy bodies (DLB)/Parkinson's disease with dementia (PDD) group (45.5%) compared to AD (28%) (p < 0.05). Greater decline on the Mini Mental State Examination (p < 0.001) and higher baseline MADRS score (p < 0.001) were significant predictors of increased MADRS score.

CONCLUSION

Two thirds of patients with depression at baseline were still depressed at follow-up, more so in DLB with PDD compared to AD. Cognitive decline was associated with worsening of depressive symptoms.