Depressive symptom trajectories in older adults with dementia and associated risk of functional decline

Background: Despite the dynamic nature of depressive symptoms, many studies have failed to capture change in symptoms over time, thus limiting our understanding of the burden, course and outcomes of depression among vulnerable populations such as those with dementia. We examined the course of depressive symptoms and associated risk of functional decline over 1-year among a large sample of older home care (HC) clients with a diagnosis of Alzheimer's disease or related dementia. Method(s): Longitudinal clinical data from the Resident Assessment Instrument for Home Care (RAI-HC) were linked to provincial administrative health databases. We examined assessments performed by trained case managers among all Ontario HC clients between 2006 and 2009. The sample was restricted to clients (mean age 82 yrs; 73% female) with dementia and 3 consecutive assessments who remained alive during the year post-3rdassessment (n=16,597). Clinically important depressive symptoms were captured by the RAI-HC depression rating scale (DRS score 3+) and categorized as no symptoms (no DRS score of 3+ at any point), baseline-only, new onset (at 1st or 2nd reassessment but not at baseline), or persistent (at baseline and 1st or 2nd follow-up assessment). Associations between depressive symptom change and functional decline (i.e., decline in ADL scores and/or admission to long-term care) over 1-year were examined with multivariable logistic regression models adjusted for relevant confounders. Result(s): In models adjusted for age, sex, antidepressant use, severity of cognitive impairment, co-existing neurological and chronic health conditions and previous acute care use, clients with new onset depressive symptoms [9.5% of sample] were significantly more likely than those with no symptoms to exhibit functional decline [adj. OR=1.40, 95%CI 1.25-1.56]. Clients with persistent depressive symptoms [9.5%] showed a marginally increased risk of functional decline [adj. OR=1.14, 95%CI 1.02-1.27] whereas those with baseline only symptoms [5.1%] showed no increase in risk. Conclusion(s): Older adults with dementia and new depressive symptoms appear to be at particular risk of functional decline. Our findings indicate the need for coordinated efforts to improve the timely identification and treatment of depressive symptoms (beyond a one-time assessment) and the underlying contributing factors among persons with dementia in community settings.

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