Aging
Trajectories of depressive symptoms among older adults by spousal dementia status: a sequence analysis approach Michelle Flesaker* Michelle Flesaker Flesaker Flesaker Flesaker Boston University School of Public Health
Introduction: One in 10 US older adults have Alzheimer’s Disease and Alzheimer’s Disease Related Dementias (ADRD). Spouses of people with ADRD have higher depression incidence than those without.1 Studies on depressive symptoms by spousal ADRD status have not examined complex trajectories of symptoms over time. We characterize trajectories of depressive symptoms from age 50-85 in older adults and variations by spousal ADRD status through novel applications of sequence and cluster analyses.
Method: We used data from the Health and Retirement Study (HRS), a longitudinal study of older adults in the US. We included 5,231 married people, 890 (17%) of whom had spousal ADRD. We classified each year of participants’ lives from ages 50-85 into one of the following mutually exclusive categories using the modified Center for Epidemiologic Studies-Depression Scale (0-8): no depression (0), low (1-3), high (>4), unreported, dead. We used multiple imputation to complete initial and intermediate missing data. We calculated dissimilarity between individual trajectories of depressive symptoms using sequence analysis and grouped similar sequences using cluster analysis. We quantified relationships between spousal ADRD status and resultant clusters.
Results: We identified 6 clusters of depressive symptom trajectories. Clusters varied by symptom severity, follow-up time, and survival. Spousal ADRD status was differentially distributed among clusters: more participants with spousal ADRD were in the low/moderate depression, long follow-up (Cluster 5; 31% with spousal ADRD, 69% without), high mortality (Cluster 3; 25% with spousal ADRD), and no/low depression, long follow-up clusters (Cluster 2; 25% with spousal ADRD).
Discussion: We found a different distribution of spousal ADRD by unique clusters of depressive symptoms over time in a large national sample of older adults. Future research should consider the impact of complex longitudinal depressive symptom patterns.
1. Joling KJ, van Hout HP, Schellevis FG, et al. Incidence of depression and anxiety in the spouses of patients with dementia: a naturalistic cohort study of recorded morbidity with a 6-year follow-up. Am J Geriatr Psychiatry. 2010;18(2):146-153
