Sixteen-month evaluation of depressive symptomatology in older adults

Eight-Year Depressive Symptom Trajectories and Incident Stroke: A 10-Year Follow-Up of the HRS (Health and Retirement Study)

Background:

Evidence suggests a link between depressive symptoms and risk of subsequent stroke. However, most studies assess depressive symptoms at only one timepoint, with few examining this relationship using repeatedly measured depressive symptoms. This study aimed to examine the relationship between depressive symptom trajectories and risk of incident stroke.

Methods:

This prospective cohort included 12 520 US individuals aged ≥50 years enrolled in the Health and Retirement Study, free of stroke at study baseline (1998). We used the 8-item Center for Epidemiologic Studies Depression scale to assess depressive symptoms (high defined as ≥3 symptoms; low <3 symptoms) at 4 consecutive, biennial timepoints from 1998 to 2004. We assigned individuals to 5 predefined trajectories based on their scores at each timepoint (consistently low, decreasing, fluctuating, increasing, and consistently high). Using self-reported doctors’ diagnoses, we assessed incident stroke over a subsequent 10-year period from 2006 to 2016. Cox regression models estimated the association of depressive symptom trajectories with risk of incident stroke, adjusting for demographics, health behaviors, and health conditions.

Results:

During follow-up, 1434 incident strokes occurred. Compared with individuals with consistently low symptoms, individuals with consistently high depressive symptoms (adjusted hazard ratio, 1.18 [95% CI, 1.02–1.36]), increasing symptoms (adjusted hazard ratio, 1.31 [95% CI, 1.10–1.57]), and fluctuating symptoms (adjusted hazard ratio, 1.21 [95% CI, 1.01–1.46]) all had higher hazards of stroke onset. Individuals in the decreasing symptom trajectory group did not show increased stroke risk.

Conclusions:

Depressive symptom trajectories characterized by high symptoms at multiple timepoints were associated with increased stroke risk. However, a trajectory with depressive symptoms that started high but decreased over time was not associated with higher stroke risk. Given the remitting-relapsing nature of depressive symptoms, it is important to understand the relationship between depressive symptoms and stroke risk over time through repeated assessments.

Depressive symptoms do not discriminate: racial and economic influences between time-varying depressive symptoms and mortality among REGARDS participants

PURPOSE

Depressive symptoms relapse and remit over time, perhaps differentially by race and income. Few studies have examined whether time-varying depressive symptoms (TVDS) differentially predict mortality. We sought to determine whether race (white/black) and income (</≥$35,000) moderate the association between TVDS and mortality in a large cohort.

METHODS

The REGARDS study is a prospective cohort study among community-dwelling U.S. adults aged 45 years or older. Cox proportional hazard models were constructed to separately analyze the association between mortality (all cause, cardiovascular death, noncardiovascular death, and cancer death) and TVDS in race and income stratified models.

RESULTS

Point estimates were similar and statistically significant for white (aHR = 1.24 [95% CI: 1.10, 1.41]), black (aHR = 1.26 [95% CI: 1.11, 1.42]), and low-income participants (aHR = 1.28 [95% CI: 1.16, 1.43]) for the association between TVDS and mortality. High-income participants had a lower hazard (aHR = 1.19 [95% CI: 1.02, 1.38]). Baseline depressive symptoms predicted mortality in blacks only (aHR = 1.17, 95% CI: [1.00, 1.35]).

CONCLUSIONS

We found that TVDS significantly increased the immediate hazard of mortality similarly across race and income strata. TVDS may provide more robust evaluations of depression impact compared with the baseline measures, making apparent racial disparities cited in the extant literature a reflection of the imperfection of using baseline measures.

Comparing Variability, Severity, and Persistence of Depressive Symptoms as Predictors of Future Stroke Risk

OBJECTIVE

Numerous studies show that depressive symptoms measured at a single assessment predict greater future stroke risk. Longer-term symptom patterns, such as variability across repeated measures or worst symptom level, might better reflect adverse aspects of depression than a single measurement. This prospective study compared five approaches to operationalizing depressive symptoms at annual assessments as predictors of stroke incidence.

DESIGN

Cohort followed for incident stroke over an average of 6.4 years.

SETTING

The Adult Changes in Thought cohort follows initially cognitively intact, community- dwelling older adults from a population base defined by membership in Group Health, a Seattle-based nonprofit healthcare organization.

PARTICIPANTS

3,524 individuals aged 65 years and older.

MEASUREMENTS

We identified 665 incident strokes using ICD codes. We considered both baseline Center for Epidemiologic Studies-Depression scale (CES-D) score and, using a moving window of three most recent annual CES-D measurements, we compared most recent, maximum, average, and intra-individual variability of CES-D scores as predictors of subsequent stroke using Cox proportional hazards models.

RESULTS

Greater maximum (hazard ratio [HR]: 1.18; 95% CI: 1.07-1.30), average (HR: 1.20; 95% CI: 1.05-1.36) and intra-individual variability (HR: 1.15; 95% CI: 1.06-1.24) in CES-D were each associated with elevated stroke risk, independent of sociodemographics, cardiovascular risks, cognition, and daily functioning. Neither baseline nor most recent CES-D was associated with stroke. In a combined model, intra-individual variability in CES-D predicted stroke, but average CES-D did not.

CONCLUSIONS

Capturing the dynamic nature of depression is relevant in assessing stroke risk. Fluctuating depressive symptoms may reflect a prodrome of reduced cerebrovascular integrity.

Relationship between depressive symptoms and cognition in older, non-demented African Americans

Knowledge of the relationship between depressive symptoms and cognition in older adults has primarily come from studies of clinically depressed, functionally impaired or cognitively impaired individuals, and in predominately White samples. Limited minority representation in depression research exposes the need to examine these associations in more ethnic/racially diverse populations. We sought to examine the relationship between depressive symptoms and cognition in a sample of non-demented older African Americans recruited from surrounding U.S. cities of New York, Greensboro, Miami, and Nashville (N=944). Depressive symptoms were evaluated with the Geriatric Depression Scale (GDS). Cognition was evaluated with a comprehensive neuropsychological battery. Test scores were summarized into attention, executive function, memory, language, and processing speed composites. Controlling for age, education, reading level, and sex, African American older adults who endorsed more symptoms obtained significantly lower scores on measures of memory, language, processing speed, and executive functioning. Further investigation of the causal pathway underlying this association, as well as potential mediators of the relationship between depressive symptoms and cognitive test performance among older African Americans, such as cardiovascular and cerebrovascular disease, may offer potential avenues for intervention.

Volunteering and depressive symptoms among residents in a continuing care retirement community

This descriptive study examined the relationship between volunteer activities, depressive symptoms, and feelings of usefulness among older adults using path analysis. Survey data was collected via interview from residents of a continuing care retirement community. Neither feelings of usefulness nor volunteering were directly associated with depressive symptoms. Volunteering was directly associated with feelings of usefulness and indirectly associated with depressive symptoms through total physical activity. Age, fear of falling, pain, physical activity, and physical resilience explained 31% of the variance in depressive symptoms. Engaging in volunteer work may be beneficial for increasing feelings of usefulness and indirectly improving depressive symptoms among older adults.