Predictors of 30-year mortality in depressed and comparison samples

Interaction between mental disorders and social disconnectedness on mortality: a population-based cohort study

BACKGROUND

Despite the recognised importance of mental disorders and social disconnectedness for mortality, few studies have examined their co-occurrence.

AIMS

To examine the interaction between mental disorders and three distinct aspects of social disconnectedness on mortality, while taking into account sex, age and characteristics of the mental disorder.

METHOD

This cohort study included participants from the Danish National Health Survey in 2013 and 2017 who were followed until 2021. Survey data on social disconnectedness (loneliness, social isolation and low social support) were linked with register data on hospital-diagnosed mental disorders and mortality. Poisson regression was applied to estimate independent and joint associations with mortality, interaction contrasts and attributable proportions.

RESULTS

A total of 162 497 individuals were followed for 886 614 person-years, and 9047 individuals (5.6%) died during follow-up. Among men, interaction between mental disorders and loneliness, social isolation and low social support, respectively, accounted for 47% (95% CI: 21-74%), 24% (95% CI: -15 to 63%) and 61% (95% CI: 35-86%) of the excess mortality after adjustment for demographics, country of birth, somatic morbidity, educational level, income and wealth. In contrast, among women, no excess mortality could be attributed to interaction. No clear trends were identified according to age or characteristics of the mental disorder.

CONCLUSIONS

Mortality among men, but not women, with a co-occurring mental disorder and social disconnectedness was substantially elevated compared with what was expected. Awareness of elevated mortality rates among socially disconnected men with mental disorders could be of importance to qualify and guide prevention efforts in psychiatric services.

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.