Association between self-reported depression and risk of all-cause mortality and cause-specific mortality

Depression is a prevalent and disabling mental disorder that frequently co-occurs with a wide range of chronic conditions. Past evidence suggests that depression could be associated with the all-cause mortality and other disease mortality in Western populations, but little is known about the relationship in the Chinese population. Therefore, we investigated the associations between self-reported depression and all-cause and specific-cause mortality in Chinese adult populations.

The Patient Health Questionnaire-9 (PHQ-9) was used to measure depressive symptoms among 8,151 adult participants drawn from the general population of Guizhou province, China. Participants death and cause of death were determined by linking with the official death records and certificates up to June 2021. Cause of death was coded according to ICD-10 then categorized as either cardiovascular disease (CVD, I00-I99), cancer (C00-C97) or other cause. Cox proportional hazard regression was used to examine the associations of self-reported depression with all-cause mortality and cause-specific mortality.

With a median follow-up of 7.4 years, 8,151 participants (52.6% women) at baseline were included in the analysis. The multivariable cox hazard regression models showed that participants with moderate and major depression had the highest hazard ratio (HR) for risk of all-cause mortality (HR=5.65, 95% CI 3.09-10.33), CVD mortality (HR=5.66, 95% CI 2.02-15.84), and cancer mortality (HR=7.21, 95% CI 2.00-25.99), compared with participants had no or mild depression.

Our findings suggested that depression was a risk factor for mortality, with greater risk for greater severity. Clinicians should be aware of the increased risk of mortality in populations with depression.