Association between depressive symptoms and all-cause mortality in Chilean adult population: prospective results from two national health surveys

PURPOSE: Depression is a prevalent disorder with effects beyond mental health. A positive association with mortality has been mostly reported, however, evidence comes from a few high-income countries. This study aims to assess the association between depressive symptoms and all-cause mortality in the Chilean population and assess a potential secular effect in this association. METHODS: This prospective study used data from the Chilean National Health Survey (CNHS). Data from 3151 and 3749 participants from the 2003 and 2010 CNHS, respectively, were linked to mortality register data. Cox survival analysis was performed. The main exposure was depressive symptoms, measured with CIDI-SF (cut-off ≥ 5), and the outcome all-cause mortality. The study period was limited to 8.5 years to allow for the same length of follow-up. RESULTS: 10% and 8.5% of participants from the 2003 and 2010 cohort died during the follow-up. Adjusting for age and sex, those with depressive symptoms had 1.58 (95% CI 1.18-2.13) and 1.65 (95% CI 1.14-2.12) times the risk to die than those without symptoms in the 2003 and 2010 cohort, respectively. In models adjusted for demographic, socioeconomic, behavioural variables and comorbidities, participants with depressive symptoms had 1.42 (95% CI 1.05-1.92) and 1.46 (95% CI 1.07-- 1.99) times the risk to die compared to those without symptoms in the 2003 and 2010 cohort, respectively. CONCLUSION: Chilean adults with depressive symptoms are at higher risk of all-cause mortality compared to those without symptoms. The effect size was similar regardless of the economic development of the country.