BackgroundMental health problems account for 14% of mortality worldwide. The aim of this study was to evaluate the association between psychological distress and mortality in the Spanish adult population. MethodsData came from a longitudinal study in population ≥15 years of age (n=21,005) who participated in the 2011-12 Spanish National Health Survey, which was linked to mortality records as of December 2020. Mental health was assessed with the GHQ-12, defining psychological distress as a dichotomous variable using a GHQ-12 score ≥3 as the cutoff point. Using Poisson regression, standardized mortality rate ratios (SRR) were estimated for all-cause, cardiovascular disease, and tumor-related mortality, adjusting for sociodemographic variables, lifestyles, and comorbidities. ResultsThe standardized overall mortality rate in individuals with and without psychological distress was 14.58 and 10.90 per 1000 person-years, respectively, estimating an SRR of 1.34 (95%CI: 1.19–1.50). The SRR for tumor-related mortality was 1.17 (95%CI: 0.90–1.53), and cardiovascular-related mortality was related to higher distress (GHQ-12 ≥ 4): SRR of 1.22 (95%CI: 0.98–1.51). Among psychological distressed individuals, the overall mortality SRR for those with a previous mental disorder diagnosis was 1.18 (95%CI: 0.91–1.53) versus 1.34 (95%CI: 1.18–1.54) for those without such diagnosis (p for interaction=0.067). Similarly, distressed participants taking prescription drugs for mental disorders had a lower mortality risk than those not taking them (p for interaction=0.016). ConclusionsIndividuals with psychological distress had a higher risk of overall-, cardiovascular disease- and tumor-related mortality. This association was higher among participants not previously diagnosed with a mental disorder and those not taking medication for mental issues.