Neuroticism, loneliness, all-cause and cause-specific mortality: A 17-year study of nearly 500,000 individuals

Background: Neuroticism is related to mental and physical health. This study examined whether neuroticism and its underlying components were associated with risk of all-cause and cause-specific mortality. Methods: Community-dwelling adults (N = 491,323) in the UK Biobank completed a neuroticism scale between 2006 and 2010. Vital status was tracked up to December 2022 via linkage with the UK National Health Service. Results: Over 17 years of follow-up, 43,400 (8.8 %) participants died. Accounting for age, sex, and ethnicity, participants who scored 1 SD higher on neuroticism had a 10 % greater risk of dying (HR = 1.10, 95%CI = 1.09-1.11), an association that remained significant but was explained partly by socioeconomic status, health behaviors, and chronic conditions. Item-level analyses found that loneliness was the neuroticism item most predictive of mortality (HR = 1.46, 95%CI = 1.43-1.49), especially in males. Neuroticism and loneliness were more predictive of mortality among relatively younger adults and those with lower education. Among the causes of death, neuroticism and loneliness had the strongest association with deaths due to intentional self-harm, respiratory and digestive system diseases. Limitations: Loneliness was assessed with a single item. The associations could be due to increases in neuroticism and loneliness approaching death. However, contrary to expectations from reverse causality, the associations were similar when excluding deaths within the first five or ten years of follow-up. Future research should examine whether findings from this high-income country replicate in middle- and lower-income communities. Conclusions: Loneliness was the component of neuroticism most strongly associated with premature mortality, including from intentional self-harm, respiratory, and digestive system causes of death.