Life weariness, suicidal thoughts and mortality: a sixteen-year longitudinal study among men and women older than 60 years

BACKGROUND: Suicide in old age is a significant contributor to mortality. However, the extent to which life weariness and suicidal thoughts impact on mortality in a long-term perspective is unknown. The aim of this study was to investigate the effect of life weariness and suicidal thoughts on long-term survival (16 years) in an older Swedish population, controlling for demographic and social network factors and depression. A further aim was to investigate differences in sex and age interactions in relation to mortality among individuals with and without life weariness and suicidal thoughts. METHODS: A longitudinal cohort study on a national, representative sample of individuals aged 60+ years was conducted within the Swedish National Study of Aging and Care study. The sample included 7213 individuals, who provided information about life weariness and suicidal thoughts through an item derived from the Montgomery-Åsberg Depression Rating Scale. Data were analysed with multivariate Cox proportional hazards models, adjusted for potential confounders. RESULTS: At baseline, 12.5% of the participants (14.6% of females and 9.5% of males) reported life weariness and suicidal thoughts. During the 16-year follow-up, a mean survival time was 11.5 years (standard deviation (SD) 5.6), and 3804 individuals died (59.5% females and 40.5% males). Individuals with life weariness and suicidal thoughts had half the survival rate compared with those without such thoughts (24.5% vs. 50.6%), with a mean survival time of 8.4 years (SD 5.7) versus 12.0 years (SD 5.4). The multi-adjusted hazard ratio of mortality for those reporting life weariness and suicidal thoughts was 1.44 (95% confidence interval, 1.30-1.59), with the population attributable risk at 11.1%. In the models, being male or female 80+ years showed the highest multi-adjusted hazard ratio of long-term mortality (ref. female 60-69 years). CONCLUSIONS: The findings suggested that life weariness and suicidal thoughts were risk factors for long-term mortality, when controlled for sex and age interactions that were found to strongly predict long-term mortality. These findings have practical implications in prevention of mortality, emphasising the importance of screening, identifying, and intercepting older men and women with signs of life weariness and suicidal thoughts. TRIAL REGISTRATION: Not applicable.