Happiness and Its Association With Suicide Ideation and Attempt in Korea: The Roles of Socio-Environmental, Psychological, and Health-Related Factors.

Background: The association between happiness and suicide behaviour across different gender and age groups remains unclear, with few studies identifying potential confounding or mediating factors that explain this association. We aimed 1) to examine the association of happiness with suicide ideation/attempt and 2) to assess the relative contribution of potential factors in explaining the associations in South Korea.

Methods: We used data from the Korea Community Health Survey 2021, with 214,070 respondents aged over 20 years. Happiness was measured by using Cantril's ladder of life satisfaction. Suicide ideation and suicide attempt were each measured by a single question. A hierarchical logistic regression model was used to identify the association between happiness and suicide ideation/attempt and estimate the relative importance of each socio-environmental, psychological, and health-related factor.

Results: Unhappiness was associated with suicide ideation/attempt across gender and age groups. The associations appeared stronger in younger rather than older adults, particularly for women aged 20-39 and 40-59 years. Psychological factors contributed the most to explaining the association across all genders and age groups. Socio-environmental factors explained the associations more among individuals aged 40-59 years and health-related factors were more pronounced in explaining the association among those aged 60 years and above, compared to other age groups.

Conclusion: Unhappiness is associated with suicide ideation/attempt. Psychological factors could largely explain this association, suggesting that improving population mental health could play an important role in increasing happiness and preventing suicide behaviour.