Relative deprivation and suicide risk in South Korea

Psychosocial stress and the related biochemical response have been hypothesized as a potential mechanism underlying the link between relative deprivation and mortality. While suicide is known as the likely manifestation of severe mental illness, less is known about the effect that relative deprivation has on suicide risk. Using the 2012 to 2018 waves of the Korean Welfare Panel Study, we examined the association between relative deprivation in income and suicide risk among South Koreans aged 25 or older. Relative deprivation is assessed with the Yitzhaki index, Deaton index, and income rank within the reference group, and suicide risk is measured as suicidal ideation and suicide planning or attempt in the preceding year. Adjusted for absolute income and other socioeconomic characteristics, the odds ratios of reporting suicidal ideation for each 10000 k KRW (8300 USD) increase in the Yitzhaki index were around 1.42 (95% CI: 1.08-1.87) to 1.72 (95% CI: 1.30-2.28). The estimated odds ratios were in the range of 1.70 (95% CI: 1.04-2.78) to 1.95 (95% CI: 1.26-3.02) for suicide planning or attempt. The association between relative deprivation in income and suicidal ideation was found significant only for men, not for women. The inferences were robust to various definitions of relative deprivation and reference group. Taken together, our findings suggest that relative deprivation in income is independently associated with higher odds of suicidal ideation and suicide planning or attempt over and above the effect of absolute income and material living conditions. Narrowing the income gap between individuals would be an effective policy response to a suicide epidemic in South Korea.