Suicide trends by sex, age, and method in South Korea, 1983–2022: Joinpoint regression and age–period–cohort analyses

Background: South Korea has had among the highest suicide rates in high-income countries over the past two decades. We investigated long-term suicide trends by sex, age, and method and examined age, period, and cohort effects on suicide in South Korea in 1983–2022. Methods: We extracted national mortality data for suicide among individuals aged 15+ years and calculated suicide rates by sex, age (15–24, 25–44, 45–64, and 65+), and method (hanging, pesticide poisoning, jumping, carbon monoxide [CO] poisoning, drowning, and others). Joinpoint regression was used to examine trends in suicide. Age-period-cohort analysis was performed to decompose the age, period, and birth cohort effects on suicide rates. Results: Suicide rates rose markedly from the early 1990s, peaking around 2010, particularly among individuals aged 65+. Rates among males declined from the early 2010s, but rates among females showed no recent reduction. Suicide in young females aged 15–24 increased by 12.2% annually in 2015–2022. Hanging remained the most common method for most sex/age groups. Pesticide poisoning suicides showed a sustained reduction following the 2011–2012 paraquat ban. Jumping became prevalent among youths aged 15–24 after 2015–2016. CO poisoning suicide increased markedly after 2008, especially among males aged 25–64 years, while its rate stabilized after 2014. Females born after the early 1990s exhibited increased suicide risk. Conclusions: The recent rise in suicide among young females is an emerging public health issue. High suicide rates of CO poisoning among middle-aged males remain a concern. Future research and prevention need to identify and address factors underlying these trends.