Psychosocial perspectives on suicidal thoughts: developmental trajectories and associated baseline factors among South Korean children

South Korea records the highest suicide mortality rate among OECD nations, with suicide constituting the primary cause of death for individuals aged 10–39 years. Despite extensive prevention efforts, limited research has examined the heterogeneous developmental patterns of suicidal thoughts during the critical elementary-to-middle school transition period. Understanding these developmental trajectories is essential for designing targeted, developmentally-informed intervention strategies.

This prospective longitudinal study utilized data from the Korea Children and Youth Panel Survey 2018, following 2607 students from 4th grade through 9th grade (2018–2023). Suicidal thoughts were assessed annually using a single-item measure. Latent class growth analysis was employed to identify distinct developmental trajectories, with comprehensive assessment of individual (gender, sleep duration, self-esteem, problematic smartphone use, academic performance), family (income, parental warmth, rejection, inconsistency), and school factors (peer relationships, teacher-student relationships) as baseline correlates of trajectory class membership.

Results revealed three distinct trajectory classes: low-stable (73.5%, n = 1915), moderate-increasing (19.2%, n = 501), and initially-high declining (7.3%, n = 191). The low-stable group maintained consistently minimal suicidal thoughts throughout the study period. The moderate-increasing group demonstrated persistently elevated levels with gradual increases over time.

The initially-high declining group began with extremely high levels but showed significant improvement, followed by a modest rebound. Self-esteem emerged as the strongest baseline correlate of trajectory membership, with higher self-esteem associated with greater likelihood of low-stable membership (OR = 2.187, 95% CI: 1.422–3.363) and lower likelihood of initially-high declining membership (OR = 0.149, 95% CI: 0.084–0.264) compared to the moderate-increasing trajectory. Gender differences were significant, with males showing higher likelihood of low-stable trajectory membership.

The identification of heterogeneous developmental patterns of suicidal thoughts provides important insights for suicide prevention among Korean children. The findings suggest that universal prevention approaches may be insufficient, highlighting the need for trajectory-specific interventions. Inha University, Incheon, Republic of Korea The author declares no competing interests.

This study was a secondary analysis of the Korean Children and Youth Panel Survey (KCYPS) 2018, a publicly available and de-identified longitudinal dataset. For the current secondary data analysis, the Institutional Review Board of Inha University determined that the study was exempt from ethical review (Exemption No. 250513-1 A; May 19, 2025). The original KCYPS 2018 data collection was conducted by the National Youth Policy Institute (NYPI), the institution responsible for the design and administration of the survey, and was approved by the Institutional Review Board of the National Youth Policy Institute (approval/protocol number: NYPI-202306-HR-041-01).