Background: The coronavirus disease 2019 (COVID-19) pandemic has negatively impacted many aspects of life. Measures for preventing the spread of COVID-19 (e.g., school lockdowns, remote and hybrid classes, group and outdoor activity restrictions, and social distancing in the classroom and meal time) could have led to adolescents to experience anxiety and depressive symptoms. Such mental health impacts could increase the risk of suicidal ideation in this population. Moreover, according to a report by the Organization for Economic Co-operation and Development, although the total number of suicide deaths in South Korea decreased in 2021, the suicide rate of those aged 10–29 years increased. One factor affecting the result is adolescent mental health by COVID-19. This study examines the mental health status of South Korean adolescents amid the prolonged COVID-19 pandemic, and identifies and analyzes predictors of suicidal ideation, suicide planning, and suicide attempts. Methods: The study used data from 54,948 adolescents who participated in the 2020 Korea Youth Risk Behavior Web-based Survey. Based on their responses to suicide-related questions, the sample was divided into a healthy group, suicide-ideation group, suicide-planning group, and suicide-attempt group. The descriptive statistics of these groups were then analyzed. An analysis of covariance, post-hoc tests, and multiple logistic regression analysis were performed on the four groups. Results: Overall, 6.9% of the participants reported suicidal ideation, 2.2% reported planning suicide, and 1.9% reported attempting suicide in the previous 12 months. Conclusions: During the prolonged COVID-19 pandemic, there is a strong need for various individualized programs that identify and intervene to support adolescents at risk of suicide by accurately assessing their mental health risk factors, such as stress, sadness and despair, loneliness, and generalized anxiety disorder. Accordingly, it is necessary to develop and distribute a mental health and well-being curriculum, strengthen suicide prevention programs and support services, expand mental health diagnostic tests, and school-based mental health programs.

This study aimed to identify the patient characteristics, comorbidities, risk factors, and means of the self-harm of patients who attempt self-harm in and outside of a hospital, and to determine the characteristics of death by suicide among survival and death patient groups in South Korea. This study used data from the Korean National Hospital Discharge In-depth Injury Survey conducted from 2007 to 2019. In total, 7192 outpatient participants and 43 inpatient participants performed self-harm. Frequency analysis, chi-square tests, Fisher’s exact test, and logistic regression analysis were performed using STATA, version 15.0 (StataCorp), and statistical significance was set at 5%. Thirty-one inpatients who performed self-harm survived, and 12 died. Among male inpatients, the older they were, the higher the rates of self-harm and mortality rates due to falls and poisoning if they had comorbidities and financial problems. In addition, the rate of self-harm attempts within a short period after hospitalization was high. Our evidence of the characteristics of patients who performed self-harm in the hospital and the influencing factors of self-harm can be used as primary data for predicting patients at a high risk of self-harm and for creating preventative policies to reduce the risk of self-harm among inpatients in South Korea.