Characteristics of Self-Harm in an Emergency Situation Among Youth: A Longitudinal Five- Year Cohort Study.

Self-harm is a growing phenomenon among young people. This study examined self-harm rates in youths over five years, before and after the onset of the COVID-19 pandemic. Additionally, we explored risk factors influencing self-harm repetition. We conducted a retrospective analysis of people under 25 years who presented with self-harm at an emergency department in Seville, Spain, from January 1st 2018 to December 31st 2022. Participants were identified through hospital records. We used Joinpoint regression analysis to assess changes in trends and compared demographic and clinical variables between pre- and post-pandemic periods. Cox regression analysis was employed to identify predictors of repeated self-harm. The study included of 726 individuals, with 282 (38.84%) and 444 (61.16%) first-time self-harm cases before and after the COVID-19 pandemic onset, respectively. A significant increase in self-harm rates was observed from December 2020 to March 2021. Post-pandemic, there was an over-representation of 10-14-year-olds, increased substance use rates, and a higher proportion of suicide attempts compared to non-suicidal self-injuries. Affective disorders, personality disorders, lifetime psychiatric history, and previous non-suicidal self-injuries were associated with higher rates of recurring self-harm episodes. Self-harm among young people increased one year after the initial COVID-19 outbreak. Post-pandemic first-time self-harm cases exhibited higher rates of substance use and tended to engage in suicide attempts, particularly among 10-14-year-olds. Recurrence was associated with psychiatric diagnosis, psychiatric history and non-suicidal self-harm history.