Clinical characteristics and predictive modelling of intentional self-poisoning with prescribed medications among Chinese adolescents: a five-year retrospective study

INTRODUCTION: Intentional self-poisoning with prescribed medications (ISPPM) is an important form of self-harm and attempted suicide among adolescents. Analyses of clinical characteristics are vital for identifying recurrence risk factors and drug patterns for targeted interventions. METHODS: This was a retrospective analysis of adolescent ISPPM patients hospitalized in a Southwest China tertiary poisoning centre (January 2020–December 2024). Multivariate logistic regression was used to analyse the risk factors for recurrence, a generalized additive model (GAM) was used to analyse seasonal admission trends, and network analysis was used to identify combination patterns. RESULTS: A total of 462 patients were included (418 with a single admission and 44 with recurrent admissions). The patients (median age, 16 years) were predominantly female (80.5%). The number of inpatients with ISPPM showed an increasing trend annually. Patients with recurrent admissions (n = 44) were associated with significantly higher rates of previous psychiatric hospitalization (77.3% vs. 61.0%, P = 0.05) and antipsychotic drug use (61.4% vs. 41.1%, P = 0.016) but a lower incidence of impaired consciousness at admission (20.5% vs. 33.7%). Seasonal peaks occurred from April–June and September–December. The most common drug combination was antidepressants and antipsychotics (33.86%, n = 150). Multivariate analysis showed that antipsychotic drug use was associated with a higher risk of recurrence (OR = 3.12; P = 0.002), potentially reflecting greater clinical severity in this subgroup, and that impaired consciousness at admission was associated with a decrease in the ISPPM recurrence rate (OR = 0.29; P = 0.003). The preliminary recurrence prediction model had moderate discrimination (AUC = 0.717) and good calibration (Brier score = 0.081). CONCLUSIONS: The number of admissions for ISPPM has increased annually among adolescents, characterized by a female predominance, high depression incidence, high antipsychotic drug use, and obvious seasonal peaks. Antipsychotic drug use is associated with an increased risk of recurrence, likely serving as a marker of disease severity rather than a direct cause. CLINICAL TRIAL NUMBER: Not applicable.