A preliminary prediction model for self-harm in adolescent inpatients with mental disorders: integrating individual and family factors

Background Self-harm is a major public health concern among adolescents, particularly those hospitalized with psychiatric disorders. Despite its clinical salience, risk stratification tools incorporating both individual-level and family-level factors remain limited. This study aimed to develop and preliminarily evaluate a prediction model for self-harm among adolescent inpatients with mental disorders. Methods This cross-sectional study included 123 adolescent inpatients (aged 12–17 years). Self-harm was defined as intentional self-injury or poisoning regardless of suicidal intent. Demographic, clinical, and familial variables were extracted from electronic medical records. Psychological assessments included the Children’s Depression Inventory (CDI), Parent-child Relationship Scale, Parents’ Perception of Uncertainty Scale (PPUS), parental Generalized Anxiety Disorder-7 (GAD-7), and parental Patient Health Questionnaire-9 (PHQ-9). The dataset was split into a training set (80%, n = 98) and a test set (20%, n = 25). Logistic regression with backward stepwise selection was used to construct a nomogram, with model performance assessed by the area under the curve and decision curve analysis. Results Four independent predictors of self-harm were identified: female sex (OR = 9.484, 95% CI: 2.736-32.868), higher CDI score (OR = 1.175 per 1-point increase, 95% CI: 1.058-1.305), higher parental PHQ-9 score (OR = 1.235 per 1-point increase, 95% CI: 1.064-1.433), and parental marital status (overall P = 0.001). The model showed good discrimination in the training set (AUC = 0.873) and acceptable performance in the testing set (AUC = 0.720). Decision curve analysis confirmed clinical utility across relevant threshold probabilities. Conclusion Female sex, higher depressive symptom severity, higher parental depressive symptoms, and parental marital status were associated with self-harm among hospitalized adolescents with mental disorders. The developed nomogram may serve as a preliminary screening aid for individualized risk stratification and may help clinicians identify patients requiring further assessment. External validation in larger, multicenter cohorts is needed before routine clinical use.