Psychosocial and Biological Factors Associated with Non-Suicidal Self-Injury in Chinese Child and Adolescent Inpatients with Major Depressive Disorder.

OBJECT: This study assessed the prevalence and associated psychosocial and biological factors of non-suicidal self-injury (NSSI) in Chinese child and adolescent inpatients diagnosed with major depressive disorder (MDD) by DSM-5 criteria.

METHODS

This cross-sectional study included 177 inpatients aged 10-16 years. Participants were assessed using the Childhood Trauma Questionnaire (CTQ), Hamilton Depression Scale (HAMD-24), Hamilton Anxiety Scale (HAMA), Shame Scale for Middle School Students (SS), and Mobile Phone Addiction Index (MPAI). Fasting blood levels of cortisol, thyroid hormones, and inflammatory markers were measured. Group comparisons (NSSI vs non-NSSI) used t-tests and chi-square tests, followed by binary logistic regression to identify independent associated factors of NSSI.

RESULTS

NSSI prevalence was 69.49%, with a higher proportion of females in the NSSI group. Compared to the non-NSSI patients, the NSSI group exhibited significantly higher scores on the HAMD-24, HAMA, shame, and MPAI scales, as well as higher cortisol and lower free triiodothyronine (FT3) levels. No significant differences were found in other biomarkers (Hypersensitive C-reactive protein, FT4, T3, T4, TSH, Adrenocorticotropic hormone). Regression analysis identified emotional neglect (OR = 1.223), depression severity (OR = 1.197), anxiety (OR = 1.186), shame (OR = 1.046), and cortisol (OR = 1.081) as significant factors associated with NSSI. Smartphone addiction and thyroid function-related indicators showed no significant association in the regression model.

CONCLUSION

NSSI is highly prevalent among child and adolescent inpatients with MDD and is associated with emotional neglect, depressive and anxiety symptoms, shame-proneness, and dysregulated cortisol levels. Smartphone addiction and other biological markers (Hypersensitive C-reactive protein, FT4, T3, T4, TSH, and Adrenocorticotropic hormone) showed no independent association with NSSI in the final model. These findings highlight the importance of integrated management of psychological and biological indicators in high-risk children and adolescents.