Chenyu Zhang,1,2,* Yalan Li,1,* Wo Wang,1 Zhenghao Jiang,1 Chuan Liu,1 Yiting Kong,2 Daqi Li,1 Liuyi Ran,1 Li Kuang1,2 

1Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, 401331, People’s Republic of China; 2Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Liuyi Ran; Li Kuang, Mental Health Center, University-Town Hospital of Chongqing Medical University, Shapingba District, Chongqing, 401331, People’s Republic of China, Tel/Fax +86-023-65714061, Email ranliuyi@163.com; kuangli0308@163.com

Purpose: The aim of our study was to explore the relation between serum levels of non-enzymatic antioxidants, thyroid function with the risk of non-suicidal self-injury (NSSI) in depressed adolescents.
Patients and Methods: We retrospected the electronic records of 454 hospitalized patients aged 13– 17 years old with a diagnosis of major depressive disorder (239 patients with NSSI and 215 subjects without NSSI), and collected their demographic and clinical information, including serum levels of total bilirubin (Tbil), uric acid (UA), free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH).
Results: The incidence of NSSI was 52.6% among depressed adolescents aged 13– 17, 57.1% in female and 38.5% in male. After using the propensity scoring method to exclude the influence of age between the two groups, it was found that patients with NSSI showed lower levels of Tbil (P=0.046) and UA (P=0.015) compared with those without NSSI. Logistic regression results showed that serum UA was associated with NSSI behavior in female patients (OR=0.995, 95% CI: 0.991– 0.999, P=0.014), and TSH was associated with NSSI in male participants (OR=0.499, 95% CI: 0.267– 0.932, P=0.029).
Conclusion: Female and male may have different pathological mechanisms of NSSI. NSSI is more likely to be related to antioxidant reaction in female adolescent patients, while more likely to be related to thyroid function in male depressed adolescent patients.

Keywords: antioxidant system, depressed adolescents, incidence, non-suicidal self-injury, thyroid function