Understanding Comorbidity Between Non-Suicidal Self-Injury and Depressive Symptoms in a Clinical Sample of Adolescents: A Network Analysis

Shan Niu,1,* Xiaoxiao Yin,1,* Bing Pan,2 Haotian Chen,1 Chunxiao Dai,3 Chunnan Tong,4 Fang Chen,2 Xiuqin Feng1 1Nursing Department, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China; 2Department of Psychiatry, Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China; 3Department of Clinical Psychology, Affiliated Hangzhou First People’s Hospital Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China; 4Department of Psychiatry, The Second Hospital of Jinhua, Jinhua, Zhejiang, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiuqin FengNursing Department, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, Zhejiang, People’s Republic of China, Email fengxiuqin@zju.edu.cnBackground: Non-suicidal self-injury (NSSI) and depression often co-occur among adolescents with more severe clinical symptoms. This study examined the network structures of NSSI and depressive symptoms in adolescents.Methods: Participants were recruited in the psychiatric outpatient clinics of three tertiary hospitals between April 10 and July 10, 2023. All participants been already found with self-injury behaviors in outpatient when enrolled. NSSI diagnostic criteria and Patient Health Questionnaire-9 (PHQ-9) were utilized to collect NSSI and depressive symptoms separately. We performed a network analysis to visualize the correlation between each symptom and to identify core and bridging symptoms in comorbidities.Results: A total of 248 patients were enrolled in the study, with a mean age of 15.48 (SD = 1.62). Based on the PHQ-9 scores and grades, our results showed that the incidence of depression in adolescents with non-suicidal self-injury behavior was relatively high (N=235, 94.76%), with the majority having severe depression. The network analysis revealed that nodes D-6 “feeling bad, failing or letting yourself or your family down”, D-1 “little interest or pleasure” and D-4 “feeling tired” were the most vital and most central symptoms. The most crucial bridging symptom is the node NSSI-8 “frequent thinking about self-injury”, which connects the NSSI to the depression comorbid network.Conclusion: This study offers a significant symptom-level conceptualization of the association between NSSI and depressive symptoms in a clinical sample of adolescents, which not only enhances our understanding of the comorbid but also identifies potential treatment targets to prevent and treat comorbidity between adolescent NSSI and depression.Keywords: non-suicidal self-injury, depression, comorbidity network, bridge symptoms, network analysis