Intrinsic Links Between Non-Suicidal Self-Injury and Sleep Quality and Cytokines: A Network Analysis Based on Chinese Adolescents with Depressive Disorders

Yang Zhang,1,* Xingbo Suo,2,* Xinqi Wang,1,* Jingjing Xu,1 Wangwang Xu,1 Liangke Pan,3 Jin Gao1 1Department of Clinical Psychology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, Shandong, People’s Republic of China; 2Department of Psychosomatic Medicine, The 1st Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 3Qingdao No.9 high School (Qingdao Foreign Language School), Qingdao, Shandong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jin Gao, Department of Clinical Psychology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, Shandong, People’s Republic of China, Email [email protected]: Non-suicidal self-injury (NSSI) in adolescents has a complex etiology and a wide range of negative consequences. This study aimed to assess the interactions between NSSI and sleep quality and cytokines and explore the association of these factors with cognitive flexibility.Methods: A cross-sectional survey was conducted from January 2022 to September 2024 in Qingdao, China. Adolescent Non-Suicidal Self-Injury Assessment Questionnaire, Pittsburgh Sleep Quality Index, and Wisconsin Card Sorting Test 128 card version were used to assess the NSSI, sleep quality, and cognitive flexibility. Levels of 12 serum cytokines were measured. Network analysis was performed by R software (version 4.4.1) to identify the central nodes and bridging symptoms of the network and all nodes’ association with cognitive flexibility.Results: A total of 337 adolescents with depressive disorders were included in the study. In the NSSI-Sleep Quality-Cytokines Network “Intentional scratches”, “IL-12p70”, and “Intentionally hitting oneself with fists or harder objects” were central nodes in the network. Furthermore, sleep-related variables such as “Sleep disturbance” and “Sleep duration” were identified as bridge symptoms. No direct association between NSSI and cognitive flexibility was observed.Limitations: The cross-sectional design, reliance on self-reported data, and restricted geographic sample limit the ability to establish causal relationships and generalize the findings.Conclusion: IL-12p70 plays a significant role in the development of NSSI among adolescents with depressive disorders. Sleep problems facilitate the interaction between NSSI and cytokines. Cognitive flexibility may be related to NSSI through indirect pathways.Keywords: non-suicidal self-injury, sleep quality, cytokine, cognitive flexibility, network analysis