Internet Addiction and Non-Suicidal Self-Injury in Adolescents with Major Depressive Disorder: The Sequential Mediating Roles of Insomnia and Depressive Symptoms
Year: 2026
Type: preprint
Study design: Observational Study
Abstract: Background Internet addiction (IA) frequently co-occurs with major depressive disorder (MDD) and was associated with non-suicidal self-injury (NSSI). However, the underlying psychological mechanisms linking IA to NSSI, particularly through the roles of depressive symptoms and insomnia, remain inadequately explored. This study aimed to investigate whether depressive symptoms and insomnia mediate this relationship. Methods This cross-sectional study included 166 adolescent MDD patients and 101 matched healthy controls. Participants completed measures assessing IA, depressive symptoms, insomnia severity, NSSI frequency, and NSSI functions (emotion regulation-ERG, attention seeking-ASG, social avoidance-SAE). Mediation analysis was employed to examine direct and indirect pathways between IA, depressive symptoms, insomnia, and NSSI outcomes. Results The prevalence of IA was significantly higher in the MDD group than in controls (47.6% vs. 17.8%, P < 0.001). MDD patients with IA demonstrated more severe depressive symptoms, insomnia, and NSSI (all P < 0.05). Linear regression showed that while IA initially predicted all NSSI outcomes, these associations became non-significant after controlling for depressive symptoms and insomnia. Mediation analysis revealed that IA had direct effects on NSSI functions (ERG: β = 0.200, P = 0.005; ASG: β = 0.176, P = 0.025; SAE: β = 0.181, P = 0.027) but not on NSSI frequency. Crucially, significant sequential mediation was observed, with IA influencing NSSI through insomnia and subsequently through depressive symptoms (DSHI: β = 0.058, P = 0.005; ERG: β = 0.059, P = 0.014; ASG: β = 0.047, P = 0.032; SAE: β = 0.056, P = 0.018). Conclusion The association between IA and NSSI in MDD adolescents is primarily explained by a sequential worsening of insomnia and then depressive symptoms, highlighting these as critical intervention targets to reduce self-injury risk. Trial registration: Chinese Clinical Trial Registry (ChiCTR), Affiliated Chaohu Hospital of Anhui Medical University. Registration number ChiCTR2100041826, approval date: 6 January 2021.
Source: Research Square
Language: English
Subfield: Clinical Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
Award: G1293410295
OpenAlex ID: W7222902015