Investigation of the associations between non-suicidal self-injury and neurotrophic factor levels and resilience in children and adolescents

Introduction and Objective: Non-suicidal self-injury (NSSI) is a clinical condition characterized by the deliberate damage of body tissue without an intent to die. The interplay between biological processes involved in the emergence and maintenance of NSSI and protective psychosocial factors has not yet been sufficiently elucidated. Neurotrophic factors, which play roles in nervous system development, neuroplasticity, and the stress response, may be associated with NSSI; resilience is thought to be protective against self-injurious behavior in children and adolescents. This study aimed to compare neurotrophic factor levels and resilience in children and adolescents with NSSI and healthy controls, and to examine the associations of these variables with the clinical characteristics of NSSI. Materials and Methods: In this cross-sectional case–control study, 88 children and adolescents aged 10–18 years who reported more than five episodes of NSSI in the past year and 82 healthy children and adolescents without any psychiatric diagnosis were included after obtaining written informed consent. All participants were administered a sociodemographic data form and the Child and Youth Resilience Measure-12 (CYRM-12), psychiatric diagnoses were assessed using the K-SADS-PL, and NSSI characteristics were evaluated using the Inventory of Statements About Self-injury (ISAS). Serum levels of BDNF, NGF, CDNF, GDNF, and NT-3 were measured using the ELISA method in blood samples obtained from residual routine laboratory tests. Results: The median CYRM-12 score was 35 (30–41) in the NSSI group and 52 (45–56) in the control group, indicating significantly lower resilience levels in the NSSI group (p<0.001). Serum levels of neurotrophic factors were significantly higher in adolescents with NSSI compared to controls, and the group differences for BDNF, CDNF, GDNF, and NT-3 remained significant after controlling for age, sex, body mass index, and household income. A negative association was found between the number of NSSI methods used and resilience within the NSSI group, whereas no significant association was observed between the number of methods and neurotrophic factors. In the entire sample, a weak inverse correlation was identified between NGF levels and resilience. Hierarchical logistic regression analysis revealed that NGF showed the strongest association with membership in the NSSI group, while NT-3 was inversely associated. Discussion: The association between low resilience and the number of methods used in NSSI among children and adolescents suggests that interventions aimed at enhancing resilience may play a role in the prevention and treatment of NSSI. When neurotrophic factors were evaluated together, the finding that NGF showed the most pronounced association with NSSI and that NT-3 was inversely associated with NSSI may be noteworthy for understanding the neurobiological dimension of NSSI. Longitudinal studies that take factors such as comorbidities and medication use into account are needed. Keywords: Non-suicidal self-injury, neurotrophic factors, BDNF, NGF, CDNF, GDNF, NT-3, resilience, adolescent