Effectiveness of a Phenomenology-Based Intervention Protocol on Self-Harming Behaviors in Adolescent Girls with a History of Non-Suicidal Self-Injury

Abstract

This study aimed to examine the effectiveness of a phenomenology-based intervention protocol in reducing self-harming behaviors among adolescent girls with a history of non-suicidal self-injury. An exploratory sequential mixed-methods design was applied. In the qualitative phase, semi-structured interviews with 30 adolescent girls with a history of self-injury were conducted and analyzed using interpretative phenomenological analysis. Based on these findings, an 11-session, 90-minute group intervention protocol was developed. In the quantitative phase, a quasi-experimental pre-test/post-test design with a control group was employed. Thirty participants were purposively selected from middle school girls in District 12 of Tehran and randomly assigned to experimental and control groups (15 each). The Self-Harm Inventory (SHI) was used for data collection, and data were analyzed using multivariate analysis of covariance (MANCOVA). Results of covariance analysis indicated a significant reduction in self-harming behaviors in the experimental group (F=57.668, p=0.001, η²=0.706), while no significant changes were observed in the control group. This demonstrated the positive impact of the phenomenology-based protocol in decreasing self-harming behaviors. The designed intervention protocol effectively reduced self-harming behaviors in adolescent girls with a history of non-suicidal self-injury. This approach can serve as a novel and practical tool for schools and counseling centers to promote adolescent mental health and prevent high-risk behaviors.