Purpose of the Review <p>Despite the growing interest in non-suicidal self-injury (NSSI) research over the past decades, there is no comprehensive synthesis of findings on whether this behaviour should be considered an addiction. This study carries out a systematic review of theoretical and experimental studies to evaluate the empirical evidence supporting the addictive nature of NSSI.</p> Recent Findings <p>In accordance with PRISMA guidelines, 36 studies were selected from a search across PubMed, Scopus, and Web of Science, covering publications from 2000 to November 2024. This review suggests that the subjective experiences of individuals who self-injure, the DSM-5 diagnostic criteria, and some relevant assessment instruments, all point to there being addictive characteristics in NSSI. These characteristics include compelling urges, altered control, and behaviour intensification. Neurobiological findings, particularly those involving the endocannabinoid and opioid systems, support the addictive-like nature, with tolerance being a key mediating factor that leads to the NSSI cyclical structure. Additionally, findings related to brain activity, connectivity, and gene expression also hint at similarities between NSSI and addictive disorders, suggesting some shared mechanisms.</p> Summary <p>Existing research on NSSI emphasises its potentially addictive nature. The subjective experiences of those who self-injure together with diagnostic criteria and neurobiological findings, collectively support the conceptualization of NSSI from an addictive model. While further studies are needed to fully understand the underlying mechanisms and factors contributing to addictive patterns in NSSI, this perspective has significant implications for the prevention and treatment of NSSI.</p>