The Concentration of Self-Injurious Behavior in Prisons: Institutional Hotspots and Serial Self Injury

Self-injurious behavior (SIB) poses persistent clinical and operational challenges in prisons. Yet, its institutional distribution remains under-examined. Using administrative records from a large state prison system, this study examines SIB concentration and seriality from FY 2019–2020 through FY 2023–2024. Across the period, 10,752 SIB events involved 4,828 individuals. In FY 2023–2024, 2,291 events involved 1,349 individuals, a rate of 30.1 per 1,000 inmates. The top 20 facilities accounted for 68.2% of events and 59.7% of involved individuals, demonstrating substantial institutional concentration. Rather than treating SIB as evenly distributed across prisons, agencies should consider using concentration and seriality metrics to identify institutional hotspots and prioritize targeted clinical and operational interventions.