Being held in restrictive housing can result in significant negative effects.

Over 150 years of research in psychiatry, neuroscience, epidemiology, and anthropology has documented the harmful effects of restrictive housing on the health and well-being of incarcerated people.^[]Craig Haney and Mona Lynch, “Regulating Prisons of the Future: A Psychological Analysis of Supermax and Solitary Confinement,” New York University Review of Law and Social Change 23 (1997), 477-570; Stuart Grassian, “Psychiatric Effects of Solitary Confinement,” Washington University Journal of Law & Policy 22 (2006), 325; Craig Haney, “Mental Health Issues in Long-Term Solitary and ‘Supermax’ Confinement,” Crime & Delinquency 49, no. 1 (2003), 124-156; Peter Scharff Smith, “The Effects of Solitary Confinement on Prison Inmates: A Brief History and Review of the Literature,” Crime and Justice 34, no. 1 (2006), 441-528; Stuart Grassian and Nancy Friedman, “Effects of Sensory Deprivation in Psychiatric Seclusion and Solitary Confinement,” International Journal of Law and Psychiatry 8, no. 1 (1986), 49-65; Paul Gendreau, N.L. Freedman, G.J. Wilde, and G.D. Scott, “Changes in EEG Alpha Frequency and Evoked Response Latency During Solitary Confinement,” Journal of Abnormal Psychology 79, no. 1 (1972), 54; Fatos Kaba et al., “Solitary Confinement and Risk of Self-Harm Among Jail Inmates,” American Journal of Public Health 104, no. 3 (2014), 442-447; and Lars Moller et al., eds., Health in Prisons: A WHO Guide to the Essentials in Prison Health (Copenhagen: World Health Organization, 2007), 36.  This evidence confirms what is perhaps understood intuitively: the practice can result in physical and psychological damage that can persist even after release, making the transition to life in a prison’s general population or the community considerably more difficult. 

Research provides no conclusive evidence that restrictive housing improves safety.

Keeping people in restrictive housing is extremely resource-intensive, and research provides no conclusive evidence that it makes facilities or communities safer.^[]Daniel P. Mears and William D. Bales, “Supermax Incarceration and Recidivism,” Criminology 47, no. 4 (2009), 1135; and Natasha Frost and Carlos E. Monteiro, “Administrative Segregation in U.S. Prisons” (Washington, DC: U.S. Department of Justice, National Institute of Justice, March 2016, NCJ 249749R.M), citing Ryan Labrecque, “The Effect of Solitary Confinement on Institutional Misconduct: A Longitudinal Evaluation” (PhD diss., University of Cincinnati, 2015).  Attention has also turned toward the impact restrictive housing has on staff. Studies have demonstrated that corrections officers face stressors that can negatively affect their mental and physical health and family relationships.^[]Michael D. Denhof, Caterina G. Spinaris, and Gregory R. Morton, Occupational Stressors in Corrections Organizations: Types, Effects and Solutions (Washington, DC: U.S. Department of Justice, National Institute of Corrections, 2014, NIC 028299.  Researchers have recently started to explore whether working in the unique conditions found in restrictive housing units is associated with markers of safety and well-being, such as depression, stress, trauma, injury, or sick leave.^[]Lionel Smith, “Why We’re Studying the Causes and Consequences of Solitary Confinement,” Think Justice Blog, Vera Institute of Justice, January 26, 2017.