Expert Commentary

Solitary confinement in prisons: Key data and research findings

2014 study in the American Journal of Public Health showing a "strong association" between solitary confinement and acts of self-harm.

America’s prison population is the largest in the world, with 2.2 million people incarcerated across federal, state and local levels — representing a four-fold increase since 1973. A 2014 U.S. National Research Council report notes that in 2012 roughly one quarter of the world’s entire prison population was housed in the United States; about 1 in every 100 American adults are in prison.

One correctional facility practice that has come under scrutiny in recent years is the separation of prisoners into special quarters for the purposes of safety or additional punishment. Known variously as “solitary confinement,” “isolation,” “segregation,” “special management” or “restricted housing,” the practice frequently involves putting prisoners in small, confined spaces for months, even years. Curbing this practice has become a central focus of prison reform and has spurred the “Stop Solitary” movement, which argues that it constitutes inhumane treatment and makes things considerably worse for the sizable mentally ill population now in U.S. prisons. Meanwhile, journalists continue to investigate and make more visible issues relating to the psychology of isolation, the day-to-day realities of extreme confinement and activism by prisoners. In January 2016, President Obama announced that he was adopting a list of recommendations made by the U.S. Department of Justice aimed at limiting the use of restrictive housing in federal prisons. The changes called for, among other things, ending solitary confinement for juveniles and increasing the number of hours that inmates who have been placed in solitary confinement spend outside their cells.

The president’s action came after the August 2015 release of a Yale Law School research paper titled “Time-In-Cell: The ASCA-Liman 2014 National Survey of Administrative Segregation in Prison,” which offers a close look at the use and conditions of restrictive housing. The report focuses on 31,500 male prisoners, many of whom spent at least 23 hours a day in small cells ranging in size from 45 to 128 square feet. That report built upon an earlier, 2013 Yale Law School paper, “Administrative Segregation, Degrees of Isolation, and Incarceration: A National Overview of State and Federal Correctional Policies,” which had noted that “correctional officials believe that protection of inmates and staff is enhanced through long-term separation policies,” though given available data, it remains unclear “whether the policies are implemented as written, achieve the goals for which they are crafted, and at what costs.” The Government Accounting Office (GAO) concurred and issued a 2013 report on the federal Bureau of Prisons (BOP), stating, at the time, that the “BOP has not assessed the impact of segregated housing on institutional safety or the impacts of long-term segregation on inmates.”

At the time of the 2013 GAO report, the federal system confined about 7.1 percent of its 217,000 prisoners in solitary units for roughly 23 hours a day. Within the federal system, there are different types and levels of confinement, referred to as Special Housing Units (SHU), Special Management Units (SMU) and Administrative Maximum (ADX). Increasing use of solitary confinement had taken place across the federal system, the report notes: “From fiscal year 2008 through February 2013, the total inmate population in segregated housing units increased approximately 17 percent — from 10,659 to 12,460 inmates. By comparison, the total inmate population in BOP facilities increased by about 6 percent during this period.” Housing prisoners this way is more expensive because it is more staff-intensive. While costs per inmate at federal facilities are around $57 a day for a medium-security and $69 for a high-security prison, those costs rise to $78 and $93 a day, respectively, for prisoners in segregated housing units. For administrative maximum units, costs can rise to $216 a day per inmate.

A 2012 report from the Colorado Department of Corrections found that prisoners spent a mean of 19.5 months in isolation. Some were sent there because of infractions such as assaults on staff or other prisoners, while many others were sent because of gang or drug-related activity.

A 2014 study published in the American Journal of Public Health, “Solitary Confinement and Risk of Self-Harm Among Jail Inmates,” analyzes the medical records of more than 134,000 prisoners, with a combined 245,000 incarcerations, over the period 2010-2013. The researchers are doctors and mental health experts affiliated with the New York City Department of Health and Mental Hygiene. Among the population of prisoners studied, about 56.1 percent were non-Hispanic Black, 31.6 percent were Hispanic and 8.4 percent were non-Hispanic white. This study provides unique insight into city and municipal jails, where inmates frequently receive shorter stays in solitary confinement than they sometimes see in state and federal systems.

The study’s findings include:

  • Solitary confinement was “strongly associated” with increased risk of self-harm. “Inmates ever assigned to solitary confinement were 3.2 times as likely to commit an act of self-harm per 1,000 days at some time during their incarceration as those never assigned to solitary…. These inmates assigned to solitary were 2.1 times as likely to commit acts of self-harm during the days that they were actually in solitary confinement and 6.6 times as likely to commit acts of self-harm during the days that they were not in solitary confinement, relative to inmates never assigned to solitary confinement.”
  • After controlling for length of jail stay, serious mental illness, age and race, the researchers determined that prisoners “punished by solitary confinement were approximately 6.9 times as likely to commit acts of self-harm.”
  • Of all the incarcerations analyzed, 4 percent involved inmates who were diagnosed with serious mental illness. Overall, 7.3 percent of incarcerations involved solitary confinement.
  • “In 1,303 of these incarcerations there were 2,182 acts of self-harm; in 89 incarcerations there were 103 acts of potentially fatal self-harm. The most common methods of self-harm were laceration (34 percent), ligature (28 percent), swallowing a foreign body (15 percent), and overdose (14 percent).”

The researchers note that inmates “often confide that their self-harm acts are used as a means to avoid the rigors of solitary confinement” and that “many inmates report to us that they have and will continue to do anything to escape these settings.” These “manipulative” acts complicate interpretations of the data. Further, they write, an “additional layer of complexity is that patients placed in solitary confinement, especially those with mental illness, will often earn new infractions, resulting in even more solitary time. In the most extreme type of example, a patient held in solitary confinement may break off a sprinkler head, use that metal to slash themselves, and then earn not only a new infraction and more solitary confinement time, but also a new criminal charge for destruction of government property.”

Related research: A 2016 study published in Psychiatry Research examines the link between self-inflicted pain and boredom. The 2014 National Research Council report, “The Growth of Incarceration in the United States: Exploring Causes and Consequences” — which is authored by some of the nation’s leading criminal justice scholars —  includes a chapter, “The Experience of Imprisonment,” that reviews the research on solitary confinement more generally and makes some general recommendations. It concludes:

In many ways, the use of long-term segregation needs to be reviewed. It can create or exacerbate serious psychological change in some inmates and make it difficult for them to return to the general population of a prison or to the community outside prison. Although certain highly disruptive inmates may at times need to be segregated from others, use of this practice is best minimized, and accompanied by specific criteria for placement and regular meaningful reviews for those that are thus confined. Long-term segregation is not an appropriate setting for seriously mentally ill inmates. In all cases, it is important to ensure that those prisoners who are confined in segregation are monitored closely and effectively for any sign of psychological deterioration.

The 2008 paper “The Psychological Effects of Solitary Confinement on Prisoners in Supermax Units: Reviewing what We Know and Recommending What Should Change” and the 2010 paper “Solitary Confinement and Mental Illness in U.S. Prisons: A Challenge for Medical Ethics” also provide vital background. Further, the American Civil Liberties Union, which advocates against the use of solitary confinement, has issued a 2014 report about the experiences of women inmates.

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