There is a vast library of research around solitary confinement and its effects. In this article I will summarise and note important research and what it says about solitary confinement. In my next article I will go through the research of the last 5 years.
There have been many decades of research into the effects of solitary confinement which finds a host of problematic symptoms such as anxiety, rage, paranoia, hallucinations and self injury. Additionally, there have been studies about how solitary confinement is reacted to including negative affect and attitude, insomnia, withdrawal, cognitive dysfunction, loss of control, irritability and aggression, lethargy, depression and suicidal thoughts and behaviour. A correlation had been found between self injury and suicide and solitary confinement and there have also been studies which correlate worsening physical and mental health and violence with solitary confinement.
“To summarize, there is not a single published study of solitary or supermax-like confinement in which nonvoluntary confinement lasting for longer than 10 days, where participants were unable to terminate their isolation at will, that failed to result in negative psychological effects. The damaging effects ranged in severity and included such clinically significant symptoms as hypertension, uncontrollable anger, hallucinations, emotional breakdowns, chronic depression, and suicidal thoughts and behavior.” - Haney (2003).
Adverse effects of solitary confinement
Much of the research on solitary confinement has produced results of adverse effects on prisoners. Prisoners in solitary confinement have a higher rate of psychological illness than the general population. There were some Danish studies published in the beginning of the 1980s by Jensen and colleagues (1980) and Jorgensen (1981). These studies used case study data from 46 prisoners on remand and in solitary confinement. It was claimed that those in solitary confinement showed evidence of an acute and chronic isolation illness. Prisoners showed many symptoms including difficulties with memory and concentration, insomnia, lack of emotional control, anxiety, paranoid and hallucinations. These symptoms linger after prisoners are removed from solitary confinement.
A study in Zurich by Volkart, Rothenfluth, et al. (1983) found 76% of male patients in a psychiatric clinic came from solitary confinement and that prisoners who were on remand and put into solitary confinement were more likely to be hospitalised for psychiatric problems than those in the general population. In another study in 1983 by many of the same authors found prisoners in solitary confinement had more psychological problems than the control group. Finally, Grassian (1983) studied 14 inmates in a prison in Massachusetts who were the plaintiffs in a legal case. Grassian found a collection of severe symptoms in the sample which he argued constituted a psychiatric disorder. This study did have a small sample size, no control group and selection bias, but Grassian’s qualitative analysis was very good.
Also in 1983 Jackson studied solitary confinement in Canada, and seven inmates were interviewed who were plaintiffs in a court case. They argued solitary confinement caused severe physical and psychological effects and won the case and conditions were deemed to be cruel and unusual in the unit they were in in British Columbia Penitentiary.
Foster et al. (1987) carried out a South African study on solitary confinement. The authors found that those in solitary had anxiety and fears of going crazy. The authors believe solitary confinement is torture. Brodsky and Scogin (1988) looked at the effects of protective custody in prisons across America over three studies. The first and second study found a high rate of psychiatric symptoms including nervousness (84% of those in solitary confinement), hallucinations (42%) and suicidal thoughts and depression (77%) in the first study and physical symptoms (79%), anxiety (45%) and depression (36%) in the second study. The researchers could not assign cause but the third study where inmates in protective custody were put in cells with another person with access to programs and more space did not show these symptoms. The authors conclude that protective custody has the potential to be harmful. This research was supported by Korn’s 1988 studies in which he studied the effects of solitary confinement in prisons in Kentucky. He interviewed staff and five inmates who were women. Korn found a range of psychological symptoms including depression, hallucinations, anxiety and apathy.
In 1992, Toch carried out interviews with inmates in state prisons in New York, some of whom were in solitary confinement. Toch argues solitary confinement causes psychological damage including symptoms of anxiety, rage and a loss of control.
In the early 1990s there were a handful of studies done in some Scandinavian countries. In 1993, a Norwegian study by Gamman of remand prisoners in solitary confinement found many health problems in prisoners in isolation after four weeks including, depression, anxiety, muscle pains, stomach pain and lack of ability to concentrate. A follow up study in 1995 by the same author found prisoners in solitary confinement had many more health problems than those in the control group; including insomnia, problems concentrating, anxiety and depression.
A 1994 Danish study by Andersen and colleagues found prisoners in solitary had more psychiatric issues than the control group. However, this study involved extensive contact between doctors, researchers and those in solitary which means that the prisoners could not be classified as being in solitary confinement for the whole period of the study. This could have impacted the differences between the two groups. In the second half of the study they found a prisoner in solitary confinement for four weeks is 20 times more likely to be put in hospital for psychiatric reasons than those in the general population. A follow up of this study in 1997 by Andersen and colleagues involved reports from the participants of the 1994 study. It found that prisoners who were in isolation during their period of remand experienced more strain than those kept with others when on remand. A higher proportion of the sample reported psychological reactions to imprisonment if they were in isolation when on remand than those in the general population.
Haney assessed California’s Pelican Bay Secure Housing Unit in the early 1990s. Haney found severe health problems were present in a large number of the inmates, e.g. 91% experience anxiety, 70% felt they were almost at the point of having a nervous breakdown and 77% experienced chronic depression. Some had trouble concentrating or remembering things (84%), had difficult thinking (84%), had major mood swings (71%) and experienced hallucinations (41%). Inmates with psychological illnesses suffer from more psychological distress than those without. Evidence suggests this is 10-20% of inmates have a psychological illness but it is much higher in supermax. Treatment cannot really be offered in supermax and staff are ill equipped to deal with psychological distress. The mentally ill are punished for their behaviour instead of giving them treatment.
The Human Rights Watch Cold Storage report looked at research in 1995, 1996 and 1997 in Indiana supermax prisons. Brief conversations with 40 inmates and more in depth interviews with 10 inmates occurred in 1995 and 1996. The research found the majority of prisoners in supermax had a psychiatric condition. The researchers could not say segregation causes mental illness but found that mental illness is made worse by being in segregation.
In 1999, Martel interviewed 12 women who were put in solitary confinement in Canada. Martel concluded that isolation has debilitating effects on inmates’ psychological state and the many of the women feared going crazy. Clare et al. (2001) studied English Close Supervision Centres and gave psychiatric tests to prisoners and then 23 of these inmates were interviewed. It was found that prisoners in segregation had a high rate of mental illness.
Stang et al. (2003) in a Norwegian study of solitary confinement in Oslo Prison, studied 30 inmates in isolation who were compared to a control group not in isolation. It was found that there were severe psychiatric symptoms in the solitary confinement group such as depression and hallucinations.
Smith (2003) in a study of Danish solitary confinement effects from archival records from the 19th century, found a third of the 300 inmates included in the study experienced psychological effects from being in solitary confinement. There was no control and mental illness in the past does not have the same definition as it does now, but it was an interesting study.
Rhodes (2004) did an anthropological study of a supermax penitentiary in Washington State. Rhodes found psychological effects such as hallucination, anger, paranoid, depression and delusions.
Mears & Bales (2009) looked at data from the Florida Department of Corrections to see whether being placed in supermax decreases or increases recidivism. They found there was no reduction in recidivism by supermax prisoners. This contradicts the specific deterrence it is meant to have on prisoners. Additionally, supermax incarceration can slightly increase violent reoffending.
Kaba and colleagues (2014) studied the effect of solitary confinement on self harm. They found the risk of self harm increased for those in solitary confinement. Prisoners who were sent to solitary confinement were 3.2 times more likely to self harm than those who were not sent to solitary confinement. This is further broken down by self harm while being in solitary confinement and not. Inmates were 2.1 times more likely to self harm in solitary confinement and 6.6 times more likely to self harm out of solitary confinement. It was found that solitary confinement, having a serious mental illness, the length of prison sentence and race were associated with more self harm. It was also seen that being in solitary confinement had a large effect on self harm, even without a serious mental illness or taking into account the age of the prisoner.
Hagen and colleagues (2018) researched the relationship between PTSD and solitary confinement. They found those who had been placed in solitary confinement were more likely to screen positive for PTSD symptoms. Severe mental illness and solitary confinement history were significantly related to PTSD symptoms.
A meta analysis done on research before 2020 included 12 studies on solitary confinement that studied 194,078 inmates. Results from the studies showed an increased recidivism rate for those who had been in solitary confinement. This increase was found across studies from one year post release to seven years post release. Increases in recidivism were found across studies no matter what type of recidivism was studied. Additionally, inmates who were in solitary confinement had increased recidivism beyond their risk level as recorded when first put in prison. There was also an effect where the length of solitary confinement increased the odds of recidivism. Additionally those who were put in administrative segregation were found to have worse rates of recidivism when compared to other types of solitary confinement. This may be because of the length of this type of solitary confinement, which can last less than 90 days to over three years.
The authors offer a few explanations of why solitary confinement increases rates of recidivism, mentioning the SHU syndrome reported by Grassian in 1983 which included hallucinations, delusions, difficulties in thinking and memory, depression and anxiety and impulse control issues. Additionally solitary confinement can increase depression and PTSD symptoms which can affect recidivism. Prisoners in solitary confinement do not have access to programs and treatments. Mental health treatment is very reduced and difficult to monitor and care for. Mental illness that does not receive treatment increases the risk of recidivism. Vocational and educational programs are not offered, or are severely restricted, in solitary confinement, even though studies show that these programs reduce recidivism. Also, visits from family and friends do not happen in solitary confinement, which reduces social ties and support. Limiting these things means the inmate is less well prepared for release and has a greater risk of recidivism. Finally, the process of institutionalisation can be worsened by solitary confinement. Institutionalisation involves more suspicion and hyper vigilance by the prisoner, social isolation and a lessened self concept.
No negative effects
In a literature review in 2006, Smith found only two studies which found no negative effects on the health of prisoners in solitary confinement. These were Suedfeld et al. (1982) and Zinger and Wichmann (1999). In Suedfeld et al. (1982), the authors found various negative effects on the health of prisoners in solitary confinement including difficulty in adapting, sleep and concentration, dizziness, anger, apathy and memory problems. The authors did not, however, consider these as objective negative effects on prisoners health. In Zinger and Wichmann (1999), the authors found no adverse effects of solitary confinement on a sample of 23 inmates, 10 of which were being involuntarily segregated. There was no comparison group included. The authors told inmates that they would inform prison officials of anything they said which was about their or the prison’s safety, which could lead to prisoners not reporting symptoms. Because of these problems, the authors concluded that their study was immaterial as it did not reflect the actual use of solitary confinement in prisons.
In 2010, O’Keefe et al. found no adverse effects of solitary confinement on inmates. This is referred to as the Colorado study. They found there was no increase in mental health symptoms for those in solitary confinement and that there was improvement in the functioning of cognitive performance and that more mentally ill prisoners improved than were harmed. In a meta analysis by Morgan et al. (2016) it was found there were small to moderate effect sizes of solitary confinement on a range of outcomes such as psychological and medical outcomes. They claim the effects of imprisonment generally may be the same as solitary confinement with two exceptions - mood disturbance and self harm. The meta-analysis show a small effect of solitary confinement on recidivism and antisocial behaviours and that there may be a small decrease in inmate violence. The studies found adverse effect but these were small and are were considered to be the same as the effects of incarceration in general.
In 2018, Haney reviewed the O’Keefe research and the Morgan et al. meta analysis. Haney found major methodological problems with both of these pieces of research. In the Colorado study the control group was not matched to the solitary confinement group on appropriate characteristics (such as age, prior incarceration history, mental health problems and race). Both the solitary confinement group and the control group in this research were pulled from the group of inmates who were going to have a hearing about whether or not they would be put in solitary confinement. Those in the control group were those who were sent back to the general population after their hearing. This led to a major problem because everyone who was scheduled to be in a hearing was put into punitive segregation before the hearing for days or weeks. This meant that everyone in the sample was put through the treatment of harsh segregation before the study even began. It is unknown if the experience of punitive segregation affected the inmates adversely and if it continued to affect them throughout the study. Additionally, those in solitary confinement may have seen it as less harsh than punitive segregation and were therefore happier to be in solitary confinement than punitive segregation. This could have been the reason behind there being found no differences between the solitary confinement and the general population inmates in the research and for improvement found in solitary confinement sample. Haney also notes that there was cross contamination between the treatment and control group as inmates moved between solitary confinement and the general population as well as to punitive segregation, hospital and community placement. The groups experienced both the treatment and control conditions, and the groups cannot be compared to produce any meaningful results. There were additional problems with this research including sample bias and the inclusion of protective custody in the treatment group which is a different psychological experience for inmates. Finally, the researcher who collected the data was inexperienced and how the data was collected was flawed, including not telling the prisoners the truth about the experiment and assuming some of the prisoners were lying on their questionnaires and including these in the final analysis. Twenty percent of the participants either dropped out or were judged to be untruthful but these answers were still used in the analysis.
Haney also responded to the Morgan et al (2016) meta analysis and found it to be flawed. They included only quantitative studies on solitary confinement whereas most research has been qualitative. This introduces a sample bias from the beginning of the meta analysis. Additionally they used the Colorado study extensively in their meta analysis. In the first analysis, 24 of 50 of the effect sizes were extracted from the Colorado Study and in the second, 140 of the 210 effect sizes were also from that study. The researchers did not question these results and relied on them to make up a large part of their analysis. It was claimed that the study was “the most sophisticated study” ever done on solitary confinement. Other research relied on by the meta analysis was also flawed, or 50 years old. Some of the studies used volunteers instead of inmates and their volunteers were in solitary confinement for very short amounts of time. The meta-analysis uses a cherry picked selection of studies which have flawed results and concluded that there is only small to moderate effects on psychological functioning in solitary confinement and that these effects are no different than being in general population. It is misleading because it does not include the majority of information and relies on faulty research.
Chadick et al. (2018) found no change in inmates’ psychological functioning who were in solitary confinement for between 1 and 4 years. Twenty four males in solitary confinement were matched (some only approximately matched) to 24 inmates in general population. They claim solitary confinement had a significant effect on test scores for anxiety, dysthymia, PTSD and major depression. However, only anxiety and PTSD scores increased for the solitary confinement prisoners and the other effects seem to be found because of improvements of those in the general population. They argued that the increase in mental health symptoms did not reach a level to be addressed by treatment and so those in solitary confinement stay the same whereas those in general population seem to improve (maybe because of access to treatment). There are some key limitations of this study such as the small sample size which reduces statistical power and the fact that severely mentally ill prisoners may have been removed from solitary confinement and were therefore not included in the sample. Additionally, researchers were not able to know if inmates on solitary confinement were removed to crisis watch, which may have shown temporary mental health problems were treated and then returned to baseline levels.
Experiments failing to find negative effects could have methodological problems or it might be due to the sample, that is, if using volunteers this may not be an accurate comparison to prisoners in solitary confinement. Many inmates hide their psychological problems from guards and won’t report issues. Many guards also see any request for help from prisoners as prisoners manipulating the guards. Prisoners’ reactions to solitary confinement are also due to individual factors and coping skills. Some prisoners will have no reaction to being in solitary for long periods of time and some will deteriorate after a little time in solitary confinement.
Overall, there is a long history of research showing the adverse effects of using solitary confinement. Some studies have found no effect of solitary confinement but those studies are flawed and cannot be trusted. From this history of solitary confinement research it is clear that solitary confinement should not be used in prisons, especially for the large amounts of time that it is used in supermax prisons. In the next article I will look at recent research from the past 5 years into solitary confinement.