People with pre-existing vulnerabilities (e.g. mental health issues or survivors of torture) are at particular risk of harm from the effects of detention. Immigration Removal Centres (IRCs) are likely to precipitate a significant deterioration of mental health in most cases, greatly increasing suffering and the risk of suicide. Some people held in detention deteriorate to the point of requiring hospitalisation.

Despite the increased need of people in detention, the provisions for mental health care in IRCs is less than that offered in the community.

In some cases a detained person has deteriorated to the point that they are transferred to a psychiatric hospital unit. Once they have recovered, they are often transferred back to the IRC, which was the environment that led to deterioration in their mental health in the first place, so generating a downward, vicious cycle.

The verdict of the jury in the inquest into the death of Brian Dalrymple at Colnbrook IRC was that the death was “contributed to by neglect”. The inquest demonstrated that a failure to diagnose underlying mental health issues and delayed psychiatric assessment contributed to Mr Dalrymple’s eventual death from natural causes whilst held in segregation.

The inquest into the death of Prince Fosu at Harmondsworth IRC also found that neglect contributed to the death. Prince Fosu died days after being detained at Harmondsworth. He suffered undiagnosed, untreated psychosis and related bizarre behaviour, dehydration, malnourishment and hypothermia. He died alone, on the concrete floor of a ‘strip cell’ in segregation with no mattress, having had little if any food, fluid or sleep.  He was naked, emaciated, and covered in debris.

The cases of “inhuman and degrading treatment” and deaths in detention are the extreme end of the spectrum, however, the shortcomings in mental health provisions in detention affects thousands of detainees every year.

These failures come at a great cost to individuals and to the detriment of their mental and physical health. Many continue to struggle with these issues long after they are released from detention.

Medical Justice believes, in line with academic research, that all immigration detention is harmful to the health of those detained, however, indefinite detention is particularly harmful. Not being able to know the likely length of detention means that even detainees that are held for a relatively short period of time suffer the devastating psychological effects and the wider human cost of indefinite detention.

Position of the Royal College of Psychiatrists

The Royal College of Psychiatrists (RC Psych) is concerned about the extent of the mental health care that can be provided in immigration detention ; “treatment of mental illness requires a holistic approach and continuity of care; it is not just the treatment of an episode of mental ill health but an ongoing therapeutic input focusing on recovery and relapse prevention. Psychotropic medication by itself is very unlikely to achieve good outcomes unless it is given as part of a broader multi-modal therapeutic approach. Detention also severs the links with family and social support networks, adversely affecting recovery. For these reasons, the recovery model cannot be implemented effectively in a detention centre setting.” Read the RC Psych’s Position Statement here).

Research on the effect of immigration detention on mental health

It has been known for many years that the prevalence of mental health problems is very high in immigration detention. A recent systematic review of the existing clinical literature on this topic by Verhülsdonk and colleagues (2021)[1], including four separate studies of people in immigration detention in the UK, shows the extent of this issue: three quarters of people in immigration detention experienced depression, more than half experienced anxiety and almost half experienced post-traumatic stress disorder. The prevalence of all three disorders was around twice as high in detained refugees and migrants compared to non-detained refugees and migrants.

This analysis replicates previous research, which has consistently found a negative impact of immigration detention on mental health. This was summarised in Mary Bosworth’s review of the mental health literature for Stephen Shaw’s (2016) report to the Home Office on the Welfare in Detention of Vulnerable Persons:

‘literature from across all the different bodies of work and jurisdictions consistently finds evidence of a negative impact of detention on the mental health of detainees’. [2]

This effect is proportionate to the time spent in detention. A systematic review by Von Werthern and colleagues (2018) found that all five adult studies which had examined the association between detention duration and mental health deterioration showed a significant relationship, with the duration of detention correlating with the severity of mental health symptoms.[3]

It is thought that there are multiple underlying mechanisms leading to the extent of this negative impact, although research into these mechanisms is lacking. People in detention have described a range of factors contributing to this including fear for their safety, criminalisation, and experiences of physical and verbal abuse. All of these contribute to experiences of loss of agency, entrapment and feelings of hopelessness. Accordingly, Verhülsdonk and colleagues conclude, “The only efficient way to improve the detainees’ mental health is to release them from detention.” [4]

A proportion of people have been transferred to immigration detention after completion of their prison sentence. Attention to the mental health risks of this group is particularly needed, due to specific vulnerabilities in this population, including a higher prevalence of autistic spectrum disorders and attention-deficit hyperactivity disorder, alongside problems associated with substance use disorders. Recent clinical research identified greater unmet needs reported by ex-foreign national prisoners in immigration detention compared to other immigration detainees, alongside this group spending longer periods in immigration detention.[5]

In summary, the consistent professional and research consensus over many years shows a significant harmful impact of immigration detention, in which people who did not have a mental health condition prior to detention are more likely to develop one, those who do have a mental health condition are likely to deteriorate, and these risks continue to increase the longer people are detained for. The harm this causes also does not end when the person is released: Three clinical studies which went on to reassess people after release from immigration detention identified that symptoms of depression, anxiety and PTSD persisted well beyond release, persisting at ten months, three years, and four years.[6]


[1] Verhülsdonk, I., Shahab, M., & Molendijk, M. (2021). Prevalence of psychiatric disorders among refugees and migrants in immigration detention: Systematic review with meta-analysis. BJPsych Open, 7(6)

[2] Bosworth M (2016) Appendix 5: The Mental Health Literature Survey Sub-Review. In Shaw (2016), Review into the Welfare in Detention of Vulnerable Persons: A Report to the Home Office.

[3] M von Werthern, K Robjant, Z Chui et al. (2018) The impact of immigration detention on mental health: a systematic review, BMC Psychiatry 18: 382

[4] Verhülsdonk, I., Shahab, M., & Molendijk, M. (2021). Prevalence of psychiatric disorders among refugees and migrants in immigration detention: Systematic review with meta-analysis. BJPsych Open, 7(6)

[5] Sen, Piyal & Crowley, Grace & Moro, Claira & Slade, Karen & Khan, Al Aditya & Katona, Cornelius & Forrester, Andrew. (2021). Mental health in immigration detention: A comparison of foreign national ex‐prisoners and other detainees. Criminal Behaviour and Mental Health. 31. 275-287

[6] M von Werthern, K Robjant, Z Chui et al. (2018) The impact of immigration detention on mental health: a systematic review, BMC Psychiatry 18: 382