Brain health and brain ageing in prisons

One good way to understand the detrimental effects of life experience and the environment on brain health and the ageing process is to examine the lived experiences of older incarcerated individuals or those who were formerly incarcerated in antiquated prison systems that are creaking at the seams.

The prison population is ageing worldwide, and this demographic trend is a growing concern and a public health crisis. Projections suggest that by 2030, one-third of the prison population globally will comprise individuals aged 50 and over. In Ireland, 10% of those in custody in 2015 were over the age of 50. By 2023, this figure had increased to 18.2 per cent. This represents a twofold increase in just a decade.

Most prisons were constructed in the nineteenth or early twentieth centuries, with little regard for the elderly or cognitively impaired. These facilities are not age-appropriate and frequently fail to meet the complex needs of older prisoners, particularly those with cognitive impairment. In many cases, the design and operation of prisons actively disadvantage older inmates, particularly those with neurocognitive disorders.

As outdated, understaffed and underfunded prisons grapple with this ageing demographic, more prisoners are dying behind bars or developing dementia during their incarceration. These are not necessarily individuals serving life sentences, but prison becomes their sentence for life, as their lives are effectively cut short due to the compounded effects of poor physical, mental, and brain health in prison.

Health of older prisoners

Older prisoners have poorer health and more disability compared to age-matched community controls (Novisky et al.  2025). Incarceration impacts mortality and healthy life expectancy: it has been estimated that each year spent in prison translates into a 2-year reduction in total life span (Patterson, 2013). In the UK, prisoners die from natural causes 20 years earlier than in the general population (McLintock and Sheard 2024).

The increased health vulnerabilities of this population are well documented, due to poor underlying health, overcrowding, poor healthcare assessment and monitoring and delays in access to health care.  As an example of this increased susceptibility, during the COVID pandemic, prisoners in California were 3 times more likely to die from COVID than the general population, and prisoners over 55 years were more likely to be hospitalised, be admitted to ICU or die.  

The disability with the highest frequency in older prisoners is cognitive difficulty, which is over twice as common in older prisoners compared to people living in the community (Miller et al. 2024). Despite this,  prisons lack adequate protocols to assess and care for inmates with mild cognitive impairment or dementia. This reflects a significant gap in addressing the needs of older prisoners.

Impact of prisons on brain health

The prison environment itself is not conducive to ageing and older people.  Incarceration accelerates the ageing process and exacerbates most risk factors that are detrimental to brain health. For example, loneliness, isolation, depression, poor diet, lack of cognitive and social stimulation, limited physical activity, and chronic stress are inherent to prison life. Overcrowding, substandard living conditions, victimisation, and traumatic brain injuries (TBI), either pre-existing or new due to assaults and violence in prison, further compound these issues. Furthermore, many prisoners enter the system already weighted down by a lifetime of adversity—poverty, poor education, mental health struggles, TBI and substance abuse—creating a cumulative effect that accelerates brain ageing and deteriorates overall health.

Brain health in prisoners

Regarding brain health, many prisoners carry with them a high burden of risk factors. TBI is a particularly important brain health risk factor. The prevalence of TBI in prison populations is approximately 40-60%, far higher than the lifetime prevalence in the community. One meta-analysis found that the overall estimate of TBI prevalence was 45.8% across all studies and 32.0% for moderate-to-severe TBI (Hunter et al. 2023). TBI is a  risk factor for incarceration, and being in prison puts an individual at risk of further TBI due to assault. Men and women who had sustained a TBI are about 2.5 times more likely to be incarcerated than men and women who have not sustained a TBI (McIsaac et al. 2016). The most common causes of TBI in male and female prisoners are road traffic accidents and assaults (Schneider et al. 2022). A history of TBI in prisoners is associated with poor psychosocial outcomes, including violence, repeat incarceration rates, cognitive impairment, mood disorders, psychosis, substance use disorders, and socioeconomic deprivation (Bickle et al. 2024).

 

Although there is limited data available on the subject, loneliness is a universal experience in prison. Approximately one in five inmates, i.e., those that are segregated, can spend over 22 hours isolated in their cells, and while others experience overcrowded conditions, there is a stark emotional distance between prisoners and a disruption of family social ties and support. The antiquated physical infrastructure does not support social connections. Loneliness in prisons increases mental health distress and depression and contributes to suicidality. The experience of physical overcrowding without emotional connection has been described as the major driver of emotional loneliness and mental health problems like depression and anxiety, while the presence of social supports through family contacts and the adaptation of rituals and routines are the best coping mechanisms (Pat et al. 2023).  Another significant contributor to the development of poor brain health in prisoners is cardiovascular and metabolic risk factors.  Incarcerated individuals have a disproportionate number of cardiovascular risk factors,  including smoking, an increased prevalence of hypertension and diabetes, and older heart age and higher cardiovascular risk scores (Gray et al. 2022)), all of which are associated with cardiovascular deaths, accelerated brain ageing and the risk of developing dementia (Huang et al. 2024).

 

Improving brain health in prisons

What steps could be taken to promote better brain health and successful ageing in prisons? Prisons are places that harm brain health but could be transformed to support brain health.  Some prison systems have begun incorporating the concept of "successful ageing" as part of their rehabilitation strategies for older prisoners, with a focus on physical and mental health and engagement with life. Expanding this approach to include risk reduction and brain health promotion offers an opportunity for positive change. Improving brain health should become an integral goal of prison rehabilitation systems. To achieve this, older prisoners must have the opportunity to engage in activities that provide purpose and meaning and receive the appropriate care and support from trained personnel in a brain health-friendly environment. This can only be achieved by a systems level. Significant changes and funding would be required, including redesigning prison environments to provide access to outdoor and green spaces, fostering social connections and social capital and trust, and offering creative activities that reduce depression, loneliness, and isolation. Comprehensive training and education for prison staff on dementia care, cognitive assessment, and brain health promotion are also critical. Additionally, prisons should establish clear pathways for the assessment and care of inmates with cognitive impairment, with and without mental health disorders. While these changes may sound ambitious, they would provide a solid framework for improving the quality of life, rehabilitation outcomes, and overall health and well-being of older prisoners.

Why use a brain health framework? Cognitive difficulties are the main disability in ageing prisoners. Focusing on a brain health framework in prisons will address what matters most and would reduce further risks to brain health. Cognitive health is a major determinant of successful release from prison; a brain health framework would inform decisions regarding continued incarceration or alternative forms of supervision and detention, paving the way for more humane and effective health-promoting approaches within the prison system.

 

 

 

 

What the future holds for ageing and dementia in prisons

If you want to see what the future holds for ageing prisoners, look to Japan. What’s happening in the rest of the world is unplanned but totally predictable based on trends in Japan, which has the highest proportion of older people in the world and the greatest number of older prisoners in the world. Japanese prisons have become like care homes and, paradoxically, places of refuge for older people, particularly older women, some of whom offend repeatedly because life is more comfortable in prison than living on the street or alone on their own. For example, regarding Japanese inmates released in 2022, the two-year reimprisonment rate was 13.2% for men and 10.8% for women. However, the highest rate was 18.3% for those aged 65 and older, compared to 8.2% for those under 30 https://journals.sagepub.com/doi/10.1177/0306624X251348606#bibr16-0306624X251348606.

These numbers contrast with those in other nations, where reoffending rates tend to decrease with age and recidivism and reimprisonment are higher in younger age groups.  The epidemic of loneliness among the elderly in Japan, where roughly 20% of the population lives in poverty, has been one of the social forces behind this trend.  For all of these reasons, reintegrating older inmates into society after incarceration is becoming more and more challenging.

Most countries are currently experiencing these trends at different stages of development, but there is little advance planning or policy in place to address them. 

 

 

 

 

Ageing, dementia and cognitive impairment in prisons

The ageing of prison populations and the intersection of cognitive impairment and the criminal justice system present several challenges for prison systems globally. First, there is an increasing prevalence of mild cognitive impairment (MCI) and dementia in prisons due to the ageing profile of inmates; second, the increase in MCI and dementia in prisons raises costs and creates complexities for the assessment and management of  these prisoners during their confinement;  incarceration costs are significantly higher for older adults compared to younger adults because of higher disease burden and a dementia and cognitive impairment diagnosis raise the cost and caring stakes considerably more; third cognitive impairment and dementia can be important causes or contributing factors  to criminal behaviour and may be undiagnosed at the time of arrest ; and finally, a dementia diagnosis is a significant impediment to the release of older prisoner back to the community.

 

Prevalence of dementia and cognitive impairment in prisons

Data are scarce on rates of cognitive impairment and dementia in older prison populations and even less information on dementia subtypes. The pooled prevalence of dementia of 6.9%.  This is consistent with data from the UK that found a prevalence rate of 7% in male and 6% in female prisoners, which is 3.5 times higher than their community counterparts (Forsyth et al. 2025).  The highest prevalence rate was in prisoners aged over 70 years at about 12%.  Most of these individuals did not have a formal diagnosis of dementia in the chart, and over 40% represented a high or very high risk of harm to self or others.

 

Incarceration as a risk for dementia and MCI

Incarceration is a risk factor for cognitive decline and dementia. Individuals over age 50 years with a criminal record or incarceration had a 1.5-2.7 times higher risk of developing dementia and MCI, attributed to substance misuse, low education and adverse life experiences, chronic stress, and pre-existing cognitive deficits, which disproportionately occur in prison populations, contributing to this increased risk (Solares et al. 2023; Cox & Wallace).  Older adults who have committed serious crimes, being convicted multiple times, or receiving long prison sentences were found to have a significantly higher risk   of dementia (Solares et al. 2020). Incarceration is associated with an earlier onset (Cox & Wallace, 2022; Tanksley et al., 2023), and steeper declines in cognition over time (Testa, Mijares, & Jackson, 2025). When education is controlled for, the effects of incarceration become non-significant (Tanskey et al. 2023). Importantly, pre-existing MCI and dementia may be an important factor in this increased risk. In one study from the USA, 3.3% had a diagnosis of either dementia (2.5%) or MCI (0.8%) before their most recent incarceration (Kuffel et al. 2022).

 

Dementia and cognitive impairment as a contributor to criminal behaviour

The other side of the coin is how criminal behaviour can be a symptom or presentation of dementia and an entry point into the criminal justice system. The prevalence of criminal behaviour is highest in behavioural variant frontotemporal dementia (bvFTD) and semantic dementia but low in vascular dementia and Huntington’s disease and Alzheimer’s disease and lowest in Parkinsonian syndromes. When criminal behaviour occurs, it is over-represented in males, tends to occur early in the disease and declines thereafter (Schroeter et al. 2025). Criminal behaviour occurs more commonly in alcohol-related neurocognitive disorders, e.g., alcohol-related dementia and Wernicke-Korsakoff syndrome (Palm et al. 2025).

Criminal behaviour related to dementia is more likely to be diagnosed after arrest. Among individuals within the South Carolina Department of Corrections who had a dementia-related diagnosis, 11% were diagnosed with dementia before their arrest and 89% were diagnosed after arrest.

Another major challenge posed by the ageing prison population and the increased prevalence of dementia in older prisoners is the difficulty with their discharge.  Finding resources, accommodation and support for individuals with dementia and a criminal record will significantly impact on release efforts.

 

Implications

The prison population is ageing worldwide, and more older prisoners with a multitude of dementia risk factors are developing MCI and dementia while incarcerated. Most of these cases of MCI and dementia are undetected and undiagnosed. In addition, a significant proportion of prisoners are entering the prison system because of criminal behaviour that is either due to dementia or the reason for their arrest is contributed to by neurocognitive issues, all of which makes their care and supervision more complex and costly. Furthermore, the existence or emergence of dementia or cognitive impairment is a critical determining factor in achieving a successful transition back to the community post-incarceration.  For all these reasons, there is an urgent need to develop assessment, care and intervention protocols for dementia that are equivalent and aligned with those already in existence in the community. This means considerable investment in capacity building, the training and education of staff and the modernisation of the design of the physical environment, but most of all, it requires the determination and moral imagination of policymakers if we are to overcome the overwhelming stigma, discrimination and brain health inequalities that our prisons and prisoners experience. 

 

References

Bickle, A., Al Shammaa, T., Musa, E., Arya, P., & Khalifa, N. (2024). Traumatic brain injury in criminal justice systems: a systematic literature review. The Journal of Forensic Psychiatry & Psychology, 35(2), 206–228. https://doi.org/10.1080/14789949.2024.2313451

 

Cox RJA, Wallace RB. The Role of Incarceration as a Risk Factor for Cognitive Impairment. J Gerontol B Psychol Sci Soc Sci. 2022 Dec 29;77(12):e247-e262. doi: 10.1093/geronb/gbac138. PMID: 36153747; PMCID: PMC9799218.

 

Gray BJ, Craddock C, Couzens Z, Dunseath GJ, Shankar AG, Luzio SD, Perrett SE. Quantifying cardiovascular disease risk and heart age predictions for men in the prison environment. Public Health. 2023 Dec;225:285-290. doi: 10.1016/j.puhe.2023.10.026. Epub 2023 Nov 11. PMID: 37956640.

 

Forsyth K, Malik B, Webb R, et al

Prevalence of dementia and mild cognitive impairment among the older prisoner population in England and Wales: a cross-sectional study

BMJ Open 2025;15:e095577. doi: 10.1136/bmjopen-2024-095577

 

Huang H, Wang J, Dunk MM, Guo J, Dove A, Ma J, Bennett DA, Xu W. Association of Cardiovascular Health With Brain Age Estimated Using Machine Learning Methods in Middle-Aged and Older Adults. Neurology. 2024 Jul 23;103(2):e209530. doi: 10.1212/WNL.0000000000209530. Epub 2024 Jun 18. PMID: 38889383; PMCID: PMC11226327.

 

Hunter, S., Kois, L. E., Peck, A. T., Elbogen, E. B., & LaDuke, C. (2023). The prevalence of traumatic brain injury (TBI) among people impacted by the criminal legal system: An updated meta-analysis and subgroup analyses. Law and Human Behavior, 47(5), 539–565. https://doi.org/10.1037/lhb0000543

 

McIsaac KE, Moser A, Moineddin R, Keown LA, Wilton G, Stewart LA, Colantonio A, Nathens AB, Matheson FI. Association between traumatic brain injury and incarceration: a population-based cohort study. CMAJ Open. 2016 Dec 6;4(4):E746-E753. doi: 10.9778/cmajo.20160072. PMID: 28018890; PMCID: PMC5173464.

 

Kuffel RL, Byers AL, Williams B, Fortinsky R, Li Y, Ruderman MA, Barry LC. Prevalence of dementia and mild cognitive impairment before incarceration. J Am Geriatr Soc. 2022 Jun;70(6):1792-1799. doi: 10.1111/jgs.17724. Epub 2022 Feb 25. PMID: 35212389; PMCID: PMC9177569.

 

Miller KEM, Shen K, Yang Y, Williams BA, Wolff JL. Prevalence of Disability Among Older Adults in Prison. JAMA Netw Open. 2024;7(12):e2452334. doi:10.1001/jamanetworkopen.2024.52334

 

Novisky MA, Prost SG, Fleury-Steiner B, Testa A. Linkages between incarceration and health for older adults. Health Justice. 2025 Apr 17;13(1):23. doi: 10.1186/s40352-025-00331-x. PMID: 40244545; PMCID: PMC12004771.

 

Pageau F, Seaward H, Habermeyer E, Elger B, Wangmo T. Loneliness and social isolation among the older person in a Swiss secure institution: a qualitative study. BMC Geriatr. 2022 Feb 1;22(1):90. doi: 10.1186/s12877-022-02764-7. PMID: 35105337; PMCID: PMC8806358.

 

 

Palm, A., Talaslahti, T., Vataja, R. et al. Criminal behavior in alcohol-related dementia and Wernicke–Korsakoff syndrome: a Nationwide Register Study. Eur Arch Psychiatry Clin Neurosci 275, 463–471 (2025). https://doi.org/10.1007/s00406-024-01804-0

 

Pat P, Edin K, Jegannathan B, San Sebastian M, Richter Sundberg L. "Overcrowded but lonely": exploring mental health and well-being among young prisoners in Cambodia. Int J Prison Health. 2023 Jun 28;ahead-of-print(ahead-of-print):628-640. doi: 10.1108/IJPH-02-2023-0011. PMID: 37365938; PMCID: PMC10812882

 

Patterson EJ. The dose-response of time served in prison on mortality: New York State, 1989-2003. Am J Public Health. 2013 Mar;103(3):523-8. doi: 10.2105/AJPH.2012.301148. Epub 2013 Jan 17. PMID: 23327272; PMCID: PMC3673515

 

Schneider BS, Arciniegas DB, Harenski C, Clarke GJB, Kiehl KA, Koenigs M. The prevalence, characteristics, and psychiatric correlates of traumatic brain injury in incarcerated individuals: an examination in two independent samples. Brain Inj. 2021 Dec 6;35(14):1690-1701. doi: 10.1080/02699052.2021.2013534. Epub 2022 Jan 22. PMID: 35067151; PMCID: PMC8884136.

Schroeter, M.L., Žuvela, M. & Szabo, L. Criminal minds in dementia: A systematic review and quantitative meta-analysis. Transl Psychiatry 15, 324 (2025). https://doi.org/10.1038/s41398-025-03523-

 

Solares, C., Dobrosavljevic, M., Larsson, H., Cortese, S. & Andershed, H. The mental and physical health of older offenders: A systematic review and meta-analysis. Neurosci. Biobehav. Rev. 118, 440–450. https://doi.org/10.1016/j.neubiorev.2020.07.043 (2020)

 

 

Solares, C., Garcia-Argibay, M., Chang, Z. et al. Risk of dementia and mild cognitive impairment in older adults with a criminal background: a population-based register study in Sweden. Sci Rep 13, 1915 (2023). https://doi.org/10.1038/s41598-023-28962-w

 

 

Tanksley PT, Logan MW, Barnes JC. History of incarceration and age-related neurodegeneration: Testing models of genetic and environmental risks in a longitudinal panel study of older adults. PLoS One. 2023 Dec 4;18(12):e0288303. doi: 10.1371/journal.pone.0288303. PMID:

 

Testa A, Mijares L, Jackson DB. The Impact of Prior Incarceration on Cognitive Trajectories Among Older Adults: Evidence From the Health and Retirement Study. J Gerontol B Psychol Sci Soc Sci. 2025 Jan 17;80(2):gbae194. doi: 10.1093/geronb/gbae194. PMID: 39657583; PMCID: PMC11751363.

 

Thomas L, Plugge E, Van Hout MC. "Deaf behind bars": a global scoping review on the situation and experiences of detained people with hearing impairment. Int J Prison Health (2024). 2025 Apr 29;21(2):206-217. doi: 10.1108/IJOPH-01-2025-0002. PMID: 40217573.