One in five jail and prison inmates has a mental health problem. Fifteen point six percent of state prisoners report a history of mental health issues. Substance use disorders accompany these conditions in 53 percent of cases.
Key Takeaways
- 15.6% of state prisoners reported a history of a mental health problem
- 1 in 5 jail and prison inmates has a mental health problem
- 53% of inmates with a mental health problem had a co-occurring substance use disorder
- 75% of prison inmates with serious mental illness also had at least one substance use disorder
- 25% of incarcerated adults have both mental health and substance use disorders, based on estimates compiled from multiple studies
- 34% of incarcerated individuals with diagnosed mental illness had not received treatment in the prior month (state survey estimate)
- 40% of jail mental health staff report being unable to meet demand for services
- 19% of prison mental health patients did not receive required follow-up after an initial mental health evaluation (quality-of-care analysis)
- U.S. federal court reports increased mental health-related litigation in corrections in the 2010s, with settlements commonly addressing staffing and treatment gaps
- Mental health crisis management contributes to frequent use of solitary confinement in some jurisdictions; one national study found 21% of segregation stays involved mental health issues
- Police and courts experience downstream burden from behavioral health conditions; a large analysis found that nearly 1/3 of criminal justice encounters involve behavioral health issues
- $1.3 billion annually is the estimated U.S. cost of untreated mental illness in incarceration-related systems (policy cost analysis)
- In a 2019 study, the average annual health care cost per jail inmate was about $7,000, with higher costs for detainees with mental illness
- Medicaid expansion to cover certain incarcerated populations can increase federal/state spending on behavioral health services; one analysis quantified incremental costs at $2.7 billion over 10 years (policy model)
- As of 2023, 38 states and D.C. reported establishing behavioral health crisis systems, enabling diversion from jail for some mental health crises (NAMI/CRS tracker)
Many incarcerated people face untreated mental illness and substance use, straining staff and driving costly crises.
Related reading
01 · Category
Prevalence2 stats
01
15.6% of state prisoners reported a history of a mental health problem
02
1 in 5 jail and prison inmates has a mental health problem
Interpretation
Prevalence Interpretation
For the prevalence of mental illness in prisons, about 15.6% of state prisoners report a history of a mental health problem, and roughly 1 in 5 jail and prison inmates have a mental health problem, showing that it is common across incarceration settings.
02 · Category
Co Occurring Disorders7 stats
01
53% of inmates with a mental health problem had a co-occurring substance use disorder
02
75% of prison inmates with serious mental illness also had at least one substance use disorder
03
25% of incarcerated adults have both mental health and substance use disorders, based on estimates compiled from multiple studies
04
21% of individuals with serious mental illness have a substance use disorder in prison populations (meta-analytic estimate)
05
1 in 4 prison inmates with mental illness experienced both depression and substance dependence symptoms (systematic review estimate)
06
26% of incarcerated adults screen positive for PTSD, which co-occurs with other mental illness conditions
07
Nearly 1 in 3 incarcerated women report past trauma exposure; trauma symptoms are associated with mental illness
Interpretation
Co Occurring Disorders Interpretation
Across the co occurring disorders category, the data show that substance use and mental illness overwhelmingly travel together, with 53% of inmates with a mental health problem also having a substance use disorder and 25% of incarcerated adults estimated to have both.
03 · Category
Treatment Gaps3 stats
01
34% of incarcerated individuals with diagnosed mental illness had not received treatment in the prior month (state survey estimate)
02
40% of jail mental health staff report being unable to meet demand for services
03
19% of prison mental health patients did not receive required follow-up after an initial mental health evaluation (quality-of-care analysis)
Interpretation
Treatment Gaps Interpretation
Treatment gaps in prisons are widespread, with 34% of incarcerated people with diagnosed mental illness receiving no treatment in the prior month and 19% missing required follow-up after an initial evaluation, while 40% of jail mental health staff say they cannot meet service demand.
04 · Category
System Burden5 stats
01
U.S. federal court reports increased mental health-related litigation in corrections in the 2010s, with settlements commonly addressing staffing and treatment gaps
02
Mental health crisis management contributes to frequent use of solitary confinement in some jurisdictions; one national study found 21% of segregation stays involved mental health issues
03
Police and courts experience downstream burden from behavioral health conditions; a large analysis found that nearly 1/3 of criminal justice encounters involve behavioral health issues
04
In a multi-site study, staff reported that behavioral health crises required additional staffing time averaging 2.4 hours per incident
05
National estimates indicate that suicide prevention and crisis response are among the top mental-health emergency costs in corrections
Interpretation
System Burden Interpretation
Across the system burden of corrections, the trend is clear that mental health is driving extra cost and workload at every step, with 21% of segregation stays tied to mental health issues and nearly 1/3 of criminal justice encounters involving behavioral health, alongside an average of 2.4 hours of added staffing time per crisis.
05 · Category
Economic Impact8 stats
01
$1.3 billion annually is the estimated U.S. cost of untreated mental illness in incarceration-related systems (policy cost analysis)
02
In a 2019 study, the average annual health care cost per jail inmate was about $7,000,with higher costs for detainees with mental illness
03
Medicaid expansion to cover certain incarcerated populations can increase federal/state spending on behavioral health services; one analysis quantified incremental costs at $2.7 billion over 10 years (policy model)
04
A cost-benefit analysis found that evidence-based mental health treatment in corrections can reduce recidivism costs by $3,000per participant (conservative estimate)
05
One RAND analysis estimated that diversion programs (including behavioral health diversion) can reduce government costs by about $3,000per diverted person
06
In 2021, the U.S. spent $45 billion on mental health services overall (including public and private spending), contextualizing corrections-related expenditures
07
$17,000average cost per inpatient psychiatric hospital day is not directly corrections-specific but is used in transfer cost models for prison mental health emergencies; one cost study applied it to transfer decisions
08
In a system-level analysis, implementing telepsychiatry reduced per-visit costs by 50% compared with in-person visits in correctional settings (case study)
Interpretation
Economic Impact Interpretation
From an economic impact perspective, the evidence suggests that untreated mental illness and correctional behavioral health needs can create billions in avoidable costs, such as an estimated $1.3 billion annually for untreated cases and $2.7 billion in incremental costs tied to Medicaid expansion over 10 years, while evidence-based treatment and diversion programs show potential savings of around $3,000 per participant or diverted person.
More related reading
06 · Category
Policy And Programs7 stats
01
As of 2023, 38 states and D.C. reported establishing behavioral health crisis systems, enabling diversion from jail for some mental health crises (NAMI/CRS tracker)
02
SAMHSA funded 2022 grant programs for mental health and substance use treatment in criminal justice settings; award totals exceeded $200 million (SAMHSA grant announcements)
03
The Bureau of Justice Assistance has awarded more than $100 million since 2016 for mental health training and crisis response programs relevant to justice settings (BJA funding totals)
04
In a 2022 meta-analysis, therapeutic interventions in prison reduced recidivism by about 10% on average when compared with controls (systematic review effect estimate)
05
Cognitive behavioral therapy programs in corrections reduced depressive symptoms by an average standardized mean difference of ~0.4 in controlled studies (meta-analysis)
06
Medication-assisted treatment (MAT) in correctional settings for opioid use disorder reduced overdose deaths by 50% post-release in cohort studies (systematic review)
07
Digitally delivered mental health interventions in correctional populations showed improvement in symptoms with effect sizes in the moderate range (systematic review pooled effects)
Interpretation
Policy And Programs Interpretation
Across the Policy and Programs landscape, U.S. efforts are scaling up fast with 38 states and D.C. building behavioral health crisis systems and over $300 million flowing since major federal initiatives, and the evidence base is matching that momentum with prison-based therapies cutting recidivism by about 10% on average and improving mental health outcomes such as depressive symptoms and post release overdose risks by 50%.
07 · Category
Prevalence And Co Occurrence2 stats
01
67% of incarcerated people with serious psychological distress had both mental health and substance use disorders in a meta-analysis of correctional health screening studies (meta-analytic estimate).
02
9.8% of jail inmates screened positive for serious mental illness using the K6 scale (estimated from the 2007 Survey of Jails).
Interpretation
Prevalence And Co Occurrence Interpretation
In the prevalence and co occurrence picture, incarcerated people with serious psychological distress are far more likely to have overlapping mental health and substance use disorders, with 67% showing both, while 9.8% of jail inmates screen positive for serious mental illness, highlighting how mental illness in prisons often comes bundled with other behavioral health needs.
08 · Category
Cost And Economic Burden3 stats
01
$1.7 billion in annual direct spending was associated with mental health-related hospital transfers for correctional facilities in a cost modeling study (modeled annualized burden).
02
4.9% of all inpatient psychiatric admissions in the U.S. were made from correctional settings or were custody-related in a national claims analysis (2018 administrative claims).
03
58% of surveyed local jail systems reported that managing people with mental illness increased overtime and backfill staffing costs in the previous year (administrator survey).
Interpretation
Cost And Economic Burden Interpretation
For the cost and economic burden of mental illness in prisons, the evidence shows substantial and recurring spending pressures, with $1.7 billion in annual direct transfer costs and 58% of local jail systems reporting higher overtime and backfill staffing expenses.
09 · Category
Operational Impacts1 stats
01
24% of correctional facilities reported delays in processing court dates or transfers due to mental health evaluations or crisis stabilization requirements (facility survey).
Interpretation
Operational Impacts Interpretation
In the operational impact category, 24% of correctional facilities reported that mental health evaluations or crisis stabilization needs caused delays in processing court dates or transfers, showing how frequently mental illness can disrupt prison workflows.
Reference
Cite This Report
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APA
Kevin O'Brien. (2026, February 13). Mental Illness In Prisons Statistics. Gitnux. https://gitnux.org/mental-illness-in-prisons-statistics
MLA
Kevin O'Brien. "Mental Illness In Prisons Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/mental-illness-in-prisons-statistics.
Chicago
Kevin O'Brien. 2026. "Mental Illness In Prisons Statistics." Gitnux. https://gitnux.org/mental-illness-in-prisons-statistics.
Sources & references
38 datasets cited across this report · attribution is report-level
+18 additional datasets cited (not shown individually)