Mental Health

Health service contacts for mental health and substance use on release from prison: a retrospective population-based data linkage study.

TL;DR

People released from prison had significantly higher rates of mental health and substance use-related health service contacts across all services compared to a matched general population sample, with particularly disproportionate rates for emergency and unscheduled care, suggesting early support is either inadequate or not accessed by those in greatest need.

Key Findings

People released from prison had substantially higher rates of ambulance contacts for mental health, substance use, and dual diagnosis compared to matched general population controls.

  • aIRR for ambulance contacts for mental health: 7.75 (95% CI 5.76 to 10.42)
  • aIRR for ambulance contacts for substance use: 7.58 (95% CI 5.71 to 10.08)
  • aIRR for ambulance contacts for dual diagnosis: 8.28 (95% CI 6.50 to 10.55)
  • Models were adjusted for time-in-community, pre-index mental health and substance use-related health service contacts, and comorbidities

Accident and emergency department contact rates for mental health and substance use were markedly elevated among people released from prison.

  • aIRR for A&E contacts for mental health: 4.88 (95% CI 3.78 to 6.29)
  • aIRR for A&E contacts for substance use: 7.98 (95% CI 5.71 to 11.17)
  • These were among the highest ratios observed across service types, indicating disproportionate emergency care use

Out-of-hours general practice contacts for mental health, substance use, and dual diagnosis were significantly elevated for people released from prison.

  • aIRR for out-of-hours GP for mental health: 5.14 (95% CI 3.66 to 7.22)
  • aIRR for out-of-hours GP for substance use: 5.89 (95% CI 3.11 to 11.14)
  • aIRR for out-of-hours GP for dual diagnosis: 8.85 (95% CI 2.94 to 26.63)

24-hour unscheduled telephone support contacts for mental health and substance use were substantially higher among people released from prison.

  • aIRR for 24-hour unscheduled telephone support for mental health: 7.63 (95% CI 4.93 to 11.83)
  • aIRR for 24-hour unscheduled telephone support for substance use: 8.29 (95% CI 3.99 to 17.22)

Community prescription rates for mental health and substance use were elevated for people released from prison compared to matched controls.

  • aIRR for community prescriptions for mental health: 1.80 (95% CI 1.67 to 1.94)
  • aIRR for community prescriptions for substance use: 5.95 (95% CI 4.83 to 7.32)
  • aIRR for community prescriptions for dual diagnosis: 5.33 (95% CI 3.70 to 7.68)
  • The mental health prescription ratio was the lowest aIRR observed across all service types, suggesting relatively better access to routine prescribing

Drug and alcohol service contact rates and outpatient attendance rates were significantly higher for people released from prison.

  • aIRR for drug and alcohol services: 7.13 (95% CI 6.00 to 8.48)
  • aIRR for outpatient attendances: 2.61 (95% CI 2.17 to 3.16)

General and acute hospital admissions and day cases for mental health, substance use, and dual diagnosis were significantly elevated among people released from prison.

  • aIRR for general/acute hospital admissions for mental health: 2.97 (95% CI 1.43 to 6.16)
  • aIRR for general/acute hospital admissions for substance use: 7.85 (95% CI 4.42 to 13.91)
  • aIRR for general/acute hospital admissions for dual diagnosis: 13.11 (95% CI 7.95 to 21.61)
  • The dual diagnosis aIRR of 13.11 was among the highest observed across all service categories

Psychiatric admission rates for mental health, substance use, and dual diagnosis were significantly higher for people released from prison.

  • aIRR for psychiatric admissions for mental health: 3.62 (95% CI 2.39 to 5.49)
  • aIRR for psychiatric admissions for substance use: 10.74 (95% CI 6.12 to 18.84)
  • aIRR for psychiatric admissions for dual diagnosis: 7.74 (95% CI 4.30 to 13.94)

The study linked records for 8313 people released from Scottish prisons in 2015 and 41,213 matched general population individuals using nationwide administrative data.

  • Exposed group comprised all people released from any Scottish prison in 2015
  • Unexposed group was a random general population sample matched at a 1:5 ratio on sex, age, postcode, and deprivation indices, with no imprisonment in the 5 years prior
  • Linked data included prescriptions, outpatient, inpatient, emergency/unscheduled care (2010–2020), prison admissions and releases (2010–2020), and deaths records (2015–2020)
  • Analysis used fixed-effects Poisson regression with cluster-robust standard errors, stratified by mental health (MH), substance use (SU), and dual diagnosis

Despite elevated rates of contact with community mental health and substance use services, people released from prison had disproportionately high rates of contact with emergency and unscheduled care services.

  • Emergency and unscheduled care aIRRs were consistently among the highest across all service types for both mental health and substance use categories
  • Authors interpreted this pattern as suggesting 'early support is either inadequate or not accessed by those in greatest need'
  • Authors recommended 'investment in tailored transitional and post-release intervention at individual and population level'
  • Authors also noted 'high-quality care must be available and accessible beyond the immediate post-release period to permit sustained engagement or engagement at a later date'

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Citation

Connell C, Kjellgren R, Savinc J, Dougall N, Kurdi A, Watson J, et al.. (2026). Health service contacts for mental health and substance use on release from prison: a retrospective population-based data linkage study.. BMJ open. https://doi.org/10.1136/bmjopen-2025-107586