Mental health and substance use problems among people released from prison contribute substantially to premature mortality and emergency services demand. Understanding of mental health and substance use-related health service contacts prior to these severe and costly outcomes is limited. We assessed mental health and substance use-related contact with multiple services, comparing rates of contact among people released from prison to a matched general population sample who had not recently been in prison.

To compare rates of health service contacts for mental health and substance use between people released from prison and a matched general population sample.

We conducted a retrospective cohort study using linked administrative data with nationwide coverage. The cohort contained all people released from any Scottish prison in 2015 (exposed group), and a random general population sample matched (ratio 1:5) on sex, age, postcode and deprivation indices, who had no imprisonment in the 5 years prior (unexposed group). We linked individual-level administrative healthcare (prescriptions, outpatient, inpatient, emergency/unscheduled care: 2010–2020), prison (admissions, releases: 2010–2020) and deaths records (2015–2020). We estimated adjusted incidence rate ratios (aIRRs) with 95% CIs using fixed-effects Poisson regression with cluster-robust standard errors, controlling for time-in-community, pre-index mental health and substance use-related health service contacts, and comorbidities. We stratified models by mental health (MH), substance use (SU) and dual diagnosis (attributable to both MH and SU).

Scotland.

We linked records for 8313 people released from prison, and 41 213 matched individuals. Mental health and substance use-related contact rates were significantly higher for people released from prison across all services, and particularly for emergency and unscheduled care. aIRRs for ambulance contacts were MH=7.75 (95% CI 5.76 to 10.42), SU=7.58 (95% CI 5.71 to 10.08), dual diagnosis=8.28 (95% CI 6.50 to 10.55); and accident and emergency department contacts were MH=4.88 (95% CI 3.78 to 6.29) and SU=7.98 (95% CI 5.71 to 11.17). aIRRs for community prescriptions were MH=1.80 (95% CI 1.67 to 1.94), SU=5.95 (95% CI 4.83 to 7.32), dual diagnosis=5.33 (95% CI 3.70 to 7.68); drug and alcohol services were 7.13 (95% CI 6.00 to 8.48); and outpatient attendances were 2.61 (95% CI 2.17 to 3.16). aIRRs for 24-hour unscheduled telephone support were MH=7.63 (95% CI 4.93 to 11.83) and SU=8.29 (95% CI 3.99 to 17.22); and out-of-hours general practice were MH=5.14 (95% CI 3.66 to 7.22), SU=5.89 (95% CI 3.11 to 11.14) and dual diagnosis=8.85 (95% CI 2.94 to 26.63). aIRRs for general/acute hospital admissions and day cases were MH=2.97 (95% CI 1.43 to 6.16), SU=7.85 (95% CI 4.42 to 13.91), dual diagnosis=13.11 (95% CI 7.95 to 21.61); and for psychiatric admissions were MH=3.62 (95% CI 2.39 to 5.49), SU=10.74 (95% CI 6.12 to 18.84) and dual diagnosis=7.74 (95% CI 4.30 to 13.94).

Improved post-release mental health and substance use care is vital for individual and public health. Despite elevated rates of contact with community mental health and substance use services, people released from prison have disproportionately high rates of contact with emergency and unscheduled care services. This suggests that early support is either inadequate or not accessed by those in greatest need.

Policymakers and service providers should consider investment in tailored transitional and post-release intervention at individual and population level, to improve health and thus prevent later high-cost service use and avoidable mortality. Our results also suggest high-quality care must be available and accessible beyond the immediate post-release period to permit sustained engagement or engagement at a later date.

Prescribing high-dose antipsychotics is typically reserved for individuals with treatment-resistant severe mental illnesses, such as schizophrenia, bipolar disorder and psychotic depression. It carries an increased risk of adverse drug effects, necessitating regular monitoring. Non-mental health specialist clinicians may not always be aware when the maximum recommended dose of antipsychotics is exceeded, leading to unintentional high-dose prescribing without recognising the need for additional monitoring or understanding the associated risks. Therefore, providing clinical decision support (CDS) tools to support clinicians and improve the appropriate prescribing of antipsychotics is important. The aim of this study is to understand current prescribing practices and assess the impact of high-dose antipsychotic prescribing on clinical outcomes among hospitalised patients. The findings from this study will shape a future project focused on developing an integrated computerised CDS tool.

This retrospective cohort study will examine antipsychotic prescribing among hospitalised patients using Hospital Electronic Prescribing and Medicines Administration data in Scotland from 2019 to 2023, in linkage with hospital records, Scottish Morbidity Records and primary care prescribing (Prescribing Information System). Patients will be grouped into those prescribed high-dose (exposed), defined as exceeding the 100% maximum recommended British National Formulary dose and normal-dose (unexposed) antipsychotics, followed from their first ever antipsychotic prescription date (index date) until the end of the study, study outcomes or death, whichever happens first. We will quantify high-dose antipsychotic prescribing, profile patient characteristics and use machine learning techniques to assess associations of high-dose antipsychotic prescribing with clinical outcomes, including harms and benefits, but will not attempt to establish causality.

The Health and Social Care Public Benefit and Privacy Policy Panel (HSC-PBPP) has granted ethical approval (ref. 2024-0239) following a Data Protection Impact Assessment, with data securely held and accessed in the National Safe Haven. The results will be published in international peer-reviewed journals and will be shared with clinicians.