International Journal of Drug Policy 100 (2022) 103523 Contents lists available at ScienceDirect International Journal of Drug Policy journal homepage: www.elsevier.com/locate/drugpo Commentary Addressing the complex substance use and mental health needs of people leaving prison: Insights from developing a national inventory of services in Canada Tara Marie Watson a,∗ , Paul Victor Benassi a,b,c , Branka Agic a,c , Asha Maharaj a , Sanjeev Sockalingam a,b,d a Centre for Addiction and Mental Health (CAMH), 1000 Queen Street West, Toronto, ON, M6J 1H4, Canada b Department of Psychiatry, University of Toronto, 250 College Street, 8th floor, Toronto, ON, M5T 1R8, Canada c Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON, M5T 3M7, Canada d Institute of Medical Science, University of Toronto, 1 King’s College Circle, Toronto, ON, M5S 1A8, Canada a r t i c l e i n f o Keywords: Substance use services Mental health services Incarceration Harm reduction Community re-entry Canada a b s t r a c t Internationally, transitions from prison to the community are often precarious experiences for people who are living with substance use and mental health concerns. In Canada, a continuing opioid overdose crisis and over- lapping challenges related to the COVID-19 pandemic have generated urgency for scaling up community-based services that can meet the complex substance use and mental health needs of people leaving prison. In this commentary, we reflect on our experience with and knowledge gained by developing a national inventory of substance use and mental health services for criminal justice-involved persons who are re-entering the commu- nity. We learned that there is a scarcity of such community-based services specific to criminal justice-involved populations and a glaring lack of information about culturally safe and appropriate supports. Stakeholders from organisations across Canada identified that communities need a comprehensive array of low-barrier services, inclusive of harm reduction and substance use treatment services, to meet the diverse needs of people leaving prison. We recommend building greater investment in and awareness of community-driven, local programs, as well as enhancing efforts to engage people with lived and living experience in service design and provision. We also briefly describe a few programs to highlight examples of how to operationalise the themes that we observed to emerge while developing a national inventory of community-based substance use and mental health services for criminal justice-involved persons. In this commentary, we reflect on our experience with developing a national inventory of community-based substance use and mental health services in Canada for people who are transitioning out of correctional settings and re-entering the community. We share what we learned in the hopes that the knowledge generated from our work can be harnessed to enhance awareness, operation, and funding of these important sup- ports for people leaving prison. Background People living with substance use and mental health issues are over- represented in correctional systems worldwide (e.g., Baranyi et al., 2019; Beaudette & Stewart, 2016; Fazel & Seewald, 2012; Fazel, Yoon, & Hayes, 2017; Mental Health Commission of Canada, 2021a; Michalski, 2017; Prins, 2014), necessitating attention to the presence ∗ Corresponding author. E-mail address: TaraMarie.Watson@camh.ca (T.M. Watson). and quality of substance use and mental health supports for criminal justice-involved persons. For example, a systematic review that identi- fied 24 international studies involving a total of 18,388 prisoners found that nearly a quarter of newly incarcerated men and women had an al- cohol use disorder, with similar estimates, though potentially higher for women, for drug use disorders (Fazel et al., 2017). In Canada, our geo- graphic location, a national prevalence rate of 73% has been observed for any current mental disorder among men newly admitted to the fed- eral correctional system, with the highest prevalence rates for alcohol and substance use disorders (Beaudette & Stewart, 2016). There are multiple, often overlapping determinants that increase the likelihood of people living with substance use and mental health issues becoming incarcerated, including key social determinants of health such as income, housing, and access to quality health services (Mental Health Commission of Canada, 2020a,b). For instance, people engaging in sub- https://doi.org/10.1016/j.drugpo.2021.103523 0955-3959/© 2021 Elsevier B.V. All rights reserved.