Mental health needs, substance use patterns, and risk of reincarceration among adults admitted to provincial prisons in British Columbia, Canada

People with mental health needs and substance use disorders (MHN/SUD) are overrepresented in all levels of the criminal justice system, including prisons. Despite this, diversion options for people with MHN/SUD are limited, and reentry supports after release from prison are inadequate. Few Canadian studies have examined MHN/SUD in custodial settings, and none have examined the relationship between MHN/SUD and reincarceration using a population-based prison sample. In this thesis I use administrative data from the government authority responsible for the management of provincial adult prisons in British Columbia (BC Corrections). Specifically, I use mental health intake screening data (from the Jail Screening Assessment Tool (JSAT)) linked to records of jail admissions and releases to examine: (1) the prevalence of mental health needs, substance use disorders, and co-occurring disorders (COD) among people admitted to custody over a 9-year period; (2) the relationship between MHN/SUD profile and time to reincarceration; and finally (3) the relationship between specific substance use profiles and frequency of reincarceration. I found that the proportion of people admitted to prison with COD increased by 17 percentage points from 2009-2017. Methamphetamine use disorder increased nearly five-fold from 6% to 29%, and heroin use disorder increased from 11% to 26%. Examining the relationship between MHN/SUD and time to reincarceration among people admitted to custody between 2012 and 2014, I found that people with COD returned to custody in the shortest period, followed closely by those with SUD only. After 3 years, 72% of those with COD returned to custody, compared to only 44% of those with no disorder. Even after adjustment for well-known risk factors, having COD remained the most important predictor of reincarceration. Examining substance-specific drug use patterns, I found that people who used methamphetamine were at high risk of multiple incarceration events, and at highest risk when used in combination with heroin. People with COD and people who use methamphetamine and/or heroin are at substantially elevated risk of frequent cycles of incarceration. Addressing the needs of people with complex clinical MHN/SUD profiles (including housing, social support, and high-quality MHN/SUD treatment) are required in the community to prevent further criminalization of this marginalized subgroup.