Impact of post-release community mental health and disability support on reincarceration for prisoners with intellectual disability and serious mental illness in NSW, Australia

BACKGROUND: Prisoners with an intellectual disability are overrepresented in custody and more likely to reoffend and be reincarcerated compared with the general prison population. Although prisoners with intellectual disability have many of the same risk factors for recidivism as the general prison population, the high rates of mental illness experienced by this group are key drivers of recidivism. AIMS: We aimed to assess the impact of provision of post-release disability and community mental health support on rates of reincarceration in a cohort with identified intellectual disability and serious mental illness diagnosis. METHOD: We conducted a historical cohort study using linked administrative data-sets, including data on hospital admissions, community mental health, disability support and corrections custody in New South Wales, Australia (n = 484). To assess the time to return to adult custody, we used survival analysis on multiple failure-time data. RESULTS: Over the median follow-up period of 7.4 years, 73.7% (357) received community mental health support, 19.8% (96) received disability support and 18.6% (85) received a combination of supports during a post-release period from prison. Lower hazards of reincarceration in a post-release period were associated with receipt of community mental health support (hazard ratio [HR] = 0.58, CI 0.49–0.69, P < 0.001), or a combination of community mental health and disability support (HR = 0.46, CI 0.34–0.61, P < 0.001). CONCLUSIONS: High rates of reincarceration for prisoners with intellectual disability and history of serious mental illness may be modifiable by provision of appropriate mental health and disability supports.