Health characteristics and court diversion among adults with psychosis in the New South Wales Local Court: A data-linkage study

BACKGROUND: Diversionary approaches seek to address criminal legal system involvement among people with psychosis and other mental illness. There is limited evidence examining health characteristics of people with psychosis in Australian criminal legal systems and how these vary with court outcomes, including diversion. METHODS: We conducted a data-linkage study of 21,229 adults hospitalised with psychosis in New South Wales (June 2001 to December 2019) with a subsequent offence finalised in the New South Wales Local Court. We described psychosis types, co-occurring conditions and prior health service use and examined their associations with court outcome (diversion vs conviction) using logistic regression, adjusting for sociodemographic and legal factors. RESULTS: A total of 70.8% of participants had a schizophrenia spectrum disorder (substance-induced psychosis 22.6%; affective psychosis 6.6%). Co-occurring conditions were common (lifetime substance-related harm 84.8%; personality disorder 41.3%; neurodevelopmental disorder 17.5%; physical condition 25.6%), and 76.3% used mental health services in the year before the index offence. Affective and substance-induced psychoses were negatively associated with diversion vs schizophrenia spectrum disorders (adjusted odds ratios = 0.64 [95% confidence interval = 0.54-0.74] and 0.29 [95% confidence interval = 0.26-0.33], respectively). Duration of psychosis admissions and past-year mental health service use were positively associated with diversion, while in those with schizophrenia spectrum disorders, lifetime substance-related harm was negatively associated. CONCLUSION: Court defendants with psychosis have a complex health profile. Although people with schizophrenia spectrum disorders are more likely to be diverted than those with other psychosis types, substance use may inhibit diversion. Health and criminal legal system collaboration is needed to facilitate diversion and treatment for this group.