The Relationship Between Serious Mental Illness and Criminal Offending in Persons Experiencing Homelessness: The Role of Substance Use Disorder.

Individuals who live with mental illness are encumbered by related risk factors that increase the probability of legal involvement. The goal was to determine how homelessness and substance use disorder are intervening factors in the relationship between symptoms of serious mental illness (SMI) and criminal offending. A sample of 210 chronically homeless adults receiving SAMHSA-funded outreach and psychiatric rehabilitation services between 2014 and 2016 was recruited in a study of interventions to address housing in homeless persons with a SMI. Participants were interviewed and data collected were analyzed using structural equation modeling. Statistical analysis showed that homelessness severity mediated the relationship between SMI symptom severity and criminal offenses committed in the past 30 days in participants with a substance use disorder but not in those with no substance use diagnosis. Results show that homelessness and substance use are important to address to possibly alter trajectories for criminal justice involvement.