Criminal offending patterns in adults with serious mental illness: Clinical characteristics and gender as key risk factors

Adults with serious mental illness have a relatively high risk of criminal justice involvement. While causal pathways for criminal offending are complex, male gender and co-occurring substance abuse are important known risk factors. Adults with bipolar disorder have substantially higher risk of offending – including violence – than those with schizophrenia. However, the specific interaction of these risk factors has not been examined. This study explores the inter-relationship of gender, substance abuse, and psychiatric diagnosis to identify sub-groups at higher risk for offending. Administrative records of 25,133 adults with schizophrenia or bipolar disorder in Connecticut’s public behavioral health system during 2005-2007 were merged with state records of criminal convictions and incarceration. Categorical-interaction effects of gender, substance abuse, and psychiatric diagnosis on offending risk were estimated using multivariable logistic regression. Men with bipolar disorder and co-occurring substance abuse had the highest absolute risk of criminal offending, including for both violence and minor crimes. Substance abuse increased risk in women more than men, especially among those with schizophrenia. Men and women with bipolar disorder and co-occurring substance abuse had much higher risk of offending than those with schizophrenia, especially those with no substance abuse. Identifying sub-groups of adults with SMI who are at higher risk for offending, including violence as well as minor crimes, could have important implications for jail diversion and other programs that aim to divert defendants away from the justice system and instead into community treatment, by informing program targeting, screening, eligibility assessment, treatment, and monitoring.