Arrest trajectories of adults with a serious mental illness

Objective: The objective was to identify subgroups of individuals with a serious mental illness (SMI) with different patterns of arrest, and to assess differences in the characteristics of individuals in these groups.

Method: We used multiple administrative data sets to identify adults with a SMI arrested in a large urban county in FY 03-04 and followed them for 1 year prior and 2 years following the 7/1/03-6/30/04 period. We used latent class growth analysis to identify subgroups with similar arrest patterns and multinomial logistic regression to assess differences in participant characteristics across the groups.

Results: We identified three subgroups: 1) one with little or no recidivism beyond the index year, 2) another with a consistent arrest pattern of about one-half arrest per year, and 3) a third group averaging just over four arrests per year. Compared with participants with low/no recidivism, those with some and high recidivism were more likely to be relatively young, male, homeless, and with fewer outpatient and more emergency room/inpatient mental health contacts. Participants with the highest recidivism were also more likely to have a psychotic disorder as opposed to bipolar I disorder and be substance abusers, whereas those with some recidivism were least likely to have undergone an involuntary psychiatric examination.

Conclusions: Identification of subpopulations with different risks of arrests over time provides useful information to policy makers regarding the differential targeting of resources designed to reduce the risk of arrest and increase treatment access.