Prevalence of Serious Mental Illness Among Jail Inmates

Abstract

OBJECTIVE: This study estimated current prevalence rates of serious mental illness among adult male and female inmates in five jails during two time periods (four jails in each period). METHODS: During two data collection phases (2002-2003 and 2005-2006), recently admitted inmates at two jails in Maryland and three jails in New York were selected to receive the Structured Clinical Interview for DSM-IV (SCID). Selection was based on systematic sampling of data from a brief screen for symptoms of mental illness that was used at admission for all inmates. The SCID was administered to a total of 822 inmates-358 during phase I and 464 during phase II. To determine the current (past-month) prevalence of serious mental illness (defined as major depressive disorder; depressive disorder not otherwise specified; bipolar disorder I, II, and not otherwise specified; schizophrenia spectrum disorder; schizoaffective disorder; schizophreniform disorder; brief psychotic disorder; delusional disorder; and psychotic disorder not otherwise specified), interview data were weighted against strata constructed from the screening samples for male and female inmates by jail and study phase. RESULTS: Across jails and study phases the rate of current serious mental illness for male inmates was 14.5% (asymmetric 95% confidence interval [CI]=11.0%-18.9%) and for female inmates it was 31.0% (asymmetric CI=21.7%-42.1%). CONCLUSIONS: The estimates in this study have profound implications in terms of resource allocation for treatment in jails and in community-based settings for individuals with mental illness who are involved in the justice system.