Diagnostic prevalence and comorbidity

Abstract Prisons and jails remain a growth industry, with many countries having increased correctional services to cope with an ever-burgeoning population. One long-standing issue is the perceived increase in the prevalence of mental disorders that are found in correctional settings compared to the community. Definitions of mental disorders and methods of case ascertainment vary substantially. That said, the available data now reflect some consistencies in the range of estimated prevalence reported. The rates of almost all mental disorders are several times higher than those found in the general community, and rates of comorbidity are exceptionally high. This chapter outlines the best available correctional prevalence of common mental disorders and considers the key assumptions and methodological challenges around ascertaining rates of these different diagnoses.