ABSTRACT
Prevalence rates of major mental disorders (MDs) among offenders vary depending on the definition of MD adopted, the time frame applied and the population examined. Estimates range from a low of 15% (Magaletta, Diamond, Faust, Daggett, & Camp, 2009) to as high as 80% when personality and substance abuse disorders are included (Brink, 2005; Brink, Doherty, & Boer, 2001). Some of the highest rates have been found in the federal Canadian correctional system (Beaudette, Power, & Stewart, 2013; Brink et al., 2001; Motiuk & Porporino, 1991). Offenders with major mental disorders, then, can constitute a significant proportion of the offender population, posing a challenge for those mandated to provide the specialized services many require. Moreover, there is consistent evidence across constituencies that the rates of MD in offender populations have been increasing, although the reason for this is less clear (Diamond, Wang, Holzer, Thomas, & Cruser, 2001). Deinstitutionalization has been implicated in the increase (Ogloff, 2002), but at least one study failed to confirm the link between closure of psychiatric inpatient beds and increases in rates of MD in prison in the time period
from the 1960s to the 1980s (Steadman, Monahan, Duffee, Hartstone, & Robbins, 1984).
