The applicability of the results of these studies to the United States is questionable because of the historically higher base rate of homicide in the United States and differences in the social and demographic composition between the United States and other countries. U.S. studies have examined rates of mental illness among incarcerated individuals but have not generally provided prevalence rates by offense. The prevalence of current psychotic symptoms among individuals in criminal justice facilities has been estimated to be between 9% and 24% (with higher rates among female inmates and among jail inmates as opposed to prison inmates), and the prevalence of any psychiatric problem has been found to be as high as 91% (9-12). About 68% of inmates are reported to have a substance use disorder (13).