A Review of the Prevalence of Psychosis in Sexual Homicide.

Despite a growing body of research on the association between psychosis and homicide and between psychosis and sexual offending, research on psychosis and sexual homicide is limited. The objective of this review was to estimate the prevalence of psychosis in sexual homicide and to explore the extent to which prior research has investigated symptoms of psychosis as a motivating or causal variable leading to incidents of sexual homicide. We hypothesized that psychosis is present in a minority of sexual homicide cases. Articles were identified by searching literature databases (i.e., PsycINFO, MEDLINE, EMBASE) and references of relevant articles. Eight studies were included. The overall prevalence of psychosis among individuals who committed sexual homicide ranged from 0 to 27 percent as measured in a broad array of diverse samples. Given that five of the eight studies reported psychosis rates to be five percent or less, our findings suggest that psychosis occurs in a minority of sexual homicide cases. None of the studies directly examined the causal or motivational properties of psychosis in driving these types of offenses, and this represents an important area of inquiry for future research.