Studies on sex offenders have focused mainly on paraphilias, personality disorders, psychopathy and substance abuse but there has been little research into the links between psychosis and sex offending. A Danish study of 358,180 people (everyone born between 1944 and 1947) found that 2.2% of them had been hospitalized with psychosis. These men committed 8.4% of the physically aggressive sexual offences and 9% of the non-physically aggressive sexual offences committed by the men in the study. People with psychosis but not a personality disorder or a drug problem were no more likely to commit a violent sexual offence than other people but were three times more likely to commit a non-violent sexual offence. People who had psychosis and a personality disorder or a drug problem were six times more likely to commit a violent sex offence and three or five times more likely to commit a non-violent sex offence.
Alden, Amanda ... [et al] - Psychotic disorders and sex offending in a Danish birth cohort Archives of General Psychiatry November 2007, 64(11), 1251-1258