Violent criminal recidivism in mentally disordered offenders: a follow-up study of 13-20 years through different sanctions.

OBJECTIVE: To describe criminal recidivism, especially violent recidivism, in a long-term follow-up of mentally disordered offenders sentenced to different types of sanctions. SUBJECTS AND METHODS: A population-based Swedish cohort of male offenders referred to pre-trial psychiatric investigations between 1988 and 1995, was sentenced to forensic psychiatric treatment (n=163), prison (n=120), or noncustodial sanctions (n=52). They were followed from the beginning of their sanctions until the end of June, 2008, through official health and crime registers. Survival analyses were used to compare time until violent recidivism across different sanctions and mental disorders, and predictors of violent recidivism were investigated using univariate comparisons, a multivariate Cox regression analysis and Receiver Operating Characteristic (ROC) curves. Finally, all criminal reconvictions until the end of follow-up were assessed (a total time period of 13 to 20 years).
RESULTS: Forty-seven percent of all subjects were reconvicted for violent crimes during follow-up. There were no significant differences between sanction groups. By contrast, diagnostic groups that included substance abuse had significant effects, and stood out as the strongest predictor of violent reconvictions together with the number of previous violent crimes, and age at the first registered criminal offence. Variables identified in the multivariate model together predicted violent recidivism with an area under the ROC curve of 0.72, while the corresponding figure for the age at onset of criminality as the sole predictor was 0.71. Among the different sanction forms for different time periods, time in hospital and prison were significantly less associated with violent recidivism compared to time in conditional release/probation.