Mental illness and criminal behavior : individual characteristics related to criminal conduct among violent offenders with schizophrenia

Abstract

During the last decades, interest has increased in structured risk assessment of future violence as well as in research addressing the link between schizophrenia and violence. The overall aim of this study was to extend our knowledge concerning risk assessment and the connection between schizophrenia and criminal behavior. An additional aim was to replicate previous studies from North America in a Swedish socio-cultural context.

Method: This study comprised all male violent criminal offenders diagnosed with schizophrenia (N=272) subjected to a pre-sentence forensic psychiatric assessment for the first time between 1988 1995. The study had a retrospective design, where data on background, criminological characteristics and re-offending were obtained through registers and files. Predictive validity for various risk factors was estimated with logistic regression and receiver operating characteristic (ROC) analysis.

Results: A psychopathic personality disorder as measured by the Psychopathy Checklist - Revised (PCL-R) increased the risk for post-discharge violent re-offending. No other investigated risk factors yielded the same strong association to violent failure (Paper I). The historical part of the HCR-20 risk assessment instrument predicted violent recidivism in a short- (2 years) and a long-term (7 years) perspective. The Violence Risk Appraisal Guide predicted violent recidivism in the long- (7 years) but not in the short-term (2 years) perspective. The predictive accuracy as measured by ROC analysis increased over time (Papers II & III). Psychopathy was related to increased violent and non-violent criminality across different age intervals from adolescence to adult age. Substance abuse did not further increase crime rates above the level associated with psychopathy (Paper IV). Offenders with an early onset of criminal behavior differed significantly from those with a later onset in terms of adolescent behavior, adult social conditions, criminality and substance abuse (Paper V).

Conclusions The study suggests that psychopathy and historical risk factors should be more in focus when assessing risk for future violence among offenders with schizophrenia. The different trajectories into criminality suggested by the early/late starter typology might have implications for treatment.