Objective: The authors examined psychiatric diagnoses of all individuals convicted of homicide and attempted homicide in Sweden from 1988 to 2001 (N=2,005).
Method: High-quality national crime and hospital registers were linked to investigate standardized psychiatric diagnoses of homicide offenders.
Results: The presence or absence of psychiatric diagnoses was ascertained for 1,625 (81%) of the homicide offenders; 1,464 (90%) of these offenders had a psychiatric diagnosis. Twenty percent (N=409) of all 2,005 offenders had a psychotic illness, and 54% (N=589) of a subgroup of 1,091 offenders with information on secondary diagnoses had a personality disorder as a principal or secondary diagnosis. Only 10% of the offenders for whom psychiatric diagnostic information was available had no diagnosis.
Conclusions: Using a comprehensive method for identifying psychiatric illness in homicide offenders, the authors found higher rates of psychiatric morbidity than previous studies. Their findings underline the importance of psychiatric assessment in homicide offenders and suggest that treatment might have a preventive role.