Psychiatric aspects of homicide.

Homicide is frequently associated with mental illness and suicide. The present study is an investigation of all known homicide incidents in Iceland during the past 80 years (1900-1979). There were 45 homicide incidents, involving 52 victims and 47 offenders. One-third of the perpetrators were either psychotic, mentally subnormal, or committed suicide. A further one-third were diagnosed as personality disordered, alcoholic, drug dependent or neurotic. A substantial proportion of the offenders suffered from fairly marked physical disabilities, and the mentally ill were significantly more frequently afflicted by such defects. Over 60% of the offenders and 50% of the victims were under the influence of alcohol at the material time. The findings are generally consistent with those of previous psychiatric studies of homicide.