[Homicide and major mental disorder: what are the social, clinical, and forensic differences between murderers with a major mental disorder and murderers without any mental disorder?].

OBJECTIVES: To establish the social, clinical, and forensic differences between murderers suffering from a major mental disorder and murderers without any psychiatric disorder and, in particular, to compare their respective records of psychiatric symptoms and their respective relationship with their victims.

METHOD: We studied 210 forensic examinations of murderers, the offences related to the murders, and the social and clinical information collected from psychiatric court reports on persons convicted of homicide. Firstly, we identified the socio-demographic, clinical and criminological profiles of 210 murderers from which were distinguished murderers with major mental disorder. Then, we compared the profiles of murderers suffering from a major mental disorder with those of murderers without any mental disease. In other words, we compared 37 persons affected with major mental disorder (schizophrenia, paranoiac delusional disorder, and affective disorder) with 73 persons without any mental disorder. We deliberately excluded subjects with personality disorder or abuse of/dependency on drugs, mental retardation or dementia.

RESULTS: With the exception of certain variables, murderers with major mental disorder have the same characteristics as others murderers: young man, living alone, with psychiatric and offence records and substance abuse. Murderers with major mental disorder are older (37.8 versus 31.7 years old) than perpretators without any mental disorder, and the former have a psychiatric record more often than the latter (81 versus 32.9%). In addition, contrary to the latter, the former show clinical symptoms of a psychopathological process. Depression, delusional and suicidal ideas are frequent among murderers with a major mental disorder, whereas the persons without mental disorder quarrel or have a row with their victim just before their crime. The victim was known to the perpetrator significantly more often in the major mental disorder group than in the no mental disorder group (94,6 versus 76,7%, p=0,008). The most major mental disorders' homicide was more likely to be against intimates than strangers. The application of the former article 64 or the present article 122-1 of the French Criminal Code are envisaged more often in the major mental disorder group than in the no mental disorder group.

CONCLUSION: The main difference between murderers with a major mental disorder and murderers without any mental disorder is the psychopathology of the morbid process which underlies the homicide. Impairment of judgment at the time of the crime should be taken into account. As a clinician, we should focus our attention on general risk factors of violence and homicide (male, young, underprivileged class, abuse of alcohol) and on more specific factors (mental disorder co-morbidities...). To these factors should be added the dynamic characteristics of the meeting of the protagonists.