Forty-year study of rates of homicide by people with schizophrenia and other homicides in the Chuvash Republic of the Russian Federation.

BACKGROUND: The extent to which rates of homicide by people with or without schizophrenia vary over time has theoretical and practical implications in understanding homicide by people with mental illness. AIMS: The aim was to report on the rates of homicide by people diagnosed with schizophrenia over time in a region in which there were dramatic changes in the overall rates of homicide. METHODS: An examination of homicide by people diagnosed with schizophrenia in the course of judicial psychiatric examination, and the rate of other homicide in the Chuvash Republic of the Russian Federation between 1981 and 2020 was undertaken. RESULTS: During the 40 years of the study a total of 5741 people faced legal proceedings for a homicide offence, of whom 179 (3.1%) were diagnosed with schizophrenia. During the study period the average annual total homicide rate rose from about 9 per 100 000 in the 1980s, peaked at 17 per 100 000 in the 1990s before falling to 13 per 100 000 in the 2000s and 6 per 100 000 in the 2010s. Rates of homicide by people with schizophrenia also rose and fell over this period and were significantly associated with the rates of other homicide (r = 0.503, d.f. = 38, P = 0.001). CONCLUSIONS: The rise and fall in rates of homicide by people diagnosed with schizophrenia in parallel to total homicide suggests that homicidal behaviour might not be intrinsic to the clinical manifestations of the illness, and might instead reflect a heightened vulnerability to social factors that are associated with homicide by people without schizophrenia.

Homicide and mental disorder in a region with a high homicide rate.

There are few studies of the relationship between mental disorder and homicide offences from regions with high rates of homicide. We examined the characteristics and psychiatric diagnoses of homicide offenders from the Chuvash Republic of the Russian Federation, a region of Russia with a high total homicide rate. In the 30 years between 1981 and 2010, 3414 homicide offenders were the subjected to pre-trial evaluations by experienced psychiatrists, almost half of whom (1596, 46.7%) met the international classification of diseases (ICD) 10 criteria for at least one mental disorder. The six most common individual diagnoses were alcohol dependence (15.9%), acquired organic mental disorder (7.3%), personality disorder (7.1%), schizophrenia (4.4%) and intellectual disability (3.6%). More than one disorder was found in 7.4% of offenders and alcohol dependence was the most frequently diagnosed co-morbid disorder. One in ten offenders were found to be not criminally responsible for their actions. Few homicides involved the use of substances other than alcohol, and firearms were used in 1.6% of homicides. The finding that people with mental disorders other than psychosis committed a high proportion of homicides in a region with a high rate of homicide, suggests that people with mental disorders are vulnerable to similar sociological factors to those that contribute to homicide offences by people who do not have mental disorder.

Characteristics of homicide offenders with Schizophrenia from the Russian Federation.

BACKGROUND: It has been suggested that the characteristics of homicides committed by people with schizophrenia from regions with a high total homicide rate differ from the characteristics of homicides by people with schizophrenia from regions with low rates of homicide. METHODS: Homicide offenders in the Chuvash Republic of the Russian Federation have been systematically examined for over 30 years. This study reports on a review of the documents from pre-trial psychiatric assessments and legal proceedings of all people charged with homicide offenses between 1981 and 2010 who were found to have schizophrenia. FINDINGS: There were 133 people (120 men, 13 women) with an ICD-10 diagnosis of schizophrenia who committed a homicide offense in the 30 years of the study, including 15 repeat homicide offenders and 9 homicides with multiple victims. The odds ratio (OR) for homicide associated with schizophrenia was 13.5, 95% confidence interval (CI) (11.4-16.0). The mean age of the offenders was 34.8 (SD 9.6) and most had the paranoid subtype of schizophrenia (78%). The majority of victims were family members (51%) or acquaintances (43%). Delusions of persecution, auditory hallucinations and other positive symptoms were present in 58% of offenders at the time of the homicide. The remaining 42% exhibited negative symptoms such as emotional deficits, had antisocial attitudes or were regarded as having impaired self-control. Alcohol intoxication was reported at the time of 45% of homicides. Stabbing was the most common method and few of the homicides involved firearms. CONCLUSION: The characteristics of homicide offenders with schizophrenia from Chuvashia do not appear to differ greatly from those of homicide offenders with schizophrenia from regions with far lower rates of homicide.