Clinical Research Unit for Anxiety and Depression, St Vincent’s Hospital, Sydney, NSW, Australia.
Schizophr Bull. 2011 May;37(3):572-9. doi: 10.1093/schbul/sbp112. Epub 2009 Oct 12.
The homicide of strangers by people with psychosis, referred to here as "stranger homicides," are rare and tragic events that generate adverse publicity for mental health services and have resulted in significant changes in mental health policy and law.
To estimate the incidence of stranger homicides, using data from previously published studies, and to compare the characteristics of psychotic offenders who killed strangers with the characteristics of those who killed a close relative.
Meta-analysis of the population-based studies of homicide by persons suffering from a psychosis in which the number of subjects who killed strangers was also reported. Characteristics of stranger homicide and family homicide offenders were examined in a multicenter case-control study of homicide during psychotic illness in four high-income countries.
A pooled estimate of 1 stranger homicide per 14.3 million people per year (95% confidence interval, 1 in 18.9 million to 1 in 11.5 million people per year) was calculated by meta-analysis of 7 studies. The characteristics of the 42 stranger homicide offenders from New South Wales [NSW], Quebec and Eastern Ontario, Finland, and the Netherlands were identified. Twenty seven (64%) of these had never previously received treatment with antipsychotic medication. The stranger homicide offenders were more likely to be homeless, have exhibited antisocial conduct, and had fewer negative symptoms than those who killed family members. The victims of stranger homicide were mostly adult males and the homicides rarely occurred in the victim's home or workplace.
Stranger homicide in psychosis is extremely rare and is even rarer for a patient who has received treatment with antipsychotic medication. A lack of distinguishing characteristics of stranger homicide offenders and an extremely low base rate of stranger-homicide suggests that risk assessment of patients known to have a psychotic illness will be of little assistance in the prevention of stranger homicides.
精神病人杀害陌生人的事件，即“陌生人凶杀案”，极为罕见且后果悲惨，此类事件会给精神卫生服务带来负面宣传，导致精神卫生政策和法律发生重大变化。
使用先前发表的研究数据来估算陌生人凶杀案的发病率，并比较杀害陌生人的精神病患者与杀害近亲的精神病患者的特征。
对患有精神病的人实施的凶杀案进行了基于人群的研究的荟萃分析，其中还报告了有多少人杀害了陌生人。在四个高收入国家的精神疾病期间凶杀的多中心病例对照研究中，研究人员对陌生人凶杀和家庭凶杀犯的特征进行了检查。
通过对 7 项研究的荟萃分析，计算出每年每 1430 万人中有 1 例陌生人凶杀案（95%置信区间，每年每 1890 万人中有 1 例至每 1150 万人中有 1 例）。确定了来自新南威尔士州[NSW]、魁北克和安大略东部、芬兰和荷兰的 42 名陌生人凶杀犯的特征。其中 27 名（64%）从未接受过抗精神病药物治疗。与杀害家庭成员的凶手相比，陌生人凶杀犯更有可能无家可归、表现出反社会行为，且负面症状更少。陌生人凶杀案的受害者大多是成年男性，凶杀案很少发生在受害者的家中或工作场所。
精神病人实施的陌生人凶杀案极为罕见，而接受过抗精神病药物治疗的患者实施陌生人凶杀案的情况更为罕见。由于缺乏陌生人凶杀犯的特征，且陌生人凶杀案的发生率极低，因此，对已知患有精神病的患者进行风险评估，对于预防陌生人凶杀案几乎没有帮助。
