Editor:
There are a modest number of published studies of homicide followed by the suicide of the offender (homicide-suicide), perhaps because of the intrinsic difficulty in studying the motives of an offender who has died. Hence, the recent review by Eliason1 of 16 studies is a useful addition to the literature. However, our systematic review of the epidemiology of homicide-suicide2 reached a different conclusion from those of Eliason and two earlier reviews.3,4 Instead of finding a relatively fixed rate of homicide-suicide, we found a 100-fold variation between the lowest rate and the highest rate in the 65 samples of homicide-suicide located by using exhaustive search strategies. The earlier reviews also concluded that the rate of homicide-suicide is unrelated to that of other homicides. However, we found a strong association between rates of homicide and homicide-suicide in the United States, which has high rates of both. In addition, we analyzed a subset of 18 studies reporting firearm use in homicide-suicide with a finding that supports Eliason's conclusions about the significance of guns in these events.
Similarly, the belief that the rate of homicide by the mentally ill does not vary significantly between regions, or over time, is not supported by the evidence. We re-examined with updated samples the data used by Coid3 and Taylor and Gunn5 and found a strong association between rates of homicide by people with schizophrenia and total homicides6 and a significant rise and fall in the rates of homicide by the mentally ill in the United Kingdom.7 The presence of wide variations in both the rates of homicides and homicide-suicide committed by the mentally ill demonstrates the need to examine not only illness variables but also the importance of societal factors associated with these tragic events.
Footnotes
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Disclosures of financial or other potential conflicts of interest: None.
- American Academy of Psychiatry and the Law
References
Reply
Editor:
Drs. Large, Nielssen, and Smith1 have brought forth several important concerns on the subject of homicide-suicide. They assert that the rate of homicide-suicide is not fixed and that the rate can be related to the rate of homicide alone. In their recently published paper, they report a variation of rate from 0.137 events per 100,000 in countries outside the United States to 0.313 per 100,000 within the United States. These statistics show a 2.5 times higher rate of homicide-suicide in the United States than in other countries. Although this is a greater incidence, homicide-suicide is still a relatively rare event that occurs at a rate lower than 1 per 100,000. They presented compelling evidence that the homicide-suicide rate may be related to the rate of homicide alone in areas with higher homicide rates such as the United States.
There is also some discrepancy in the definition of murder-suicide and the amount of time between the two events for them to qualify as a murder-suicide. In my review,2 murder-suicide was defined as a homicide that was followed by a suicide within one week, but Large et al. defined it as any homicide followed by a suicide before conviction.
As Large et al. point out in their letter and recently published paper, there are very few publications and studies on murder-suicide. Their recent publication is a helpful addition to the literature.
Footnotes
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Disclosures of financial or other potential conflicts of interest: None.
