Interpreting Risk Factors for Violence in Australia

To the Editor: We commend Dr. Nielssen and colleagues (1) on their thoughtful study of risk factors for homicide and other violence in first-episode psychosis that appeared in the July issue. This research adds to a considerable body of work highlighting the need for early intervention services and comprehensive treatment and support for persons with severe mental illness.

However, given the extremely small sample associated with firearms misuse (16 out of 272 cases between 1992 and 2008), we suggest that general conclusions about the availability of means are somewhat premature. We must also correct the assertion that Australia's 1996 gun laws were followed by a steady decline in the use of firearms in homicide and suicide. This claim, based in part on now-discredited work (2), overlooks the fact that homicides and suicides by firearm were both declining well before the contentious and highly politicized legislative changes occurred. Several recent studies have shown that the legislative changes did not have a significant impact on the preexisting downward trend in firearm homicide in Australia (3). Method substitution and concurrent declines in suicide by means other than firearms, along with the introduction of national suicide prevention programs, preclude drawing firm conclusions about the impact of the laws on suicide by firearm (4).

Although these observations should certainly not detract from the work of Dr. Nielssen and his colleagues, they do provide a strong caution against inferring that Australia's gun laws have played any significant role in reducing the incidence of lethal violence (to self or others). The costs of administering the legislation are estimated to range between $27 and $100 million per year—or between $405 million and $1.5 billion over the 15 years since they were implemented (5). This leads inevitably to speculation on what gains could be achieved if that funding was instead directed toward early intervention and ongoing support for vulnerable Australians living with mental illness.