(July 23, 2013) A new study from Australia reports that individuals with schizophrenia – even those who do not have substance abuse problems – are significantly more violent than the general population. The violent behavior of these individuals is directed disproportionately against family members.
The study compares violent behavior in 8,809 individuals with and without schizophrenia in the state of Victoria, Australia, a state of 5.5 million people that includes Melbourne.*
Overall, 25% of individuals with schizophrenia were charged with a criminal offense during their lifetime, compared with 10% of the community control (general population) sample. Specifically for violent offenses, 2.4% of the community control sample was found guilty of a violent offense whereas 6.4% of those with only schizophrenia were found guilty of a violent offense, and 22.8% of those with schizophrenia plus substance abuse were found guilty of a violent offense.
Thus, schizophrenia alone increased the chances of violent behavior by 2.7 times, but schizophrenia plus substance abuse increased the chances of violent behavior by 9.5 times.
The research refutes the often-cited but now largely discredited MacArthur Violence Risk Assessment Study that reported individuals with schizophrenia but no substance abuse were no more violent than the general population.
The “general population” used in the MacArthur study was one with a high incidence of violent behavior. As a result, the excess violent behavior among individuals with schizophrenia is found only among individuals with schizophrenia who also have substance abuse problems. The MacArthur conclusion is at odds with several other studies, including this one from Australia, which affirms that individuals with schizophrenia, if they are not being treated, are as a group more violent than the general population.
Other studies have shown that treatment is the key issue: Individuals with schizophrenia who are being treated are not more violent than the general population.
Two other findings are noteworthy from this study.
First, the increase in violent behavior was much more marked among women than among men. Men are known to have a propensity to violent behavior with or without schizophrenia. Women are less prone to violent behavior unless they have schizophrenia. Second, a disproportionate amount of the violent behavior by individuals with schizophrenia was directed at family members in this study.
Both of these findings are consistent with the findings from several other studies.
* The study included 4,168 individuals with schizophrenia and 4,641 control individuals who did not have schizophrenia. Read the full study here .
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