(June 5, 2018) The connection between violence and mental illness is seen in headlines almost every day in the United States and throughout the world, often when trying to explain inexplicable acts of mass violence.
Although a very small proportion of individuals with serious mental illness who are untreated may exhibit violent behaviors or commit violent acts, individuals with serious mental illness are more often the subjects of crimes not the perpetrators. New research utilizing the Danish National Registry and police data in Denmark brings first-of-its-kind evidence to the risk of being subjected to crime for individuals with mental illness, published last month in JAMA Psychiatry. Jeffrey Swanson, PhD, arguably the most-renowned expert in serious mental illness in violence, published a piece in the same periodical on how the results of the Danish study compare to the United States.
Using longitudinal data of more than two million individuals and multiple independent variables, the Danish study found that individuals with mental illness are at 2.5 times higher risk of being subjected to any crime compared to the general population, and at even higher risk of being subjected to violent crimes.
The authors found that the risk of being subjected to crime varies depending on mental illness diagnosis, sex and the individual's own history of crime.
For example, women are at significantly higher risk of being a subject of a crime compared to men with the same illnesses, and individuals with serious mental illness such as schizophrenia or bipolar disorder were at greater risk than other mental illnesses. An individual's risk of being victimized increases if the individual also has a history of their own criminal offending, which the authors argue is due to similar risk factors for both being arrested for offenses as well as being victimized.
Violence and victimization in the United States
In his editorial on the piece, Swanson points out the important differences between the two countries and how these may explain some of the causal mechanisms behind victimization and mental illness. A 2005 study conducted in the United States found that individuals with mental illness are at 12 times greater risk of being a subject of a crime, compared to the 2.5 times greater risk in the Denmark study. This suggests that individuals with mental illness in the United States are at a disproportionately greater risk for victimization, which raises important considerations as to what might make people with mental illness more vulnerable to crime.
"Compared with Denmark, the United States has more of the factors that increase crime (such as poverty and inequality) and less of the factors that might ameliorate it (such as a strong social safety net and universal health insurance)," argues Swanson. An environment in which crime vulnerability increases when mental illness and poverty occur together suggests the importance of supportive resources for mental illness treatment and recovery and overcoming poverty is essential to reverse this association.
Swanson ends the piece by reiterating the Danish authors' call for more research into the relationship between mental illness and becoming a victim of a crime but argues "a larger lesson from their findings is that things could be worse in Denmark; certain other countries might do well to follow their example."
Elizabeth Sinclair
Director of Research
References:
- Dean, K., et al. (2018). Risk of being subjected to crime, including violent crime, after onset of mental illness: A Danish National Register study using police data. JAMA Psychiatry.
- Swanson, J., & Belden, C. M. (2018). The link between mental illness and being subject to crime in Denmark vs the United States: How much does poverty and the safety net matter? JAMA Psychiatry.