Mass Shootings and Mental Health

Written by Alex Jensen



On February 14, 2018, fourteen students and three staff members at Marjory Stoneman Douglas High School in Parkland, Florida lost their lives in the deadliest school shooting since Sandy Hook in 2012. Over the course of about five minutes, the sole gunman, armed with smoke grenades and a Smith & Wesson M&P15, indiscriminately shot students, teachers, coaches, and administrators. The suspected perpetrator, nineteen-year-old Nikolas Kruz, was apprehended by police later that afternoon and has since confessed to committing the shootings.


The day after the tragedy, President Donald Trump tweeted that there were “[s]o many signs that the Florida shooter was mentally disturbed,” urging the American people to “always report such instances to authorities, again and again!” In an address to the nation that same day, Trump vowed to “tackle the difficult issue of mental health.” House Speaker Paul Ryan spoke similarly in the wake of the shooting, alleging that “mental health is often a big problem underlying these tragedies.”


In attributing the shooting in Parkland, Florida to the mental health of its suspected perpetrator, Trump and Ryan seem to be in agreement with much of the American public, nearly half of which, according to a 2013 Gallup poll, lay “a great deal” of the blame for mass shootings on the failure of the mental health system. Mental health, in the reckoning of much of the American public and its political representatives, bears more responsibility for mass shootings than any other factor, including the accessibility of firearms, the prevalence of drug abuse, and the spread of extremist ideology through digital media.


But to what extent can mass shootings – and violent crime more generally – be attributed to mental health disorders? While it is true that those with serious mental illnesses are three to four times more likely to commit a violent crime than those with no such illnesses, the vast majority of those with mental illnesses will never commit a violent crime. Indeed, only about a quarter of mass shootings, and only 4% of violent crimes in general, are committed by those who have been diagnosed with a mental illness, usually schizophrenia or bipolar disorder. In fact, those with mental health disorders are far more likely to be the victims of violent crimes – twelve times more likely than the average American – than the perpetrators.


Moreover, even what has been said so far can be misleading: the relationship between mental illness and violence does not seem to be a directly causal one. Though mentally ill people may be more likely to commit violent crimes, studies suggest that this is due, not to mental illness itself, but to other factors associated with mental illness. A 2002 study, for instance, found that those with mental illnesses who have no prior history of childhood victimization or substance abuse were in fact less likely than the general population to commit a violent crime. What these studies seems to suggest, then, is that the reason those with mental illnesses are more likely to commit violent crimes is not because mental illness causes violence but rather because mental illness is associated with other factors – such as childhood victimization and substance abuse – that do play a causal role in violent crime.


In the case of Nikolas Kruz, we do know from Florida state investigators that he was diagnosed with depression, autism, and ADHD, but, as of yet, there is no evidence that he was diagnosed with the kind or severity of mental illness (e.g. bipolar, schizophrenia, major depression) that would have posed a risk factor in his committing a violent crime. Indeed, being a male, having a history of relationship violence, obsessing over firearms, and holding right-wing extremist political views are all better indicators of one’s likelihood to commit a violent crime than a mental health diagnosis, and Kruz exhibited each one of these indicators. Thus, to single out mental health as a “big problem” underlying mass shootings serves only to further stigmatize those suffering from mental illness and surreptitiously remove from view the real factors behind violent crime and mass shootings that we should be talking about.