On April 16, 2007, 32-year-old Seung-Hui Cho killed 32 people on the Virginia Tech campus before committing suicide. It was the deadliest school shooting in United States history. Cho was diagnosed with severe anxiety disorder in childhood and found mentally ill by a court of law in 2005. Jeffery Dahmer is considered one of the worst serial killers in history. He committed acts of murder, rape, and cannibalism on 17 victims, and those are just the victims that we are aware of. Dahmer was found to be legally sane, but some have suggested that he may have been autistic. Ted Bundy was so eloquent as his own lawyer that the judge said he would be delighted to have him in his courtroom as counsel. Was he crazy? Did he know right from wrong? The unibomber, Ted Kaczynski, was determined to have a serious mental illness, but was criminally responsible for his actions. The more we learn, the more confused he becomes.

The first thing people want to do is make sure that people with severe mental illness can’t get guns. This is a good idea, but it doesn’t solve the problem of violent people who don’t have a mental illness.

The MacArthur Study of inpatient psychiatric patients found that mental illness alone is not an accurate predictor of future violence. In fact, the study found that someone diagnosed with schizophrenia is even less likely to be violent than the average person. The study found that the main risk factors for violence are: history of childhood abuse, previous arrests, antisocial personality disorder, parental drug abuse, substance abuse, anger management problems, violent fantasies, involuntary commitment to a mental hospital and even something as simple as being a young man. This is not to say that mental illness and violence are unrelated, or that those diagnosed with mental illness do not commit violent acts. However, those with mental illness who become violent tend to do so when they don’t take their medication, avoid treatment, and/or abuse substances. They also tend to have additional diagnoses on Axis II.

Every day, to determine who will have to stay in the hospital involuntarily, mental health professionals have to determine if a person is an imminent danger to themselves or to others. The research makes it clear that unaided clinical judgment in predicting future violence is little better than chance. Actuarial tools provide some improvement over clinical judgment, but how many hospitals, parole boards, prisons, jails, courts, and law enforcement agencies are using them in the US?

While the use of actuarial tools, such as PCL-R, VRAG, and STATIC 2000, are already commonplace in Canada, where most of these tools were developed, the trend is only now beginning to find its way into mental health and criminal justice programs. common US justice practices. It has to be universal. We can’t keep letting dangerous people out on the streets because we think they might not be. That should no longer be our standard of care. The clinical judgment to determine the risk of future dangerousness has an error rate of almost 50%. Actuarial tools have correct classification rates for hazard of 65-80. Our traditional psychological tests cannot be used in this way.

My own research on violence has shown that illness and psychiatric symptomatology alone are not enough to predict future violence. There is no simple construction. A combination of risk factors and the absence of resilience factors is needed to predict future violence. We run the risk of being too simplistic when we try to reduce violence to a single weakly related factor, such as mental illness. If a person with a mental illness stops taking their medication, has assaulted another person in the past, and begins abusing substances, they are at greater risk of future violence than a person with a mental illness without these characteristics. We have a wealth of tools at our disposal that will accurately assess the possibility of future violence, and we know the steps to handle it. Isn’t it about time we used these tools universally?