Kyle MacDonald: How many mass shooters have mental health issues?

A teddy bear at a makeshift memorial in front of Marjory Stoneman Douglas High School in Florida.

Last week's horrific mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida set off what is now a sadly predictable flurry of public responses.

Thoughts and prayers, followed by calls for gun control, while the White House once more looked to blame "mental illness" for the tragic series of events.

But is the terrible trend of mass shootings and gun violence in the US associated with mental illness? Are the individuals who carry out these deeds mad, or just bad?

We're certainly told it's "crazy", in the colloquial sense of the word. It certainly is both hard to understand, and terrifying that young people would turn up to school and gun down fellow students and teachers. Common sense would have us believe they must be mad, right?

Common sense generally has a lot to answer for, and in this case, it is plain wrong.

Shootings like these are alarming and horrific, which also makes them newsworthy. We can't help but hear about them, indeed the whole world hears about them.

According to a report in Time magazine last year, the media plays a role too:

"Only about 4 per cent of interpersonal violence in the United States can be attributed to mental illness, the study authors conclude, yet close to 40 per cent of news stories about mental illness connect it to violent behaviour that harms other people."

This is stigma in action, plain and simple. Discrimination that is further propagated by government officials looking for a scapegoat to avoid talking about the real issue: gun control.

The American Psychiatric Association published a paper on mental illness and mass shootings last year and summarised all the available data.

Firstly, when we look specifically at mass shootings (defined by three or more victims), only 1 per cent of incidents involve a shooter with a serious mental illness. Less than 3 per cent of all gun-related homicides involve a shooter with a mental health history.

In fact, people with a mental health diagnosis are significantly less likely than the general population to commit any kind of violent crime, including gun-related homicide.

However, there is a link between guns, violence, and mental health - and one that no one talks about. Mental illness does, in fact, cause the majority of firearm deaths in the US: by suicide.

Where to get help:

• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• The Word
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.