On 25 October, Robert Card carried out America’s deadliest mass shooting of 2023 in Lewiston, Maine.

The Wednesday evening attack left 18 people dead and 13 wounded at a bowling alley and nearby bar, before the suspected gunman was found dead near a river 10 miles outside of Lewiston.

In the weeks that followed, news emerged that Card struggled with his mental health and was exhibiting aggression and paranoia in the lead-up to the shooting — and that his family warned law enforcement something needed to be done.

Amid a search for answers to explain the senseless atrocity — by those who knew Card, investigators, the Lewiston community and the public at large — came speculation that he may have suffered from a brain disorder called Chronic Traumatic Encephalopathy (CTE), caused by repetitive head trauma.

Personal accounts from those who knew him and interviews with experts suggest he may have sustained brain damage during his time in the military, according to a New York Times report. Two soldiers who served with Card also told the newspaper that army investigators have asked whether his time in the service could have altered his mental state.

Card’s brain is currently under examination by Boston University CTE Center to determine whether he had the disorder. A spokesperson told The Independent that the results won’t be available for six to eight months.

Psychiatric symptoms, such as paranoia, impulsivity and increased aggression have been observed in patients with confirmed or probable CTE, according to a peer-reviewed study from 2017. However, despite a widespread narrative that often correlates mental illness with violence, the data is clear: the vast majority of violence is not related to a perpetrator’s mental health.

The Independent spoke to experts about why this misconception persists, the effect of cases like Card’s and the broader fight to end a harmful stigma.

Understanding CTE

CTE is a type of brain damage caused by repeated head trauma — and it is 100 per cent preventable, Chris Nowinski, neuroscientist and CEO of The Concussion Legacy Foundation, told The Independent.

It is most often associated with people who play high-impact sports like football — and, increasingly, people who served in the military, as Card did. What makes CTE particularly difficult to understand is that it can’t be definitively diagnosed until an autopsy.

People with CTE typically experience progressive cognitive symptoms, Mr Nowinski said. Those symptoms include issues with executive functioning — such as issues following through on tasks — as well as short-term memory problems that can progress into larger memory problems.

In mid-life, patients may develop mental health symptoms, according to Mr Nowinski.

As the 2017 study suggests, CTE patients can develop paranoia and aggression, Mr Nowinski said, as Card purportedly did leading up to the Lewiston shooting.

However, the jury is still out on the exact relationship between CTE and psychiatric symptoms.

“What’s not as clear is if CTE pathology specifically is related to psychiatric symptoms or if it’s other aspects of traumatic brain injuries that have caused CTE that might be more associated with those behaviours — for example, long-term inflammation in the brain,” Mr Nowinski said.

Misperceived link between mental illness and violence

A widely cited, peer-reviewed study from 2015 indicated the vast majority of violent behaviour is caused by factors other than a mental health condition. In fact, the National Institute of Mental Health’s Epidemiologic Catchment Area survey found the risk of violence associated with serious mental illness alone to be 4 per cent, according to the study.

“Epidemiologic studies show that the large majority of people with serious mental illnesses are never violent,” the study reads.

The survey sought to debunk claims from “both sides” of the spectrum, according to the study. “The ECA study thus debunked claims on both extremes of the debate about violence and mental illness—from the stigma-busting advocates on the one side who insisted that mental illness had no intrinsic significant connection to violence at all, and from the fearmongers on the other side who asserted that the mentally ill are a dangerous menace and should be locked up; both views were wrong,” the study reads.

“The facts showed that people with serious mental illnesses are, indeed, somewhat more likely to commit violent acts than people who are not mentally ill, but the large majority are not violent toward others,” the authors continue.

Harold Kudler, an Associate Consulting Professor in the Department of Psychiatry and Behavioral Sciences at the Duke University School of Medicine, said the unfounded association between violence and mental illness creates a harmful stigma.

“They are our neighbours, our friends and our family members,” he continued. “It’s a terrible thing to see them isolated by myths and fear.”

Jeffrey Swanson, a professor of psychiatry and behavioural sciences at the Duke University School of Medicine and one of the authors of the 2015 study, told The Independent the association in part stems from people seeking an explanation for a horrific event.

“[Mass shootings] are so disturbing, so frightening, and so irrational, that we want to know why this happened,” he continued.

A spokesperson for the Boston University CTE Center told The Independent they’re hoping to do just that: give people answers in the wake of Card’s horrific violence.

“The reason further testing is being conducted on Mr. Card’s brain is that in an event such as this, people are left with more questions than answers,” the spokesperson said. “It is our belief that if we can conduct testing (in-house or outsourced) that may shed light on some of those answers, we have a responsibility to do that.”

While there are some instances where mental health symptoms can coalesce to increase people’s risk of violence — such as what many suspect to be Card’s case — the vast majority of people with mental illness are still never violent, according to Mr Swanson.

“It doesn’t mean that there aren’t cases where certain kinds of symptoms, like a combination of hostility, impulsivity, exacerbated threat perception…and substance intoxication will increase people’s relative risk of violence,” Mr Swanson said. “But all of the kinds of risk factors that we have to predict it are nonspecific, and they tend to apply to many more people who are not going to do the thing you’re trying to prevent.”

“It’s frustrating if you’re an advocate for better mental health care, and the only time you get to talk about it is when there’s a horrible mass shooting by somebody who’s really atypical of people with mental illness, as the vast majority will never do anything like that,” he added.

However, mental illness is “strongly associated” with an increased risk of death by suicide, according to the 2015 study. In 2021, death by suicide made up more than half of firearm-related fatalities in the United States.

Tangible solutions to curbing violence

As a result, to prevent the risk of violence and death by suicide, the study’s authors recommended “an emphasis on time-sensitive risk for violence or suicide” as the foundation of “evidence-based criteria for prohibiting firearms access.”

This policy is already in place in 21 states and Washington, DC. Dubbed “red flag” laws, they allow a judge to temporarily stop people from having guns if they could be a risk to themselves or others. While they differ state-by-state, they typically allow those close to the person in question to apply for an emergency order against them. If a judge approves it, they lose access to their firearms.

Mr Swanson said a key component of these laws is that, typically, the temporary removal does not carry a criminal penalty.

“It’s temporary, and it’s not criminalising, it doesn’t confer any kind of a criminal record or sanction,” he said.

Mr Swanson called these red flag policies a “great success.”

Meanwhile, Maine has a “yellow flag” law — the only one of its kind. The state passed it in 2020, just three years before the Lewiston shooting. After someone close to the person in question reports concerns about their behaviour, the police have to take them into protective custody. Police then can choose to ask a judge to temporarily halt the person’s access to firearms.

In the months leading up to the shooting, Card’s family and US military officials raised alarms about his increasing paranoia and aggressive behaviour. Yet, he was never taken into protective custody or given the mental health evaluation needed to trigger Maine’s yellow flag law, ABC News reported.

Supporting CTE patients

Much of Mr Nowinski’s work at The Concussion Legacy Foundation is focused on identifying resources for patients who may have CTE and their families. He said it’s essential to educate people about CTE because it can help prevent a disease that is 100 per cent avoidable.

Mr Kudler, who is an expert on veteran mental health care, says he’s an advocate for a model of care that integrates inpatient and outpatient mental healthcare systems, a method that is already used in the Veterans Affairs Healthcare system.

“The mental health system is divided into inpatient and outpatient systems, and they have different hierarchies,” Mr Kudler said. “But in VA, it is all integrated and then integrated again into primary care. It is as close to an ideal mental health system as exists in our country.”

For Mr Nowinski, educating people about CTE is a key factor in preventing it.

“We need to talk about it publicly,” he said. “And we need to talk about preventing it and making better choices.”

If you are experiencing feelings of distress, or are struggling to cope, you can speak to the Samaritans, in confidence, on 116 123 (UK and ROI), email jo@samaritans.org, or visit the Samaritans website to find details of your nearest branch.