First New Zealand professional rugby union player confirmed to have died with CTE

A former professional rugby union player, who who died in 2023 at the age of 33, has become the first in New Zealand to be formally diagnosed with chronic traumatic encephalopathy (CTE) – the neurogenerative disease associated with repeated head trauma.

Billy Guyton died of a suspected suicide last year, CNN affiliate Radio New Zealand (RNZ) reported, and his family subsequently donated his brain to Auckland’s Neurological Foundation Human Brain Bank which made the CTE diagnosis.

CTE can only be formally diagnosed after death with an autopsy. It is pathologically marked by an abnormal buildup of a protein called Tau in the brain which can disable neuropathways and has been associated with a variety of clinical symptoms, including memory loss, confusion, impaired judgement, aggression, depression, anxiety, impulse control issues and sometimes suicidal behavior.

The Auckland Brain Bank told CNN in a statement on Monday that its co-director Professor Maurice Curtis had been “working closely with the family of Billy Guyton to interpret the results of a post-mortem pathology undertaken of Billy’s brain.”

It added that it doesn’t normally share the details of a donor’s pathology but that the family had granted permission to comment in this case.

Guyton’s father, John, told RNZ that his son’s death came after years of “cries for help.”

“I figured out Billy had CTE a few days after he died,” he said. “My wife and I were watching a documentary on it, and I said … that’s Billy. That’s what he had.’

“If I can work it out based on a documentary, what the hell were all those specialists Billy saw missing?”

After playing for three Super Rugby franchises – the top-flight league in New Zealand and Australia – Guyton retired from rugby in 2018 aged 28, telling the Nelson Weekly that concussion symptoms had forced his hand. CNN has contacted New Zealand Rugby for comment.

“The poor guy would spend hours in a small, dark cupboard because he couldn’t handle being in the light,” John Guyton told RNZ. “Some mornings he’d just sit in the bottom of his shower tray crying, trying to muster up the energy to get moving.

“Can you imagine what was going on in that guy’s head?”

Associate Professor Michael Buckland, founder and director of the Australian Sports Brain Bank, confirmed the CTE diagnosis, and categorized it as stage 2 of the disease on the four-step scale assessing its severity.

Stage 2 of the disease is characterized by “multiple collections of Tau protein in the furrows of the cerebral cortex, which is the external layer of the brain,” the Auckland Brain Bank said, while by Stage 4 “it is widespread across several regions of the brain.”

Professor Curtis added that “there are a limited number of modifiable risk factors in this case, and concussions and head knocks are certainly one of them.”

Guyton’s diagnosis further spotlights the sport’s growing head injury crisis.

Around the world, players are grappling to deal with the impact of head injuries sustained during their rugby careers.

In the UK, some 450 current and former rugby players have now joined lawsuits to take legal action against global governing body World Rugby and the national governing bodies of England and Wales, the Rugby Football Union (RFU) and the Welsh Rugby Union (WRU), Rugby Football League Limited, International Rugby League Limited and British Amateur Rugby League Association.

Lawyers for the plaintiffs say there was a failure to protect them from permanent injury caused by repeated head injuries and concussions during their careers.

A new study from the University of Glasgow, Boston University and the University of Sydney which looked at the post-mortem brain exams of 31 former amateur and elite rugby union players found CTE in 68% of the brains, which had been donated for research purposes.

There is a potential bias in these numbers because the brains donated were probably submitted by relatives who noticed these symptoms in their family members when they were living.

CNN’s Amy Woodyatt contributed to this report.

Editor’s Note: If you or someone you know is struggling or in crisis, help is available.

If you live in the US and are having suicidal thoughts, call or text 988 or chat at 988lifeline.org.

TrevorLifeline, a suicide prevention counseling service for the LGBTQ community, can be reached at 866-488-7386.

Befrienders Worldwide connects users to the nearest emotional support center for the part of the world they live in.