The doctor who first investigated a link between dementia and football has warned that the authorities are becoming trapped “in a cycle of research” and urged immediate action to protect players, particularly children, from the risk of devastating brain injury.

Dr Don Williams, a consultant psychiatrist, began looking into the impact of heading and repetitive brain trauma in football almost 40 years ago after meeting a patient with early onset dementia following a long playing career. He instigated groundbreaking research by tracking 14 former players with dementia who were referred to his Old Age Psychiatry Service in Swansea between 1980 and 2003.

Chronic traumatic encephalopathy – a type of dementia associated with head trauma and sports such as boxing and American football – was found in two-thirds of the brains that were ultimately examined in post-mortem. It was the first time that CTE had been confirmed in a group of former footballers. That research was published in 2017 and followed the CTE diagnosis in Jeff Astle, the former England striker who died in 2002. CTE was also found last year in the former Portsmouth wing-half Rod Taylor and the Jeff Astle Foundation has been contacted by the families of more than 400 former players with dementia.

The issue has been brought into particular focus over this past fortnight following the deaths in their seventies of two iconic British centre-backs – Billy McNeill and Tommy Smith – who had been living with dementia.

The Football Association and the Professional Footballers’ Association are jointly funding research into the prevalence of dementia in former players but, with that study only starting last year, Williams is calling on the authorities to be more proactive. Rather than cite the lack of absolute proof, he believes that there is already sufficient evidence for the “precautionary principle” to be applied. “This principle is important in public health and asserts that when there is scientific uncertainty about a controversial matter, the way forward must be decided by erring on the side of caution,” he said.

“I have seen at first hand the devastation caused by dementing illnesses, not only for the individual but for family members. Dementia in footballers is an industrial disease. It is time to start the process of prevention. I feel frustrated that nothing has happened.

“Heading the ball in children under 11 should be banned, as it is in the United States, and curtailing this component of the game among adults must start. Players at risk should also be screened regularly to detect the emergence of brain damage.

“They could perform cognitive tests and look for possible alterations to the structure of the brain and have a more informed discussion about the pros and cons of early retirement. I would also like to see a campaign of awareness and for more of football’s vast resources to be channelled into a fund to ensure ex-players receive high-quality care and their relatives are plugged into an effective support network.”

Williams, who has worked with dementia patients since 1974 and was previously involved in the campaign against smoking, first began to consider the potential dangers in football when he met Roger Thomas in 1981, whose father, Wilfred, had dementia. Wilfred had played for Brighton, Swansea Town and various representative sides.

“He asked if there could be a link – he said that his father could head a ball further than he could kick it,” said Williams. “The more I thought about it, the more I became convinced. The brain is a very delicate and fragile organ.”

Roger Thomas says that his father once even scored a goal from inside his own half with his head and, as he witnessed his deterioration, he thought of the comparison to boxing.

Williams has since also been in touch with the family of Trevor Ford, the former Wales striker who became the most expensive player in British history when he moved from Aston Villa to Sunderland for £30,000 in 1950. Ford began to show symptoms of dementia around the age of 70 and died in 2003. His son, David, now says “there is no doubt” his father’s dementia was linked to football.

“He was a very robust centre-forward,” he said. “There needs to be much greater awareness and responsibility around this issue. It is the families who ultimately suffer.”

The players who formed part of Williams’s study were examined at the University College London’s Institute of Neurology in research funded by the Drake Foundation.

A separate study by the University of Glasgow, which is led by Dr Willie Stewart, has found CTE in around 75 per cent of the donated brains of former football and rugby players with dementia. The findings compare with a CTE prevalence of around 12 per cent in the brains of people with dementia in the general population.