Sports must address head trauma warning Stunned: The Dragons' Josh Miller after being hit. The rules of every Australian football code must be changed to address growing evidence that repeated head trauma increases the risk of dementia, a leading advocacy group has warned. A discussion paper reviewing the latest research about the impact of sport-related head injuries calls for a range of changes to the way sports handle players who are hurt, including a ban on speedy returns to the playing field by younger players. The NSW branch of Alzheimer's Australia bases its call on a wide-ranging review of research showing that those suffering head injuries had their risks of experiencing dementia increased two to four times. Representatives of the main football codes will attend a two-day conference on concussion in sport in Melbourne from Wednesday. The trauma identified in the paper, titled Football, Head Injuries and the Risk of Dementia, includes falls, head clashes, poor tackling, striking and heading the ball. "Football players may sustain concussive or subconcussive injuries throughout their playing career, with research suggesting this may increase their risk of developing dementia," the paper states. The paper asks all football codes to react to US research into the impact on sports players of chronic traumatic encephalopathy, a condition first known as being "punch drunk" that involves the progressive death of brain cells. Andrew Gardner, a clinical neuropsychologist, said the literature from the US suggested repeated concussions in the NFL led to changes in cognitive function. However, he said it was unknown whether the results translated to sports played in Australia. Dr Gardner - who has assessed several athletes with brain injuries - said symptoms included memory loss, slow processing and psycho-motor speed. The results often mimicked Parkinson's Disease. There's also been reporting of personality changes, people becoming short-tempered, aggressive, become reclusive or going into depression. We need to know if this is related to concussion or not. John Watkins, the chief executive of Alzheimer's Australia NSW, believes anecdotal evidence in Australia and US research demands football codes begin a comprehensive investigation of athletes suffering reduced cognitive function later in life. Mr Watkins is urging the codes to "co-operate fully in research." He said the bill could be shared between the codes and government. He said action was needed. He believes sports not only have a responsibility to care for participants but a failure to do so could lead to legal ramifications.