MEZ

"Ice hockey players with longer careers not only were more likely to have CTE, but they also had more severe disease," explains corresponding author Jesse Mez, MD, MS, co-director of clinical research at the CTE Center and associate professor of neurology at Boston University Chobanian & Avedisian School of Medicine.

"Enforcers have dominated the CTE conversation, but our findings provide the most evidence for the cumulative amount of play as the predominant risk factor for CTE," says Mez.

"This appears to be a case where together these risk factors add up to a greater risk for aggression than they each do on their own, where people with CTE and a family history of mental illness are much more likely to have aggressive behavior than those with just CTE or just the family history," said study author Jesse Mez, MD, MS, of Boston University Chobanian & Avedisian School of Medicine and a member of the American Academy of Neurology.

"This relationship was most striking for participants who died between 40 and 59 years old," Mez added.

"The link between a family history of mental illness and aggression may be through a shared genetic background and also through shared environment and common behaviors, such as childhood experiences with family members," said Mez.