• Posted December 2, 2024

CTE Plus Family History of Mental Illness Raises Odds for Aggression

Concussion-related brain damage can combine with a family history of mental illness to make some athletes and military personnel prone to aggression and violence in middle age, a new study says. 

People with chronic traumatic encephalopathy (CTE) are at higher risk of mood changes and dementia, but this study shows that aggression is another risk posed by the condition.

“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,” researcher Dr. Jesse Mez, an associate professor of neurology with the Boston University Chobanian & Avedisian School of Medicine, said in a news release.

Some individual cases have already highlighted the potential link between CTE and violence.

For example, former New England Patriots tight end Aaron Hernandez hanged himself in jail at age 27 following his conviction for the murder of a friend. Autopsy of his brain revealed it was riddled with CTE damage, particularly in regions associated with decision-making and judgment.

In this study, researchers looked at 845 men exposed to repetitive head impacts through contact sports or military service, including 329 who played professional football. All donated their brains to research after death.

About 70% had CTE, and 45% had a family history of mental illness, researchers said.

The research team interviewed family about each man’s aggressive behavior, and whether any close relatives had ever been diagnosed with major depression, bipolar disorder, anxiety, PTSD, obsessive-compulsive disorder, or any other mood or mental illnesses.

Results show that men with CTE and a family history of mental illness were more likely to get into arguments or physical fights with other people.

“This relationship was most striking for participants who died between 40 and 59 years old,” Mez said.

The association held even after accounting for other risk factors, such as their total years playing contact sports or serving in the military, researchers said.

However, people without CTE did not have an increased risk of aggressive behavior, even if they had a family history of mental illness,

“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,” Mez said. 

“Identifying people who are more likely to show symptoms of aggression based on family history of mental illness would give us a way to predict the consequences of CTE and identify who may benefit most from treatment options,” he added.

The new study was published Nov. 27 in the journal Neurology.

More information

The Concussion Legacy Foundation has more on CTE.

SOURCE: American Academy of Neurology, news release, Nov. 27, 2024