One in Three Former NFL Players Believe They Have CTE

About a third of former National Football League (NFL) players believed they had chronic traumatic encephalopathy (CTE), survey data suggested.

Among former NFL athletes who volunteered to complete a questionnaire, 34.4% said they perceived they had CTE, according to Rachel Grashow, PhD, MS, of the Harvard T.H. Chan School of Public Health in Boston, and co-authors.

Men with perceived CTE were more likely to have health problems associated with cognitive impairment than those without perceived CTE. Suicidality was reported by 25.4% of former players with perceived CTE and 5.0% of those without perceived CTE.

After adjusting for depression and other variables, men with perceived CTE were twice as likely to report suicidality (OR 2.06, 95% CI 1.36-3.12, P<0.001), the researchers reported in JAMA Neurology.

CTE is an autopsy-based diagnosis defined by tau deposition patterns seen in some American football players.

“This study was not designed to look at CTE, since living players have no way of knowing whether or not they have that neuropathology, but to look for patterns among those who believe they have CTE,” Grashow said.

“When we looked for commonalities among former players who believed they had CTE, we saw that they were significantly more likely to self-report not only cognitive symptoms — issues with memory, thinking, concentration — but also a number of conditions that cause cognitive problems such as headaches, low testosterone, depression, and pain,” Grashow told MedPage Today.

“In a sense, this is a heartening finding, because long-established, safe, and efficacious treatments for many of these conditions are available,” she added.

The study also didn’t assess traumatic encephalopathy syndrome (TES), a possible clinical syndrome of CTE. Suicidality is not part of the 2021 TES diagnostic criteria due to a lack of evidence directly linking it with CTE, noted Michael Alosco, PhD, of Boston University, and Kristine Yaffe, MD, of the University of California San Francisco.

Several high-profile football players have died by suicide, and there may be a public perception that a link between CTE neuropathology and suicidality exists, Alosco and Yaffe observed in an accompanying editorial.

“We underscore the following: (1) there are no data that directly link CTE neuropathology and suicidality or suicide, and (2) findings from the current study should not be construed to mean that one’s perception of having CTE will independently lead to suicidality,” the editorialists emphasized.

“The elevated rate of suicidality in the perceived CTE group is best attributable to this group having several risk factors for suicidality, including younger age, more psychiatric symptoms, greater concussion burden from football, and increased likelihood of having reported dementia diagnoses,” they added.

From 2017 to 2020, Grashow and colleagues surveyed participants in the Harvard Football Players Health Study. The sample included American-style football players who contracted with any professional league from 1960 to 2020. Most were NFL players, but some were part of the American Football League (AFL) before it merged with the NFL in 1970, Grashow said.

Overall, 15,011 players were invited to participate. Of these, 4,180 enrolled in the study, and 1,980 (47.4%) answered questions about perceived CTE and self-harm.

Participants were asked a yes/no question about whether they believed they had CTE. “Deliberately, no definition of CTE was provided,” Grashow and colleagues noted.

Depression symptoms over the past 2 weeks were assessed with the nine-item Patient Health Questionnaire, which asked about “thoughts that you would be better off dead or hurting yourself,” the researchers said. “If the respondent endorsed several days, more than half the days, or nearly every day for this item, he was classified as experiencing suicidality.”

Respondents were age 58 years on average when they completed surveys and had a mean professional football career duration of 7 years. One in three former players (30.1%) was Black.

Men who perceived CTE were an average of 5.4 years younger than those without perceived CTE. Nearly 20% of former players with perceived CTE reported being diagnosed with Alzheimer’s disease, vascular dementia, or another dementia, compared with about 3% of those without perceived CTE.

Subjective cognitive difficulties were the strongest predictor of perceived CTE, followed by low testosterone levels, concussion scores, depressive symptoms, emotional and behavioral dyscontrol symptoms, and pain intensity.

The researchers acknowledged that the study may not be representative of all former pro players. “This study cannot get at the directionality of whether believing one has CTE leads to suicide, or whether suicidality is caused by the processes that underlie the neuropathological changes,” Grashow noted.

“But, in a way, that’s not really what this paper is about, since we cannot know who will ultimately be diagnosed with CTE,” she said. “What we do know is that those with beliefs about CTE have a number of treatable conditions.”