Memory and cognitive problems were common among some former NFL players later diagnosed with CTE, study finds

Problems with memory and cognitive functioning were common among some former NFL players who had neurocognitive testing done after their retirement and later died with chronic traumatic encephalopathy (CTE), a brain disease linked to repetitive head trauma, a study published Wednesday found.

Researchers at the Boston University CTE Center studied the brains of 33 former NFL players that were donated to them between 2017 and 2025 who were diagnosed with CTE and previously underwent neurocognitive testing. The average age of death was 65.

The neurocognitive testing was conducted through the court sanctioned NFL Concussion Settlement’s Baseline Assessment Program (BAP), which determines eligibility of former NFL players to receive concussion-related injury compensation, with scores ranging from a low of 0 to a high score of 2.

In the study, memory problems, especially short-term memory, were the most common finding, affecting 63% of these players. Others included impairments in executive function (52%), language (41%) and attention (26%).

Seven former players in this study were diagnosed with the highest stages of CTE on autopsy. Six had deficits in learning and memory in life per independent testing but all scored a level zero at the time of their BAP testing, which is not an eligible score for compensation as outlined by the NFL concussion settlement.

"Our study wasn't designed to meaningfully evaluate the settlement program as a whole. However, we did identify limitations of the testing program. Our data suggest that it’s likely that the BAP is suboptimal in identifying players who are in need of support," Anna Aaronson, lead researcher of the study and a neuroscience Ph.D. candidate at Boston University, told ABC News. "BAP criteria may be too strict, and we need to better align the BAP testing with clinical care standards to ensure individuals are receiving the support they need," she added.

The NFL said in a statement: "A federal judge administers the settlement agreement, which was negotiated at arms-length by sophisticated counsel for all parties and thoroughly scrutinized, vetted and approved as fair by the district and appeals courts. All decisions - legal, medical, diagnostic and monetary awards - are made independently of the NFL and overseen by the court."

Currently, CTE can only be diagnosed after death by looking at the brain through a microscope. NFL players have been found to be particularly at risk for this condition given the repeated head injuries they sustain over a typical career.

A separate study published last week estimates at least one in four former NFL players who died between 2016 and 2021 had CTE.

It was also found that NFL players who died with high-stage CTE had worse impairments in language and memory in life based on testing from independent mental health professionals.

"The key impairments in specific cognitive domains were within the memory domain, and we established a link between objective neuropsychological testing and CTE," Aaronson said.

"We tied CTE neuropathology to neurocognitive testing for the first time," Aaronson added.

She noted that the research findings may help advance efforts to diagnose CTE before death and help prevent missed cases of CTE in life.

Dr. Varun Mehta is a fourth-year resident at Mount Sinai Hospital and a member of the ABC News Medical Unit.