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.

“Many conditions common to former NFL players such as sleep apnea, low testosterone, high blood pressure and chronic pain can cause problems with thinking, memory and concentration,” said lead investigator Rachel Grashow, a research scientist with the Harvard T. H. Chan School of Public Health.