Chronic traumatic encephalopathy (CTE) is often linked to professional football, but experts emphasize that the condition affects a broader range of individuals. Athletes in sports such as soccer, hockey, boxing, and mixed martial arts are also at risk due to repeated impacts to the head. Other causes include combat situations, domestic violence, and car accidents.
In response to these risks, both youth and professional sports organizations have introduced new helmets, updated rules, and improved safety protocols to protect players from head injuries. Despite these efforts, repeated trauma can still increase the likelihood of developing CTE.
CTE is not officially recognized as a diagnosis and is neither genetic nor contagious. It is considered a form of dementia with symptoms that may appear years after brain injury. These symptoms include memory loss, confusion, impaired judgment, behavioral changes such as aggression or erratic actions, mood swings including depression or paranoia, movement difficulties, and an increased risk of suicidal thoughts or attempts. As the disease progresses over time, it can lead to severe complications like loss of basic functions and a weakened immune system.
Doug Johnson-Greene, Ph.D., M.P.H., ABPP, a neuropsychologist with the University of Miami Health System, explained: “In persons who are presumed to have CTE, there are often a number of characteristics of other neurological diseases, such as Parkinson’s disease. It’s not clear if CTE is a distinct clinical entity.
“A highly similar, and perhaps identical disorder, pugilistic Parkinsonism, was described as early as the 1940s among professional boxers,” he said. “In these cases, what is known is that there’s a higher deposition of the brain protein p-tau, which is seen in many neurodegenerative disorders, including Alzheimer’s disease.”
Experts believe that repeated head trauma leads to damage in the brain by causing abnormal accumulation of tau protein (p-tau). Normally stabilizing neurons’ internal structures, p-tau becomes harmful when it builds up excessively. This buildup disrupts neuronal function and triggers chronic inflammation in the brain—a process called immunoexcitotoxicity—which results in further cell damage and death.
As CTE advances within the brain from initial sites in the cortex to other regions, widespread atrophy occurs. In some cases additional proteins accumulate as well. Diagnosis can only be confirmed postmortem through examination of brain tissue.
“Concussions are a complex topic,” Dr. Johnson-Greene said. “Being knocked unconscious is not necessary for a concussion (using our current definitions). All concussions fall under the category of ‘mild head injury.’ The definition of a concussion is any blow to the head that causes at least one neurological symptom.
“Unfortunately,” he continued,“the blow to the head and associated neurological symptoms are all based on self-report—and people are not accurate reporters of events like this nor their own symptoms.”
He added: “More severe blows to the head can be potentially more problematic especially if adequate time for recovery between concussions did not occur. Most significant concussions are associated with a period of unconsciousness for at least a few minutes and up to 30 minutes. But repeated concussions—especially those that do not allow adequate time for recovery before another occurs—are one of the hypothesized mechanisms for CTE.”
Research on CTE has focused largely on football players because they frequently experience concussions and often participate in related studies aimed at improving athlete safety. However,“contact sports are generally safe,” Dr. Johnson-Greene noted.“The general consensus in the medical community is that benefits of regular exercise through contact sports (below collegiate level or other modalities) outweigh risks. It is far more likely to have problems with cardiovascular disease during one’s lifetime; actual risk for developing CTE appears very small.”
If someone sustains a head injury or suspects they have had a concussion they should seek medical attention promptly.A neurologist can assess cognitive functions and may recommend rest for recovery.Currently there is no cure for CTE but various therapies—including cognitive behavioral therapy,memory training,and medications—can help manage certain symptoms.Physical therapy addresses movement issues while occupational therapy teaches new strategies for daily tasks.Lifestyle adjustments,such as regular exercise,sufficient sleep,and maintaining an anti-inflammatory diet,might also support overall health.
