Researchers have concluded that chronic traumatic encephalopathy (CTE) should be considered an independent cause of dementia, distinct from other well-known forms such as Alzheimer’s disease.

This largest study of its kind shows that individuals with the most severe manifestations of CTE are four times more likely to develop dementia than those without the condition.

Chronic traumatic encephalopathy is a degenerative brain disease that develops as a result of repeated head impacts and traumatic brain injuries. It is most commonly recognized in people involved in contact sports, such as American football or boxing, where multiple minor head injuries accumulate over the years.

The study, published in Alzheimer’s & Dementia, analyzed 614 donor brains from individuals with known exposure to repeated head trauma but without other neurodegenerative diseases. Researchers identified 366 cases associated solely with CTE and compared them with 248 cases without the pathology. They found that individuals with the most severe CTE had a dementia risk comparable in magnitude to that seen in advanced Alzheimer’s disease, the leading cause of dementia worldwide.

In CTE, pathological tau protein tangles accumulate in the brain, leading to neuron death and cognitive decline. Currently, CTE can only be diagnosed postmortem through brain tissue analysis, making early detection and treatment challenging.

The authors emphasize that recognizing CTE as a distinct cause of dementia is crucial for accurate diagnosis, patient care, and the development of future treatments, especially for individuals with a history of repeated head injuries.