Jesse Fann, professor of psychiatry and behavioral sciences at the University of Washington School of Medicine, is the lead author of a paper in Lancet Psychiatry, "Long-term risk of dementia among people with traumatic brain injury in Denmark: a population-based observational cohort study." It's one of the largest studies done on the link between traumatic brain injury and dementia.

"The data show that with even a history of a single traumatic brain injury, seems to increase the risk. And the risk is associated with the number and severity of traumatic brain injuries." Fann said. "As the number of traumatic brain injuries increases, the risk also increases in a very clear pattern."

Fann discusses the topic in this downloadable video segment.