Aaron Hernandez, former New England Patriots and convicted murderer, was 27 when he committed suicide this past April. An examination of his brain showed he had such a severe form of the degenerative brain disease Chronic Traumatic Encephalopathy (CTE) and the damage was similar to that of players in their 60s, according to the NY Times.

CTE is a progressive and deteriorating brain disease found in “athletes, military veterans, and others with a history of repetitive brain trauma,” stated the Concussion Foundation. With Hernandez’s death, it opens new light into the damages of concussion and brain damage with football. CTE can only be found in autopsies, making diagnosis difficult.

Evidence states that CTE is caused by repetitive hits to the head over a period of years. This does not mean a number of concussions. Most people diagnosed with CTE suffered hundreds or thousands of head impacts over the course of many years playing contact sports. In this case, football with repetitive hits to the head by the helmet. The biggest factor found is sub-concussive impacts meaning that they are not strong enough to cause full concussions but enough to do sometimes unseen damage at first.

Dr. Ann McKee, the director of the CTE Center at Boston University, said Hernandez had stage 3 (out of 4) of the disease. At that point, it can cause violent mood swings, depression and other cognitive disorders, according to ESPN.

His lawyer announced a lawsuit against the NFL and the team, accusing them of hiding the true dangers of the sport, according to ESPN. “We’re told it was the most severe case they had ever seen for someone of Aaron’s age,” Attorney Jose Baez said.

In July, a study conducted by the Journal of the American Medical Association (JAMA) more than 99 percent of brains studied of deceased NFL players were examined and contained CTE. The study had 202 football players brains studied. Researches found CTE in 110 of the 111 brains of former NFL players. CTE was found in 48 of 53 college players and three of 14 high school players. This was the largest study of its kind, according to Bleacher Report.

“Although the disease cannot be formally diagnosed until after death, many of the symptoms of CTE that may be experienced during a lifetime, such as depression or anxiety, are treatable,” Dr. Jeffrey Kutcher, national director of the Sports Neurology Clinic at the Core Institute said according to CNN. “That is why it’s important for someone experiencing these symptoms to access a comprehensive evaluation by a neurologist, and work with them to figure out a treatment plan.”

Hernandez’s brain findings could allow more careful analysis on football players and their attitudes. With Hernandez’s brain at stage 3, he was prone to many cognitive disorders which raises questions as to what other football players are enduring now in their living lives.