Junior Seau had CTE, study reveals

A study of Junior Seau's brain by the National Institutes of Health revealed that the former NFL linebacker suffered from a degenerative brain disease known as chronic traumatic encephalopathy when he committed suicide last May. ABC News and ESPN reported the findings of the NIH study Thursday morning on Good Morning America.

Seau's family requested an analysis of his brain following his death on May 2, 2012. He was 43 at the time.

Depression, mood swings, emotional detachment; Seau's family described side effects of the condition that marked the NFL great's final years. Tyler Seau described his father's condition on the program:

"I was not surprised after learning a little about CTE that he had it. He did play so many years at that level. I was more just kind of angry I didn't do something more and have the awareness to help him more, and now it is too late.

"I don't think any of us were aware of the side effects that could be going on with head trauma until he passed away. We didn't know his behavior was from head trauma.

"He emotionally detached himself and would kind of 'go away' for a little bit," Tyler Seau said. "And then the depression and things like that. It started to progressively get worse."

The 20-year NFL veteran's death was one of several high-profile suicides among former players suffering from CTE. A month before Seau's death, former Atlanta Falcons safety Ray Easterling took his own life after years of battling similar conditions. A study of his brain revealed that he suffered from CTE as well. Former Bears safety Dave Duerson killed himself in 2011, leaving a note requesting that his brain be used for research into the impacts of head trauma. Researchers later confirmed that he too had CTE.

The NFL released a statement on Thursday morning, following the report, pointing to league-funded research into head trauma. The league's statement read:

We appreciate the Seau family's cooperation with the National Institutes of Health. The finding underscores the recognized need for additional research to accelerate a fuller understanding of CTE. The NFL, both directly and in partnership with the NIH, Centers for Disease Control and other leading organizations, is committed to supporting a wide range of independent medical and scientific research that will both address CTE and promote the long-term health and safety of athletes at all levels. The NFL clubs have already committed a $30 million research grant to the NIH, and we look forward to making decisions soon with the NFL Players Association on the investment of $100 million for medical research that is committed in the Collective Bargaining Agreement. We have work to do, and we're doing it."

Thousands of former NFL players are suing the league for negligence over the issue of the impact of head trauma, claiming that the NFL deliberately concealed information about concussions and player safety. A federal district court in Pennsylvania is currently hearing arguments about whether to dismiss the case before it goes to trial.

A study conducted by the Centers for Disease Control released in September 2012 showed that former NFL players are at higher risk of death from neurological diseases.