The former NFL player suspected of fatally shooting six people in South Carolina before killing himself in April suffered from an "unusually severe" form of the degenerative brain disease chronic traumatic encephalopathy, or CTE, the Boston University doctor who conducted the brain autopsy announced Tuesday.
Dr. Ann McKee, a neuropathologist who serves as director of Boston University's CTE Center, said ex-football pro Phillip Adams had stage 2 CTE in both frontal lobes of his brain. McKee said that of 24 NFL players diagnosed with the disease after dying in their 20s and 30s, most had stage 2, like Adams. The disease has four stages, with stage 4 being the most severe and usually associated with dementia.
"Mr. Adams' CTE pathology was different than the other young NFL players with CTE," McKee said. "It was different in that it was unusually severe in both frontal lobes."
She compared his brain scans to that of former Patriots' tight end Aaron Hernandez, who was also posthumously diagnosed with CTE after he died by suicide in 2017 while serving a life sentence for a 2013 murder.
Get top local stories in San Diego delivered to you every morning. >Sign up for NBC San Diego's News Headlines newsletter.
CTE, the degenerative disease linked to head trauma and concussions, has been shown to cause a range of symptoms, including violent mood swings and memory loss. McKee said Stage 2 CTE is associated with aggression, impulsivity, depression, paranoia, anxiety and poor executive function. She said Adams' 20-year football career "definitely" contributed to his diagnosis.
"We have seen this behavior," McKee said. "We have even seen homicidal behavior in individuals diagnosed with CTE. It is difficult to say that it alone resulted in these behaviors because usually, it's a complicated issue with many other factors. It is in fact, not what I would consider unusual in this disease."
Authorities have said that on April 7, Adams killed Rock Hill physician Robert Lesslie; his wife, Barbara; two of their grandchildren, 9-year-old Adah Lesslie and 5-year-old Noah Lesslie; and two HVAC technicians working at the Lesslie home, James Lewis and Robert Shook, both 38. Police later found Adams with a self-inflicted gunshot wound to the head.
SportsWrap
The top sports headlines of the day
Adams' family agreed shortly after his death to have his brain tested for CTE.
CTE, which can only be diagnosed through an autopsy, has been found in former members of the military, football players, boxers and others who have been subjected to repeated head trauma. One recent study found signs of the debilitating disease in 110 of 111 NFL players whose brains were inspected.
Adams, 32, played in 78 NFL games for six teams over six seasons. He joined the San Francisco 49ers in 2010 as a seventh-round draft pick out of South Carolina State, and though he rarely started, he went on to play for New England, Seattle, Oakland and the New York Jets before finishing his career with the Atlanta Falcons in 2015.
As a rookie, Adams suffered a severe ankle injury and never played for the 49ers again. Later, with the Raiders, he had two concussions over three games in 2012. Because he didn't retire by 2014, he wouldn't have been eligible for testing as part of a broad settlement between the league and former players over long-lasting concussion-related injuries.
A spokesperson for Adams' family said he was "desperately seeking help" from the NFL but was denied "all of his claims" because he had trouble remembering things and struggled to complete simple tasks, such as traveling to visit doctors and undergoing extensive evaluations.
"We now know that these deficits were most likely caused by the disease," the family said.
McKee said players who are suffering with CTE fall through the cracks and are least likely to get help because of the "huge obstacles" created by the NFL.
"This is a man who is not thinking clearly, is having problems with planning and organization," McKee said. "Yet, they have to fill out very extensive paper, which is usually beyond people who are impaired."
She called on the NFL to create a "comprehensive care package and evaluation system" to give former players the care and management they deserve.
The football league and Adams’ agent did not immediately respond to requests for comment.
Adams’ sister told USA Today after the killings that her brother’s “mental health degraded fast and terribly bad” in recent years and that the family noticed “extremely concerning” signs of mental illness, including an escalating temper and personal hygiene neglect.
"We are pleased to have a better understanding of the mental turmoil that Phillip was dealing with during the last moments of his life," his family said. "We cannot say that we are surprised by these results, however it is shocking to hear how severe his condition was."
If you or someone you know is at risk of suicide please call the U.S. National Suicide Prevention Lifeline at 800-273-8255, text TALK to 741741 or go to SpeakingOfSuicide.com/resources for additional resources.
