A post-mortem examination showed unusually severe brain disease in the frontal lobe of a former NFL player accused of fatally shooting six people before killing himself, a coroner said.
The 20 years Phillip Adams spent playing American football “definitely… gave rise” to a diagnosis of stage 2 chronic traumatic encephalopathy, said Dr Ann McKee, who examined Adams’ brain.
Authorities have said Adams killed physician Robert Lesslie, his wife Barbara, two of their grandchildren – nine-year-old Adah Lesslie and five-year-old Noah Lesslie – and two engineers working at the Lesslie home, James Lewis and Robert Shook, both 38.
The incident happened in April in Rock Hill, South Carolina. Police later found Adams with a self-inflicted gunshot wound to the head.
The degenerative disease known as CTE is linked to head trauma and concussions and has been shown to cause a range of symptoms, including violent mood swings and memory loss.
Dr McKee, who directs the CTE Centre at Boston University, 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.
The second stage is associated with progressive cognitive and behavioural abnormalities such as aggression, impulsivity, explosivity, depression, paranoia, anxiety, poor executive function and memory loss, Dr McKee said.
But Adams’ diagnosis was different from the other young players because it was “unusually severe” in both his frontal lobes, she said.
Dr McKee compared Adams’ brain to that of Aaron Hernandez, another former NFL star who was posthumously diagnosed with CTE after he hanged himself in prison at the age of 27 while serving a life sentence for a 2013 murder.
The Lesslie family said they appreciated the diagnosis.
“Even in the midst of crushing heartbreak, we are finding some comfort in the CTE results and the explanation they provide for the irrational behaviours pertaining to this tragedy,” their family statement said.
Adams’ family said in a prepared statement that they were not surprised by the results, but were shocked to learn how severe his condition was.
“After going through medical records from his football career, we do know that he was desperately seeking help from the NFL but was denied all claims due to his inability to remember things and to handle seemingly simple tasks, such as travelling hours away to see doctors and going through extensive evaluations,” the statement said.
CTE, which can only be diagnosed through a post-mortem, has been found in former members of the military, American football players, boxers and others who have been subjected to repeated head trauma.
One recent study found signs of the debilitating disease in 110 out of 111 NFL players whose brains were inspected.
Adams, 32, played 78 NFL games for six teams over six seasons.
He joined the San Francisco 49ers in 2010, and though he rarely started, he went on to play for New England, Seattle, Oakland and New York Jets before finishing his career with 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 would not have been eligible for testing as part of a broad settlement between the league and former players over long-lasting concussion-related injuries.
His sister told USA Today after the killings that her brother’s “mental health degraded fast and terribly bad” in recent years and the family had noticed “extremely concerning” signs of mental illness, including an escalating temper and personal hygiene neglect.