Former NFL player Phillip Adams, who shot to death six people and killed himself, suffered from CTE

Phillip Adams, the former NFL player who in April shot to death six people before killing himself, suffered from the debilitating brain disease chronic traumatic encephalopathy (CTE), the doctor who conducted the brain study announced Tuesday.

Ann McKee, a neuropathologist who as director of Boston University CTE Center led the examination of Adams’ brain, presented the findings during a press conference that included Sabrina Gast, the corner of York County, South Carolina, where the killings occurred April 7.

CTE, the neurodegenerative disease linked to concussions and repetitive head trauma from football and other contact sports, has been associated with behavioral and mood changes, according to the Mayo Clinic and multiple studies.

Adams, a cornerback who played college football at South Carolina State, was a seventh-round pick of the San Francisco 49ers in the 2010 NFL draft. Between 2010 and 2015, he played for six teams – the 49ers, New England Patriots, Seattle Seahawks, Oakland Raiders, New York Jets and Atlanta Falcons – was 32 at the time of the killings.

He died from a self-inflicted gunshot wound and his family members donated his brain to the Boston University CTE Center. CTE can be diagnosed only after death with brain tissue analysis.

Adams’ sister, Lauren, told USA TODAY Sports that Phillips Adams’ behavior “shifted dramatically’’ over the past couple of years.

“His mental health degraded fast and terribly bad,” Lauren Adams told USA TODAY Sports the day after the shootings. “There was unusual behavior. I’m not going to get into all that (symptoms). We definitely did notice signs of mental illness that was extremely concerning, that was not like we had ever seen. …

“He wasn’t a monster. He was struggling with his mental health.”

Adams’ case has fueled ongoing talk about the apparent…