HARRISBURG, Pa. -- Researchers have confirmed that a former NFL lineman from Pennsylvania who died of suicide at 25 had the brain disease known as chronic traumatic encephalopathy.
Adrian Robinson Jr.'s diagnosis was confirmed Wednesday through officials at the NFL brain bank at Boston University.
Family lawyer Ben Andreozzi says Robinson had several concussions during two seasons in the league. The family has not filed suit over his May death in Philadelphia.
"He went from being one of the nicest guys you'd ever want to talk to, to having a darker edge at times," Andreozzi said. "The family started noticing changes in his behavior and didn't know why."
Robinson, of Harrisburg, appeared in 12 games for the Pittsburgh Steelers in 2012. In 2013, he played six games for the Denver Broncos and two for the San Diego Chargers.
Robinson had signed with the Canadian Football League's Hamilton Tiger-Cats as a free agent April 27.
He played for Temple University before turning pro.
Scientists continue to debate the potential links between concussions, CTE and suicide.
Concerns about repeated concussions have led to congressional hearings and new rules on when student and professional athletes can return to play.
Chris Nowinski of the Boston University-affiliated Concussion Legacy Foundation confirmed Robinson's CTE diagnosis.
He said that 88 of 92 NFL players whose brains have been tested there have shown evidence of CTE, along with 33 others who played college or high school football. The brains are studied posthumously when families seek testing.
Information from The Associated Press was used in this report.