The family of Junior Seau has filed a wrongful death lawsuit against the NFL, claiming the linebacker’s suicide last May was caused by head trauma he sustained over more than 20 seasons in the league.

The lawsuit, filed Wednesday, alleges the NFL deliberately hid from players the dangers of repetitive blows to the head.

The suit comes less than two weeks after researchers at the National Institutes of Health announced Seau’s brain had tested positive for Chronic Traumatic Encephalopathy (CTE). The condition, which has been documented in the brains of 50 deceased football players — including 33 who played in the NFL — is associated with repeated head trauma. It can lead to dementia, memory loss, and depression.

“We were saddened to learn that Junior, a loving father and teammate, suffered from CTE,” the Seau family said in a statement to the Associated Press. “While Junior always expected to have aches and pains from his playing days, none of us ever fathomed that he would suffer a debilitating brain disease that would cause him to leave us too soon.”

Seau retired from football in 2009. His son, Tyler, told the AP that in the final years of his life, Seau experienced mood swings, forgetfulness, insomnia and depression.

“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 Seaus allege in their lawsuit that the NFL placed profit above the health of players.

“The NFL knew or suspected that any rule changes that sought to recognize that link (to brain disease) and the health risk to NFL players would impose an economic cost that would significantly and adversely change the profit margins enjoyed by the NFL and its teams,” the Seaus said in the suit.

Brian McCarthy, an NFL spokesman, told FRONTLINE that league attorneys will review the lawsuit “and respond to the claims appropriately through the court.”

Many of the allegations in the Seau family’s suit mirror those in a separate case against the NFL brought by more than 4,000 former players. Central to that case is what the league knew about the link between brain damage and professional football and when. A November investigation by FRONTLINE and ESPN found that the NFL’s retirement board awarded disability payments to at least three former players after determining football caused their brain injuries. According to the investigation, the board made the payments even as the league’s top medical experts denied any link between the sport and long-term brain damage.

Since 2009, under pressure from Congress, the NFL has adopted several rule changes designed to limit head injuries. The league has cracked down on helmet-to-helmet hits, moved up kickoffs, and issued new guidelines on when a player can return to the field after showing concussion symptoms. Teams have also committed a $30 million research grant to the NIH.

The Seaus are additionally suing the helmet manufacturer Riddell, claiming the company was negligent in the design, testing, assembly and manufacturing of helmets used by NFL players.

A spokeswoman for Riddell said in a statement, “We have not yet received the complaint; however, it’s not appropriate to comment on pending litigation. We are confident in the integrity of our products and our ability to successfully defend our products against challenges.”