In a sensational new book Patrick Kennedy, former Congressman and son of Senator Edward Kennedy, says his father was an alcoholic who suffered from post traumatic stress disorder as a result of the assassination of his two brothers.

He says the family attempted an intervention with his father but Teddy Kennedy resented it deeply.

“I can now see my father suffered from PTSD, and because he denied himself treatment — and had chronic pain from the back injury he received in a small plane crash in 1964 when he was a very young senator — he sometimes self-medicated in other ways,” Kennedy writes in the book, “A Common Struggle: A Personal Journey Through the Past and Future of Mental Illness and Addiction.”

Kennedy says he believes his father suffered from post-traumatic stress disorder after living through the assassinations of both of his brothers, President John F. Kennedy and Senator Robert Kennedy.

Kennedy writes, that he and his family met Teddy Kennedy at his house in McLean, Va., for an “intervention.” 

“‘Dad, we’re concerned, we’re worried about you, and we think you’re drinking too much,’” Kennedy recalls him and his siblings saying according to the Boston Globe . “Then we all cried.”

“He took it the exact opposite way we had hoped,” he writes. The senator thought his children were taking sides against him, siding with “those people” who didn’t understand how difficult his life was.“I’ve been seeing a priest,” Ted Kennedy said. “But you wouldn’t know that. If you had bothered to ask me rather than just accusing me, you would have known I’m trying to get help.”

With that, Kennedy writes, his father got up and walked out of the room. “That was it.”

Patrick, who suffers from bipolar disorder, says his relationship with his father became so bad that Teddy suggested he no longer stay with him when in Washington but stay with his sister Kara or stay with his mother Joan on Cape Cod when in Boston.

The book, which Kennedy will discuss on CBS’s “60 Minutes” Sunday night, has deeply upset other members of the family.

All have refused to acknowledge it or speak to the press.

“I know how some of them are going to react,” Kennedy says in a brief show excerpt released by CBS. “They’re angry.”

The Boston Globe reported his mother, Joan, and his brother, Ted Kennedy Jr., did not respond to messages on Saturday, nor did Senator Kennedy’s widow, Vicki.

Patrick Kennedy is a former eight-term Democratic congressman from Rhode Island who retired in 2010 and has since married and had two children. He has become a full-time advocate to prevent drug and alcohol use ruining people’s lives.

He says he was badly addicted to drugs and drink. One of his worst offenses he recalls was vomiting on Air Force One when on a trip to Ireland with President Clinton after too many rum and cokes.

Kennedy says that after his father died in 2009, he was given a letter that his father had written in 1980 in case he was assassinated during a run for president.

“In it, he talked about how much he loved me, and how I had given him so much love,” Kennedy writes. “He said he would never forget the times we went fishing and sailing.”

He said he told his father he would not attend his 60th birthday party in 1992 if he kept drinking.

His father was deeply upset Patrick went public with his addiction in a New York Times article in 2006 after he had been arrested for crashing into a barrier at the US Capitol, 

“He called the article a disaster — the word he always used to describe the most extreme situations,” Kennedy writes.

“How dare I talk about the family this way? How dare I discuss ‘these things’ in public? I stood there on the verge of disintegration. I was early in my sobriety and still pretty vulnerable. And I watched my father circulate around the room, talking about the article.’’

Only his cousin Maria Shriver, former wife of Arnold Schwarzenegger, challenged Ted Kennedy.

“I think what Patrick did was fantastic,” Maria said, according to the book. 

“That’s what we need in this family, someone to talk about this.”

Patrick Kennedy will appear on “60 Minutes“ Sunday night.

The late Sen. Ted Kennedy with his son, Rep. Patrick Kennedy.LEAHY/AP