Pat says he is estranged from his father, John, because he claims John is delusional, violent, paranoid and dangerous, and that his father’s behavior scares him so much, he fears for his family’s safety. Pat also says his father responds to seemingly benign events with what John interprets as threats, explaining that after his 7-year-old son sent his grandfather a thank you note, John responded with a three page letter accusing Pat and his wife of sending a “murder” letter.

WATCH: Son Calls Father ‘Paranoid,’ Delusional, Dad Says Son Is Violent And Threatening

However, John says he’s the one who should be afraid. He claims that Pat has been violent toward him, once putting him in a headlock and dislocating his neck. He also claims that Pat has a genetically transferred chemical imbalance which gave him a mental illness and has caused his violent past.

In the video above, John tells Dr. Phil that he believes he contracted Agent Orange in Vietnam and that it was passed down to Pat, causing his "mental illness." 

“You contracted Agent Orange, that’s your theory, and you say that it’s been passed on to him, which is why he is mentally ill,” Dr. Phil says to John, and asks him what he believes is Pat’s "mental illness." 

“It’s an emotional disorder,” John says. “He reverses things, turns things around.”

On Tuesday’s episode, Dr. Phil attempts to help this family reunite and patch their volatile relationship. Watch more here.