Calling the film industry a "disgusting place", Timothy said he believes the showbiz also contributed to his elder son's alcoholism.
"It has taken a toll on both of my sons. Hollywood is a disgusting place. I think that's been a major factor in Ben's drinking.
"You're kind of forced to develop a persona that is hard to shed and go home to your family. It affects your whole life. I think that's one of the dangers of the film industry," Timothy told Grazia magazine.
"I had to recover and, happily, I did. Ben has always been serious about getting sober. There is no question about that. He wants a balanced life and he is working at it," he added.
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Timothy also reflected that fame cost Ben, 45, his marriage with actor Jennifer Garner. The couple split in 2015.
"It's difficult to balance family life in the midst of global stardom. It's a hard, taxing life."
He dismissed the allegations of sexual misconduct against his sons.
Hilarie Burton claimed Ben groped her when she was a host of MTV's TRL in 2003, for which the actor offerd an apology apologised saying he does not remember the incident.
Casey, 42, went for an out-of-court settlement in case of sexual harassment in 2010, when two female crew members accused him of inappropriate behaviour after they worked with him on the sets of "I'm Still Here".