"They said you have PTSD you gotta start writing because this is how you get to the solution. The only way out is through so I started writing all these dark chapters of my life," the actor said on Wednesday about the experience.
"It wound up being this script-form thing, sent it to my friend, became a movie," he continued.
Honey Boy, which opens in theaters on Friday, also stars LaBeouf as a fictionalized version of his father. The film features Noah Jupe and Lucas Hedges portraying a young and older version of a character based on LaBeouf.
The movie, directed by Alma Har'el, chronicles LaBeouf's struggles as a child actor and his tense relationship with this father.
"My dad's a pretty off-color character, he wasn't like too enthused about me playing him," LaBeouf said.
"So I lied to him and told him that Mel Gibson would be playing him," he continued about how he got his father to sign off on Honey Boy.