Depp, who shares two children, Lily-Rose, 26, and Jack, 23, with former partner Vanessa Paradis, said his mother's behavior taught him what he wanted to avoid as a father.
"She taught me how not to raise kids. Just do the exact opposite of what she did," he said.
The actor first opened up about these traumatic experiences during his 2022 $100 million defamation trial against ex-wife Amber Heard.
In court, Depp denied all allegations of abuse, and the case became a media firestorm that left both actors sidelined by major studios.
"In our house, we were never exposed to any type of safety or security, the only thing to do was stay out of the line of fire," he said while on the stand.
"My mother was quite unpredictable. She had the ability to be as cruel as anyone can be with all of us," Depp added.
After moving from Kentucky to Florida, Depp's family lived in a motel for nearly a year. The physical and emotional toll of his mother's behavior left lasting marks.
"Physical violence, physical abuse. That was a constant," Depp recalled. "We were all somewhat shell-shocked. She'd walked past, you'd shield yourself because you didn't know what would happen."
He added: "She could become quite violent, and she was quite violent, and she was quite cruel. There was physical abuse, certainly, which could be in the form of an ash tray being flung at you, or you'd get beat with a high heeled shoe, or a telephone, or whatever's handy."
While the physical violence Depp endured at the hands of his mother was harrowing, he revealed that it was the emotional turmoil that left the deepest scars.
"The verbal abuse, the psychological abuse, was almost worse than the beatings," he explained. "The beatings were just physical pain. The physical pain, you learn to deal with. You learn to accept it. You learn to deal with it."
In the same interview, Depp addressed the abrupt end of his role as Gellert Grindelwald in the "Fantastic Beasts" series.
Despite already filming scenes for "The Crimes of Grindelwald" in 2018, he said the decision to remove him was swift and unexpected.
"It literally stopped in a millisecond," he told the publication. "Like, while I was doing the movie. They said we'd like you to resign. But what was really in my head was they wanted me to retire."
Refusing to be erased, Depp said his response was defiant: "F-ck you. There's far too many of me to kill. If you think you can hurt me more than I've already been hurt, you're gravely mistaken."
Personal betrayals compounded Depp's professional challenges amid his legal battle with Heard.
Just last month, the actor opened up about feeling "deserted" by three of his closest friends after abuse allegations emerged from his turbulent divorce.
Reflecting on that time, Depp, speaking to the Sunday Times, said: "I'll tell you what hurts. There are people, and I'm thinking of three, who did me dirty. Those people were at my kids' parties, throwing them in the air."
He continued: "Look, I understand people who could not stand up [for me] because the most frightening thing to them was making the right choice."