Johnny Depp says his consumption of drugs and alcohol over the years has never been “for a party” but rather to numb himself from “the ghosts from my youth”.
The actor said his “substance abuse” had been “grossly embellished” by Amber Heard and that many of her allegations were “plainly false.”
Mr Depp, 58, is suing the Aquaman star for libel over a 2018 article she wrote in The Washington Post, which his lawyers say falsely implies he physically and sexually abused her.
Much of the evidence heard so far at the US trial, taking place in Virginia, has made reference to his use of substances while the two were together, which Ms Heard’s lawyers said have triggered violent episodes.
Giving evidence on Tuesday, Mr Depp said his drug-taking had started at the age of 11, when he took his mother’s nerve pills “to escape feeling so much”.
“(It’s) a pretty young age to do that, I can’t say that I’m proud of admitting to that but I have to say that I knew not what else to do,” he said.
“I’ve never used (the word) party in my life, I’ve never taken any substance for a party.
“I have taken these substances over the years, on and off, to numb myself of the ghosts, the wraiths that were still with me from my youth.”
“It was essentially self medication, one of those get-me-out-of-here moments, where what you want to escape from is your own brain, your own head.”
He added: “The characterisation of my ‘substance abuse’ that’s been delivered by Ms Heard is grossly embellished and, I’m sorry to say, but a lot of it is just plainly false.
“I am not some maniac that needs to be high or loaded all the time.”
Mr Depp also admitted that he was “ashamed and embarrassed” by text messages he had sent previously, which contained abuse directed at Ms Heard, saying that in the “heat of the moment” he had gone to “dark places”.
The actor said had initially thought his relationship with Ms Heard had been “too good to be true” but had noticed things that “might be a bit of a dilemma at some point”.
“She was attentive, she was loving, she was smart, she was kind, she was funny, she was understanding and we had many things in common,” he told the court.
“For that year or year and a half it was amazing, there were a couple of things that stuck in my head that I noticed that I thought might be a little bit of a dilemma at some point.”
At the start of his evidence the actor said he was “obsessed with truth” and that he “did not deserve” to have the “heinous and disturbing” allegations levelled at him.
“It was a complete shock… it just didn’t need to go in that direction as nothing of the kind had ever happened,” he said.
“(In) the relationship there were arguments and things of that nature, but never did I myself reach the point of striking Ms Heard in any way, nor have I ever struck any woman in my life.”
Mr Depp said at the time the accusations had “permeated” the entertainment industry and had become a “quote, unquote, fact”.
“It’s been six years of trying times, very strange when one day you’re Cinderella, so to speak, and then in 0.6 seconds you’re Quasimodo,” he said
“I didn’t deserve that, nor did my children, nor did the people who have believed in me all these years.
“I pride myself on honesty… on truth. Truth is the only thing I’m interested in.
“Lies will get you nowhere, and lies build upon lies… I’m obsessed with the truth so today is the first opportunity that I’ve been able to speak about this case in full.”
The actor also spoke about the emotional and physical abuse that he was subjected to by his mother and father during his own childhood, but said it had taught him valuable lessons about how to bring up his own children.
He said it was “diabolical” that his children had been exposed to the allegations against him at school from their peers.
Mr Depp, who wore a dark suit and light-coloured paisley tie and had his long hair tied back, is due to continue giving evidence on Wednesday.