The actor is suing U.K. tabloid The Sun, its publisher, News Group Newspapers (NGN), and its executive editor, Dan Wootton, over a 2018 article which referred to him as a "wife-beater" in relation to domestic violence allegations made by Heard, which Depp has repeatedly denied.
According to the Press Association, the "Pirates of the Caribbean" star was questioned strongly in the witness box during Thursday's proceedings by NGN's lawyer, Sasha Wass, and admitted having blackouts but denied being violent towards his ex.
"I may have done things that I have no memory of," Depp said and added. "I am certainly not a violent person, especially with women."
He explained, "There were blackouts, sure, but in any blackout there are snippets of memory," but described Heard's claims he was violent towards her as "porkie pies (lies)" during his evidence. He did, however, acknowledge striking objects, saying, "I would rather express my anger by hitting an inanimate object than... the person I love."
Wass alleged he had pushed Heard during an attempt to stop using the opioid Roxicodone on his private island in the Bahamas in 2014, but admitted Heard's claim that he was "flipping" and "screaming" might be correct but said he was "not in any condition" to "push or attack" the "Aquaman" star.
"I remember that I was in a great deal of pain and uncontrollable spasms and such," he explained. "So flipping could be a word that was correct," he said. "I was not in good shape. It was the lowest point I believe I've ever been in in my life."
It was also revealed that the Hollywood superstar had texted Heard's mother Paige, praising her daughter for taking care of him and saving his life by helping him battle his addictions.
"What you do need to know is that your daughter has risen far above the nightmarish task of taking care of this poor old junkie," the court was told he wrote in the text.
"It was an exercise of monumental patience and instinct. I wouldn't be alive, sweetheart," he reportedly added. Depp explained the messages as coming from his desire to say good things about a daughter to her mother and has accused his ex-wife of withholding his medication.
The star has called Heard's allegations he was violent towards her during their marriage, which lasted from 2015 to 2017, a "hoax" and an "insurance policy." The trial, which began on Tuesday, is expected to last three weeks - with Depp's exes Winona Ryder and Vanessa Paradis both expected to give evidence.