Friends: Matthew Perry 'can't remember' 3 years of filming due to substance abuse

Matthew Perry has opened up further about his past. In an interview with Britain’s BBC Radio 2 on Friday, he explained that he not only struggled with addiction while on Friends, but still can’t recall much of what he filmed for several years because of it.

When asked which episode was his least favorite, Perry admitted that his substance abuse erased much of his memory of his time on set. “Oh my goodness,” he said. “I think the answer is I don’t remember three years of it. So none of those … somewhere between season 3 and 6.” The actor then added that “a little bit of the time, I was a little out of it, yeah.”

The 46-year-old has previously spoken at length about getting sober, telling People in 2013 that he abused alcohol and later prescription medication before getting clean. “I was a hopelessly narcissistic guy, and I only thought about myself, and then that just shifted,” he told the magazine at the time, “and when that happened, I got some true happiness and comfort in my life.”

Perry has most recently begun preparations for the play The End of Longing, set to debut in London in February. Though the role prevented him from joining his Friends castmates at the taping of NBC’s Must See TV: A Tribute to James Burrows, Perry will make an appearance in the special, which airs Feb. 21.