Courteney Cox says Friends co-star Matthew Perry put enormous pressure on himself to be funny while filming scenes as sarcastic Chandler Bing.
The actors became household names thanks to their respective roles as Monica Gellar and Bing in the iconic 90s sitcom about five twenty-somethings living together in New York City.
And Cox, 57, believes her former co-star felt obligated to make the studio audience laugh every time the cameras were rolling.
She told The Sunday Times: "That was a lot of pressure he put on himself. That's a lot to think how much he relied on that for his own self-worth."
Cox last year reunited with cast-mates Perry, David Schwimmer, Jennifer Aniston, Matt LeBlanc, and Lisa Kudrow for highly-anticipated Friends reunion special, titled The One Where They Get Back Together.
But 52-year-old Perry - who has been open about his past battle with prescription drugs and alcohol - prompted concerns from fans after appearing to slur his speech throughout the reunion.
Cox added: "He's just struggled for a while. I think he's doing great now."
In the past, Perry has been open about alcoholism and addiction, telling People in 2002 of his use of Vicodin: "It wasn't my intention to have a problem with it. But from the start, I liked how it made me feel and I wanted to get more."
Then in 2016, Perry admitted he didn't remember filming some of the Friends seasons. "I don't remember three years of it," Perry told BBC. "I was a little out of it at the time — somewhere between seasons three and six."
Elsewhere in her interview with The Sunday Times, Cox admitted she loved reuniting with her former co-stars and insisted she will never get bored with discussing her time on the show.
"No, that was such a huge part of my life," she said. "It was such a lucky situation that I fell into the show, and I went through so many things in those 10 years."
Of her relationship with her co-stars, she added: "We're just really comfortable. We've shared so much history together and we laugh. Lisa's laugh alone is the most infectious laugh I've ever heard. It's adorable. We have deep conversations, we also have silly times."
