Matthew Perry has thanked his former co-star Jennifer Aniston for being the one to "reach out" and tell him that the cast of Friends "knew" he was drinking.
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The actor, who is releasing his memoir and will share details of his devastating battle with addiction, told ABC News anchor Diane Sawyer that he was "really grateful" for Jennifer's friendship.
WATCH: Matthew Perry 'really grateful' for Jennifer Aniston's friendship during height of addiction
In the trailer for their full interview, which will air on 28 October, Diane recalled how Jennifer said to Matthew: "We know you’re drinking."
Matthew then confirmed the moment, and added: "Imagine how scary a moment that was. She was the one who reached out the most, you know. I’m really grateful to her for that."
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Jennifer has remained close to Matthew, and was the first to like his social media post in October when the Chandler Bing actor shared a video featuring details of the book.
Friends, Lovers, and the Big Terrible Thing will be released on 1 November and the memoir will see Matthew delve into his time on the hit comedy, as well as his former relationships and friendships, and the devastating addictions that almost led to his death.
Friends, Lovers and the Big Terrible Thing by Matthew Perry
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In an interview with Today earlier in the year Jennifer revealed that she had no idea just how much Matthew was struggling during their time filming Friends.
She said: "I didn't understand the level of anxiety and self-torture that was put on Matthew Perry if he didn't get that laugh, and the devastation that he felt. Which makes a lot of sense."
Matthew also recently sat with People magazine and shared that during the height of Friends popularity, he thought he could handle his addiction, and there would be lengthy periods of time when he was clean. However, at one point he confesses that he was down to 128 pounds and taking 55 Vicodin a day.