Paul Rudd Says 'There's a Reason' Shrink Next Door Costar Will Ferrell Is 'America's Sweetheart'

Paul Rudd and Will Ferrell are reuniting!

Rudd, 52, raved about working with Ferrell, 54, on The Shrink Next Door during a joint interview with his costar on Monday's episode of PEOPLE (the TV Show!).

"Anybody would love to work with Will. And there's a reason why he's America's sweetheart," Rudd told host Kay Adams of Ferrell, with whom he previously starred in the 2004 hit comedy Anchorman: The Legend of Ron Burgundy and the 2013 sequel.

The two actors star together in the upcoming Apple TV+ series The Shrink Next Door, which is based off Joe Nocera's podcast of the same name. Rudd plays Dr. Isaac "Ike" Herschkopf, while Ferrell plays his longtime patient Martin "Marty" Markowitz.

The story follows the relationship between the Manhattan psychiatrist and Markowitz, who is taken advantage of financially and isolated from his loved ones while a patient of Herschkopf's.

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In their conversation with PEOPLE (the TV Show!) Monday, Ferrell had nothing but praise for his costar.

"The biggest takeaway for me was just how great an actor Paul is," Ferrell said. "To get to kind of thread the needle between this character who is, at first, very loving and sincere as a therapist, who's really helping Marty stand up for himself and become a stronger person. And then to slowly peel that away and realize that he's got ulterior motives that are less than honorable, that's a hard performance to give. And he does it masterfully."

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Rudd mused on how he identified with one of his darkest roles yet. "I didn't really look at him as villainous, even though I think most people probably will," he said. "To me, I'm playing a person who is complex and nuanced and has his own struggles and is trying to navigate all of this."

Ferrell also recounted meeting the real Marty for research. "We kind of asked, why aren't you more ashamed about that? Why are you willing to share your story?" he said.

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"And he just thought, 'You know what? This is therapeutic for people to learn about what I went through, and hopefully, prevent anyone from experiencing the same thing," Ferrell explained.

Rudd and Ferrell star in the 10-part series alongside Kathryn Hahn as Marty's sister Phyllis and Casey Wilson as Ike's wife Bonnie.

See the Will Ferrell and Paul Rudd in The Shrink Next Door, premiering Nov. 12 on Apple TV+.