The gang goes into therapy together on It's Always Sunny in Philadelphia. "The Gang Gets Analyzed" is the fifth episode of the show's eighth season.

It's Always Sunny in Philadelphia Season 8 Episode 5 Quotes

Frank: I opened up to a therapist just once. I was a kid. I got into a fight. The doctor asked me question after question, got me so scrambled up. Next thing I know, I was shanghai'd upstate to a nitwit school. You know what a nitwit school is?
Therapist: I assume you mean a school for the mentally disabled.
Frank (spits pistachio shell): Yeah, not just for nuts in the head, but bodies, too. Back then science was real crude, they stuck us all together. My roommate was a frog-kid. You ever see a frog-kid?

Mac: I gained and lost 60 pounds in 3 months.
Therapist: That's almost impossible.
Mac: Well, through God all things are possible, so jot that down.