Smith teamed with the Knocked Up funnyman to shoot the film, which centred on two pals aiming to ease their financial woes by breaking into the adult movie market.
The controversially-titled film flopped at the box office and left critics cold - and Smith was plunged into a deep depression as he feared he had torpedoed Rogen's budding Hollywood career.
He tells Britain's The Guardian, "I felt so f**king terrible. I thought I'd ruined Seth's career; it was just depressing. It forced me into seclusion, I stayed offline and ended up smoking weed and watching a lot of hockey documentaries."