Fresh off a Tony nomination for his performance in the hit Broadway musical “The Book of Mormon,” Josh Gad is set to join the ensemble cast of Stuart Blumberg’s sex addiction pic “Thanks for Sharing.”Mark Ruffalo, Gwyneth Paltrow, Tim Robbins and Joely Richardson star in the dramatic comedy, which follows a group of unlikely friends as they try to recover from sex addiction and forge meaningful relationships. Gad will play Neil, an unrestrained sex addict with a strong appetite. He cheats his way through recovery programs until Ruffalo’s character becomes his sponsor and helps straighten him out. Blumberg makes his directorial debut with the project, which he co-wrote with Matt Winston. A co-production of Class 5 Films and Olympus Pictures, pic is being fully financed by Olympus, and starts production this month in Gotham. Leslie Urdang, Dean Vanech and Miranda de Pencier will produce for Olympus, while William Migliore and David Koplan will produce for Class 5. Blumberg’s Class 5 partner Edward Norton exec produces. Gad is repped by ICM and Brillstein Entertainment Partners.