EXCLUSIVE: Amy Ryan is set to co-star opposite Gabriel Byrne on the upcoming third season of the HBO drama In Treatment. The series, based on an Israeli format, centers on Dr. Paul Weston (Byrne), a psychotherapist, and his weekly sessions with patients. Ryan will play Paul’s new therapist. In the first two seasons, he was seeing his clinical supervisor, mentor and psychotherapist Gina, played by Dianne Wiest, who is departing the show (She earned two Emmy nominations for the role and won in 2008). Oscar-nominated Ryan joins another high-profile new addition to the cast of In Treatment next season, Debra Winger, who will play one of Paul’s patients, a formerly big star in an anxiety crisis about her career. This marks Ryan’s return to HBO where she co-starred on The Wire. Gersh-repped Ryan, who also recurred on The Office, most recently co-starred opposite Matt Damon in Green Zone.