The HBO series depicts the weekly therapy sessions of psychotherapist Paul Weston, portrayed by Byrne. Each night of the week is dedicated to one session with one of five main characters. Two-time Oscar winner Dianne Wiest, currently on Broadway in the revival of Arthur Miller's All My Sons, appears regularly as the therapist for Byrne's character.

According to the Hollywood reporter, Davis, who will be seen in the screen adaptation of Proof, will appear as a high-powered malpractice lawyer who blames Weston for her own single and childless status. Davis' Broadway credits include Ivanov and Two Shakespearean Actors.

Recent Prelude to a Kiss actor Mahoney, best known for his television role on "Frasier," has been cast as a CEO whose life is getting away from him.

Playwright Warren Leight serves as a writer for the second season, which is produced by Rodrigo Garcia, Stephen Levinson and Mark Wahlberg.

For more information visit HBO.com.