Sosie Bacon as Rose Cotter

Kyle Gallner as Joel

Jessie T. Usher as Trevor

Robin Weigert as Dr. Madeline Northcott

Caitlin Stasey as Laura Weaver

Kal Penn as Dr. Morgan Desai

Rob Morgan as Robert Talley

Gillian Zinser as Holly

Judy Reyes as Victoria Munoz

Jack Sochet as Carl Renken

Nick Arapoglou as Greg

Perry Strong as Detective Buckley

Matthew Lamb as Jackson

Dora Kiss as Mom

Meghan Brown Pratt as 10 Year Old Rose

Jared Johnston as Orderly Dan

Ura Yoana Sánchez as Nurse Wanda

Vanessa Cozart as Nurse

Shu Q as Officer Chan

Shevy Gutierrez as Officer Wilkes

Sara Kapner as Stephanie

Steven Strickland as Deputy Sheriff

Kevin Keppy as Nightmare Mom

Marti Matulis as The Monstruosity

Scot Teller as Prison Guard (uncredited)

Setty Brosevelt as Driver / Pedestrian (uncredited)

Jerry Lobrow as Cocktail Party Guest (uncredited)

Nadia Ramdass as Nurse (uncredited)

Rachel Yong as Brash Colleague (uncredited)

Felix Melendez Jr. as Gabriel Munoz (uncredited)

Elaine Apruzzese as Psychiatric Patient (uncredited)

Shanea Lattimore as Drug Party Girl (uncredited)

Anne Schmalzigan as Angela Powell (uncredited)