Michael Sheen

Dr. Slavkin O'Hara

Toni Collette

Patricia Herman

Jason Spevack

Henry James Herman

Samantha Weinstein

Audrey O'Hara

Melyssa Ade

Kindergarten Teacher

Oprah Winfrey

Oprah

Frank Moore

Stan Herman

Paul Braunstein

Dr. Gunther Flowers

Hannah Brigden

Young Patricia Herman

Sarah Orenstein

Mother Herman

Jamie Johnston

Young Billy Herman

Mark MacDonald

Tim Herman

Mickey MacDonald

Tom Herman

Cameron Kennedy

Jimmy Herman

Kate Hewlett

Alice O'Hara

Kevin Hare

Delivery Room Doctor

Austin Macdonald

Brian the Bully

Mishu Vellani

Miss Abda

Aaron Abrams

Malcom's Dad / Nurse Stewart