Joseph Gordon-Levitt
Adam Lerner

Seth Rogen
Kyle Hirons

Anna Kendrick
Katherine McKay

Bryce Dallas Howard
Rachael

Philip Baker Hall
Alan

Serge Houde
Richard Lerner

Andrew Airlie
Dr. Ross

Matt Frewer
Mitch

Peter Kelamis
Phil

Jessica Parker Kennedy
Jackie

Anjelica Huston
Diane Lerner

Sugar Lyn Beard
Susan

Donna Yamamoto
Dr. Walderson

Yee Jee Tso
Dr. Lee

Sarah Smyth
Jenny

Daniel Bacon
Dr. Phillips

P. Lynn Johnson
Bernie

Laura Bertram
Claire

Matty Finochio
Ted

Marie Avgeropoulos
Allison

Luisa d'Oliveira
Agabelle Loogenburgen

Veena Sood
Nurse Stewart

Andrea Brooks
Attractive Woman #2

Beatrice King
Pretty Girl

Chilton Crane
Mother on the Bus

Lauren Miller Rogen
Bodie

Jason Vaisvila
Cute Guy with Dreads

Brent Sheppard
Minister

Stephanie Belding
Friendly Nurse

Ryan W. Smith
Joe

William 'Big Sleeps' Stewart
George

Amitai Marmorstein
Young Person on the Bus

Will Reiser
Greg

Christopher De-Schuster
Art Gallery Patron

Adrian Glynn McMorran
Bartender

Richard C. Burton
Thom the Patient

Susan De West
Bar Girl

Stephen Colbert
Self (archive footage) (uncredited)

D. C. Douglas
Live Volcano Reporter (voice) (uncredited)