Megan Fox
Jennifer
Amanda Seyfried
Needy
Johnny Simmons
Chip
Adam Brody
Nikolai
Sal Cortez
Chas
Ryan Levine
Mick
Juan Riedinger
Dirk
Colin Askey
Keyboardist
Chris Pratt
Roman Duda
Juno Rinaldi
Officer Warzak
Kyle Gallner
Colin Gray
Josh Emerson
Jonas Kozelle
J.K. Simmons
Mr. Wroblewski
Amy Sedaris
Needy's Mom
Cynthia Stevenson
Chip's Mom
Nicole Leduc
Camille
Aman Johal
Ahmet from India
Dan Joffre
Raymundo
Candus Churchill
Nutritionist
Carrie Genzel
Jennifer's Mom
Emma Gallello
Little Jennifer
Megan Charpentier
Little Needy
Jeremy Schuetze
Craig
Valerie Tian
Chastity
Emily Tennant
Gossiping Girl
Karissa Tynes
Other Girl
Eve Harlow
Goth Girl
Michael Brock
Goth Boy
Genevieve Buechner
Goth Girl #2
Adrian Hough
Colin's Dad
Gabrielle Rose
Colin's Mom
Michael Bean
Priest
Bill Fagerbakke
Jonas' Dad
Marilyn Norry
Jonas' Mom
Cut Chemist
DJ at Dance
Zoe LaLiberté
Candlelight Vigil Singer
Chelsey Smith
Candlelight Vigil Singer
Whitney Chow
Candlelight Vigil Singer
Michael Orstad
Candlelight Vigil Singer
Ronnie Robinson
Orderly
Ed Anders
Orderly
Roxanne Wong
Patient #1
Diane Dutra
Patient #2
Maya Toews
The Creepy Hand
Diablo Cody
Melody Lane Drinking Woman (uncredited)
Lance Henriksen
Passing Motorist (uncredited)