TABLE 1.

Research Design, Anti-Drug Ads used in Each Condition, and Description of Anti-Drug Ads

Condition (N)	Ad	Description of ad
Control (n =143)	None	N/A
Gateway (n =141)	Bathroom	Commercial-style song about ’meth’ (methamphetamine) is played while showing skinny girl who cleans bathroom and herself in a paranoid manner, then wastes away. Lyrics to song cynically tell about how she has so much energy, doesn’t need to sleep or eat, just has to get those hairs out of her face, and bugs out of her place. She needs one more hit, no time to waste.
	Roaches	A teenage boy with sores on his face lies trembling on a bed. Roaches crawl on his face. Voice-over says, “This is what it’s like to be hooked on meth: Paranoid, hallucinating, schizophrenic. Sweet dreams”.
	Teeth	Black-and-white clip shows girl looking in mirror. Pretty at first, she takes off make-up, false eyelashes, and finally her teeth. Final looks are appalling. Ends with text: “It’s hard to face what heroin can do to you”.
	Lab rats	Black-and-white clip shows laboratory rat in cage eating something. Voice-over says, “Only one drug is so addictive that 9 out of 10 lab rats use it, again and again, until dead. It’s called cocaine and it can do the same to you”. The rat is shown dying.
	Gateway	Testimonial of teenage girl who says that her first drug was pot. She further says, “I thought I’d never have a real problem with it, just hang out with my friends and use it. But then I’d use it by myself, need more, and it was like a doorway. Cause once I started it wasn’t enough, and I’d use more, and I also smoked crack, hash, angle dust, everything. I never thought I’d be like that. I was stupid, you have to think about the consequences.”
Implicit gateway (n =71)	Roaches Teeth	See Gateway condition for description
	Michael	A young man and his friends play Russian roulette while smoking pot. He loses. He’s then shown in his wheelchair. He is paralyzed on one side and takes medication every day to stop his convulsions. He says, “I found out that on weed I can’t think straight. I only smoked [pot] for a few months, but now I’m on drugs for life.”
	Surgeon	Giggling surgeon draws on joint and asks teenage boy if he has tonsillitis. The shocked boy replies in vain that he has appendicitis. Voice-over says, “What if a joint would be in somebody else’s hand. Like your surgeon, your lawyer, or your local policeman. Would you still say, marijuana is harmless?” Ends with surgeon giggling that he wants to see if he can still make a straight line with his scalpel.
Hard drug (n =63)	Bathroom Roaches Teeth Lab rats	See Gateway condition for description