Decreases in Marijuana Use
"The NSPY [National Survey of Parents and Youth] did not find significant reductions in marijuana use either leading up to or after the Marijuana campaign for youth 12 to 18 years old between 2002 and 2003. Indeed there was evidence for an increase in past month and past year use among the target audience of 14- to 16-year-olds, although it appears that the increase was already in place in the last half of 2002, before the launch of the Marijuana Initiative. It will be worthwhile to track whether the nonsignificant decline from the second half of 2002 through the first half of 2003 is the beginning of a true trend. There was a significant decrease in lifetime marijuana use among youth 16 to 18 years of age from 2002 to 2003; however, since this significant decrease was not replicated in either the directly relevant past year or past month time periods, it is difficult to ascribe the change to the campaign."
Hornik, Robert, David Maklan, Diane Cadell, Carlin Henry Barmada, Lela Jacobsohn, Vani R. Henderson, Anca Romantan, Jeffrey Niederdeppe, Robert Orwin, Sanjeev Sridharan, Adam Chu, Carol Morin, Kristie Taylor, Diane Steele, "Evaluation of the National Youth Anti-Drug Media Campaign: 2003 Report of Findings," Delivered to National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services By Westat & the Annenberg School for Communication, Contract No. N01DA-8-5063, December 22, 2003, p. 4-15.