Regarding the federal Anti-Drug Media Campaign, an independent report by Westat and the Annenberg School found that: "Overall, the results are mixed. Some positive trends in youth outcomes occurred over the period covered by NSPY, though evidence linking them to Campaign exposure is weak. In particular, the proportion of nonusing youth saying they would “definitely not” try marijuana over the next 12 months was significantly higher in 2004 than in 2002, the last year prior to the redirected Campaign, which included the Marijuana and Early Intervention Initiatives. On the other hand, the associational analyses provide no evidence to support a claim that the favorable trend in youth intentions was influenced by Campaign exposure."

Source

Hornik, R., Maklan, D., Cadell, D., Barmada, C., Jacobsohn, L., Henderson, V., Romantan, A., Niederdeppe, J., Orwin, R., Sridharan, S., Chu, A., Morin, C., Taylor. K., and Steele, D. (June 2006). Evaluation of the National Youth Anti-Drug Media Campaign: 2004 Report of Findings. Report prepared for the National Institute on Drug Abuse (Contract No. N01DA-8-5063), Washington DC: Westat.