"A well-designed and executed multiyear study of the impact of the ONDCP [Office of National Drug Control Policy] anti-drug media campaign on teen initiation of drug use, or cessation of drug use, shows disappointing results for the campaign. The study provides no evidence that the campaign had a positive effect in relation to teen drug use, and shows some indications of a negative impact."

Source

General Accountability Office. "ONDCP Media Campaign - National Evaluation Did Not Find That the Youth Anti-Drug Media Campaign Was Effective in Reducing Youth Drug Use," (Washington, DC: report to the Chairman and Ranking Member, Subcommittee on Transportation, Treasury, the Judiciary, Housing and Urban Development, and Related Agencies, Committee on Appropriations, U.S. Senate, August 2006), GAO-06-818, p. 42.
http://www.gao.gov/new.items/…