Regarding exposure to ONDCP's National Anti-Drug Media Campaign and marijuana use by 12-18 year olds, a report prepared for NIDA by Westat and the Annenberg School of Communication determined: "In sum, the data do not support claims of favorable Campaign influence on any of the four original cognitive outcomes.

"Westat's analysis of the relationship between exposure to campaign advertisements and youth self-reported drug use in the NSPY [National Survey of Parents and Youth] data for the entire period covered by its evaluation -- assessments that used statistical methods to adjust for individual differences and control for other factors that could explain changes in self-reported drug use -- showed no significant effects of exposure to the campaign on initiation of marijuana by prior nonusing youth.