Effects of the National Youth Anti-Drug Media Campaign on youths.
D000293:Adolescent; D000294:Adolescent Behavior; D000329:Advertising / Q000379:methods*; D001294:Attitude to Health; D002648:Child; D003430:Cross-Sectional Studies; D015438:Health Behavior; D006266:Health Education / Q000458:organization & administration*; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion / Q000458:organization & administration*; D006801:Humans; D033182:Intention; D008137:Longitudinal Studies; D008385:Marijuana Smoking / Q000009:adverse effects / Q000453:epidemiology / Q000517:prevention & control*; D008402:Mass Media; D010379:Peer Group; D015397:Program Evaluation; D000297:Psychology, Adolescent; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology