This report finds that adolescent smoking, drinking, misusing prescription drugs and using illegal drugs is, by any measure, a public health problem of epidemic proportion, presenting clear and present danger to millions of America's teenagers and severe and expensive long-range consequences for the entire population. This report is a wake-up call for everyone, regardless of whether they seek to win the future by investing in the youth or seek to cut public spending to avoid a back-breaking financial burden on their children and grandchildren. The findings and recommendations in this report offer common ground and opportunity to help achieve both objectives. This report finds that: (1) Three-fourths of high school students (75.6 percent, 10.0 million) have used addictive substances including cigarettes, alcohol, marijuana or cocaine; (2) Almost half of high school students (46.1 percent, 6.1 million) are current users of these substances; and (3) Of high school students who have ever smoked a cigarette, had a drink of alcohol or used other drugs, 19.4 percent have a clinical substance use disorder, as do 33.3 percent of current users. Appendices include: (1) Methodology; (2) 2010 CASA Survey of Parents of High School Students; (3) 2010 CASA Survey of High School Students; (4) 2010 CASA Survey of High School Teachers and School Personnel; (5) Key Informant Interviewees; and (6) Screening, Brief Intervention and Referral to Treatment (SBIRT). A bibliography is included. (Contains 29 tables, 50 figures and 1452 notes.) [Funding for this paper was provided by Legacy[R] and the Michael Alan Rosen Foundation.]