In regards to marijuana, 55.9% of middle schoolers and only 24.7% of high schoolers perceived danger in its use once or twice a week (Florida Department of Children and Families, 2004).
Approximately 3 out of every 4 high schoolers associate no risk in using marijuana once or twice a week which is interesting because only 18% of high schoolers reported using marijuana in the past 30 days.
Marijuana is the most commonly used illicit drug in the United States. Its use is widespread among young people. In 2015, more than 11 million young adults ages 18 to 25 used marijuana in the past year.
NIH Research on Marijuana: https://www.drugabuse.gov/publications/drugfacts/marijuana