Question: What is the current usage level of illicit drugs by American youth?
Answer: The cited reference notes “Youth are especially vulnerable to drug abuse. According to NIDA, young Americans engaged in extraordinary levels of illicit drug use in the last third of the twentieth century. Today, about 47% of young people have used an illicit drug by the time they leave high school and about 16 percent of eighth, tenth, and twelfth graders are current (within the past month) users. (https://www.dea.gov/pr/multimedia-library/publications/drug_of_abuse.pdf; accessed May 2017)