April 2014 Almost one-third (32 percent) of the roughly 42,000 Monitoring the Future survey respondents reported having used marijuana during their lifetime. However, abuse of many other drugs—methamphetamine, heroin, cocaine, and some prescription medications—declined.
Researchers used the statistical technique of latent class analysis to describe distinct patterns of marijuana use across age using data from nearly 10,000 participants in the Monitoring the Future study. Longer-term marijuana use (extending from age 18 into the late 20s or beyond) was associated with increased risk of self-reported health problems at age 50.
July 2013 Researchers found that 1 in 8 high school seniors had used a prescription opioid nonmedically, and 70 percent of these teens had compounded the attendant risk by co-ingesting an opioid with one or more other drugs. Nonmedical opioid use was significantly more prevalent among whites than among African Americans or Hispanics.