Marijuana use among American adolescents has been increasing gradually over
the past two years (three years among 12th graders) following years of declining use, according to the
latest Monitoring the Future study, which has been tracking drug use among U.S. teens since 1975.
The proportion of young people using any illicit drug is also up slightly over the past two years. This
measure is driven largely by marijuana use, because marijuana is the most widely used of all illicit drugs.
In 2009, marijuana use in the prior 12 months (annual prevalence) was reported by about 12 percent of
the nation’s 8th graders, 27 percent of 10th graders, and a third of 12th graders. The proportions saying they
used any illicit drug in the past year were 15 percent, 29 percent, and 37 percent.
It has been a known fact over the last 20 years that the THC content in marijuana has increased, and this combination has lead to more people, young and old alike, seeking a drug rehab center for marijuana addiction.