According to the 2009 National Survey on Drug Use and Health (NSDUH), sponsored by SAMHSA, illicit drug in the USA has risen to its highest level in 8 years. In 2009, about 8.7 percent of Americans aged 12 and older said they used illicit drugs in the month prior to the survey and this is 9 percent increase over the 2008 rate.

This increase is mainly driven by the increase in the use of marijuana which rose to 6.6 percent in 2009. This increase was due to excess use of marijuana in children aged between 12 to 17 and young adults aged between 18 to 25. Marijuana is the most commonly used illicit drug and about three quarters of those who use illicit drugs also use marijuana. This reversed the trends in the use of marijuana and since past few years there is a growing percentage of youth who are using the drugs.

2009 saw an increase in the use of prescription drugs and the less frequently used methamphetamine and ecstasy. Non medical use of prescription drugs rose by 12 percent. Abuse of methamphetamine increased slightly from 0.1 percent to 0.2 percent, and ecstasy from 0.2 percent to 0.3 percent.

The survey also found that drug abuse among the persons aged 50 to 59 doubled to 6.2 percent from 2.7 percent in 2002. Only about 11 percent of those who need treatment for drug or alcohol abuse received therapy in a specialty facility.