The National Survey on Drug Use and Health (NSDUH) included 9 categories of illicit drugs which includes use of marijuana, cocaine, heroin, hallucinogens, and inhalants and the non medical use of prescription type pain relievers, tranquilizers, stimulants, and sedatives. In this survey, hashish is included with marijuana, and crack is considered as a form of cocaine. LSD, PCP, peyote, mescaline, psilocybin mushrooms, and ecstasy are included under hallucinogens. Inhalants includes nitrous oxide, amyl nitrite, cleaning fluids, gasoline, spray paint, other aerosol sprays, and glue.
In United States an estimated 21.8 million Americans aged 12 or older were current users of illicit drugs in 2009. It means that 8.7 percent of the population aged 12 or older are users of illicit drugs. This rate was higher than the rate in 2008.
In 2009, marijuana was the most commonly abused illicit drug and was used by 76.6 percent of current illicit drug users. 42 percent of the illicit drug users abused drugs other than marijuana. Current use of other drugs but not marijuana was reported by 23.4 percent of illicit drug users, and 18.6 percent used both marijuana and other drugs. The estimated number and percentage of persons aged 12 or older who used cocaine in the past month in 2009 were similar to those in 2008. Hallucinogens were used in the past month by 1.3 million persons aged 12 or older in 2009, including 760,000 who had used Ecstasy.
Number of the non medical users of psycho therapeutic drugs in 2009 were higher than in 2008. Statistically significant increases in the percentage using stimulants and sedatives contributed to this increase. Number of non medical users of stimulants increased from 904,000 in 2008 to 1.3 million in 2009. The number of past month methamphetamine users increased from 314,000 in 2008 to 502,000 in 2009. Rates for any psycho therapeutic drug use in 2009 were similar to those in 2007.