Drug Enforcement Administration
Marijuana is a gateway drug. In drug law enforcement, rarely do we meet heroin or cocaine addicts who did not start their drug use with marijuana. Scientific studies bear out our anecdotal findings. For example, the Journal of the American Medical Association reported, based on a study of 300 sets of twins, that marijuana-using twins were four times more likely than their siblings to use cocaine and crack cocaine, and five times more likely to use hallucinogens such as LSD.