Cannabis is currently illegal in the United States at the federal level, although a number of states have decriminalized its use for both medical and recreational purposes. The primary reason why marijuana remains illegal nationally is due to the Drug Enforcement Administration’s (DEA) classification of cannabis as a Schedule I narcotic.The DEA classifies drugs, chemicals, and certain substances according to a five-tiered categorization based on two factors:The drug’s proven and acceptable medical use within the United States.The drug’s potential for dependency or abuse.The following substances are classified as Schedule I narcotics: heroin, LSD, marijuana, ecstasy, methaqualone (commonly known as “Quaaludes”), and peyote. The primary determining factor for this list is not necessarily the second factor listed above, but rather the first; this is why heroin (no acceptable medical use) is a Schedule I narcotic and cocaine (with an extensive list of medical applications) is classified as a Schedule II, or lower level, narcotic, despite both being highly addictive substances.Compared to these two drugs it becomes obvious that cannabis is not highly addictive. Consider the following chart which compares various psychoactive drugs on the basis of dependence potential and active/lethal doses. Marijuana is classified as having a “moderate/low” dependence potential, contrasted to cocaine (moderate/high) and heroin (very high).In fact, a number of legal substances, many of which do not require a prescription, offer a much higher dependency potential with fewer medical applications, such as nicotine, caffeine, and alcohol.This graph demonstrates the percentage of users who demonstrate some level of addiction to the corresponding substances:Illegal substances are indicated in red, while legal (half of which are unregulated) substances are shown in blue. All of this data confirms that cannabis is listed as a Schedule I narcotic not because of its dependency potential, but rather because of its lack of accepted medical applications within the United States. Proponents of marijuana have long pointed out the extensive potential medical applications of cannabis. The most common applications of medical marijuana include being used to treat chronic pain, reduce nausea and vomiting during chemotherapy, treating systemic muscle spasms, and improving appetite in patients with HIV/AIDS. Initial research indicates that cannabinoids could be used to treat the following conditions:CancerDementiaDiabetesEpilepsyGlaucomaTourette syndromeHuntington’s diseaseParkinson’s diseaseAmyotrophic lateral sclerosisBipolar disorderMultiple sclerosisInflammatory Bowel Disease (IBD)AnxietyDepressionPsychosisThe major inhibition to further testing of cannabis for medical applications remains the DEA’s classification of the drug as a Schedule I narcotic. Several steps must be completed to even begin research: the Food and Drug Administration (FDA) must approve the research, a license must be obtained from the DEA, and the National Institute on Drug Abuse must review and approve of any research to be conducted on cannabis. These steps are not only complicated, but are also time-consuming: while it only takes 30 days to receive a response from the FDA on research requests, a license from the DEA can take over a year to obtain. The NIDA is the only source that the federal government allows to cultivate and provide cannabis for research; marijuana is the only Schedule I narcotic with such a monopoly, and the NIDA has no deadline to respond to research requests. This presents an interesting, catch-22 scenario: drug research for medical applications is severely inhibited by the DEA’s classification, but the DEA’s classification is based primarily on the lack of proven medical applications for cannabis. Until the DEA lifts these restrictions, forward movement on legalization of cannabis at the federal level will be a slow-moving initiative at best.In the meantime, however, the federal government allows states to decriminalize marijuana as long as a regulation system exists at the state level. At the present time, Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon, and Washington have legalized marijuana for both medical and recreational use. Ironically, the District of Columbia has decriminalized cannabis for both recreational and medical purposes, but Congress currently blocks commercial recreational sale. The remainder of the states have varying stances on the criminal classification of marijuana use:Thirteen states, Puerto Rico, and Guam have legalized psychoactive medical marijuana.Thirteen states have legalized non-psychoactive medical marijuana. Twelve states have legalized medical marijuana and decriminalized recreational marijuana.One state and the US Virgin Islands have decriminalized possession.Three states and two territories prohibit the use or possession of cannabis for any purpose.Attitudes towards marijuana legalization in the United States have grown progressively more liberal. Gallup has performed polls for several decades measuring voter views; in 1969 only 16% of voters favored legalizing cannabis, but by 2005 that number had risen to 36%. As more citizens are exposed to marijuana the rate of favoring legalizing it has rapidly increased; by 2009 between 46% and 56% of American voters stated that they would support legalization. Voters tend to have a similar attitude towards federal intervention in states that have legalized or decriminalized cannabis: in a 2012 Gallup poll 64% of Americans said that they do not believe the federal government should interfere with states’ business in these matters. Not surprisingly, attitudes tend to fall along age lines: while only 36% of voters older than age 65 support legalization, those numbers steadily increase the younger the voter polled; fully 60% of 18- to 29-year-olds believe that legalization is okay.Major objections by conservative activists against the legalization of cannabis include the opinion that decriminalization will lead to higher rates of use by youth and adolescents; research, however, does not confirm this belief. In Colorado, for example, not only is teen use lower than the national average, fewer teens report trying marijuana than prior to legalization. Often the allure of a forbidden substance is what draws teens to try something new; when that mystique is removed, so is much of the temptation.What may eventually turn the tide of federal sentiment against cannabis are tax dollars. In 2013 Colorado was estimated to see $60 million in combined savings and revenue, with that number estimated to double by 2017. Approximately $15 billion worth of marijuana is sold annually in California; an excise tax could raise up to $1.3 billion per year. The movement towards a repeal of the federal ban on cannabis is gaining momentum and will likely be successful within the next decade. Until then, one can expect that state decriminalization on the use of both medical and recreational marijuana will continue at an increasing rate.