Despite a degree of continued controversy, medical cannabis appears to be here to stay as a part of the armamentaria of physicians treating chronic pain. With the recent election, Massachusetts became the 18th state (in addition to the District of Columbia) to legalize cannabis for medical purposes. Although not everyone in the pain community has accepted cannabis as a viable form of treatment for chronic pain, the number of states allowing physicians to “prescribe” cannabis is increasing, with progressively more physicians considering treatment with cannabinoids a viable and safer alternative to much-maligned chronic opioid therapy, ^[1] despite concerns among some providers that the efficacy and safety of medical cannabis have not yet been adequately evaluated. ^[2] Although many physicians recognize the benefits of medical cannabis for purposes of pain management and a number of studies ^[3-6] have supported this efficacy, physician supporters of medical cannabis still often question the risk-benefit ratio as well as the strength of the evidence base of this approach to pain management. ^[7]

Medical use of cannabis has been legally controversial since California became the first state to allow its use for medical purposes with the passage of Proposition 215 in 1996. Its use still represents a violation of the Controlled Substances Act, which classifies it as Schedule 1 substance (ie, having high potential for dependence with no “accepted” medical use). ^[8] Cannabis has remained a Schedule 1 drug despite calls by the American Medical Association, the Institute of Medicine, and the American College of Physicians to reschedule it. ^[9] Notwithstanding being federally illegal, there were only limited challenges to the use of medicinal cannabis immediately following the passage of Proposition 215. However, with the George W. Bush administration, the federal government’s stance and behavior regarding medical cannabis changed drastically. While the Clinton administration, for the most part, assumed the position that the Controlled Substances Act did not apply to Schedule 1 drugs such as marijuana in states with medical marijuana laws in place, the Bush administration chose to eliminate its predecessor’s exception for medical use. ^[10]

Despite 2000 campaign claims that medical marijuana laws ought to be determined by individual states, the Bush administration aggressively suppressed states’ rights regarding this issue. Within Bush’s first year as president, the federal Drug Enforcement Administration (DEA) seized medical records of cannabis-using patients in California, destroyed the marijuana gardens of cancer and AIDS patients, and closed dispensaries providing medicinal cannabis to thousands of patients. ^[11] In September 2002, 30 DEA agents armed with M-16s burst into a medical marijuana hospice in Santa Cruz, California, and arrested its owners and a wheelchair-bound polio patient, thereby increasing the contention between the Bush administration and state leaders. ^[12] A month prior to the Santa Cruz raid, the DEA raided the home of Diane Monson, a California woman suffering from chronic low back pain due to a degenerative disease, and confiscated and destroyed 6 marijuana plants. Ms. Monson and Angel Raich, a California woman suffering from a malignant brain tumor who also used medical marijuana, then brought suit to prevent future raids. Although they lost their case, the Ninth Circuit Court of Appeals ruled in their favor. In (US Attorney General) Gonzalez v Raich, however, the US Supreme Court reversed the Appeals decision, stating that Congress has the right to “criminalize the private possession and medicinal use of cannabis, even on a licensed physician’s recommendation and under the protection of state law.” ^[13]

While campaigning for the Presidency in 2008, Barack Obama indicated that he did not support the use of federal resources as a means of circumventing individual states’ medical cannabis laws. ^[14] Within 2 months of President Obama’s inauguration, his newly appointed Attorney General, Eric Holder, announced that the administration would only pursue those who attempted to use state medical marijuana laws as a shield in order to pursue activities inconsistent with the intention of the state laws. ^[14] In October 2009, Holder appeared even more strongly in favor of medical cannabis rights when he acknowledged that although state programs violated federal law, pursuit of caregivers and patients compliant with the state laws would be given low priority. ^[15] However, the Department of Justice’s “nonenforcement policy” has not necessarily been consistently applied. While the number of dispensary raids has decreased markedly since the era of the Bush Department of Justice, raids still do occur. A rash of dispensary raids by the DEA in 2011 and 2012 has left state governments as well as suppliers and users of medical marijuana confused and angry. ^[16,17] In fact, over the past year, federal authorities shut down over 600 dispensaries in California alone. ^[18] Despite the increasing number of states permitting the sale and use of marijuana for patients under a physician’s care, the status of medical cannabis in the United States was, at best, somewhat perplexing even prior to the November 6, 2012 elections.