What is clear is that cannabis impairs cognition and psychomotor responses. Numerous studies show that it lengthens a person’s reaction time and impairs his or her attention, concentration, short-term memory, and assessment of risks. These changes in psychomotor performance can last longer than the feeling of being high. Trials with licensed pilots found that marijuana impaired performance on a flight simulator for up to twenty-four hours.13 Further, most of the pilots were unaware that their performance was still impaired a day later. Several studies demonstrate associations between cannabis and collisions: drivers who use it are estimated to be some two to seven times more likely to be responsible for accidents compared to drivers not using drugs or alcohol.14
The American Psychiatric Association, in the new DSM-5, has defined a diagnosis of “cannabis use disorder.” These people had a repeated pattern of use with harmful consequences, such as inability to fulfill major responsibilities at work and persistent social problems at home. Both the DSM-5 and the World Health Organization’s International Classification of Diseases 10th edition (ICD-10) also include a list of possible symptoms of withdrawal from using cannabis: significant fatigue, sleepiness, psychomotor retardation, anxiety, and depression.15 Yet there is fierce argument about whether marijuana is addictive. Proponents of cannabis doubt that it can cause true addiction, a physiological condition with compulsive craving and use despite harm; they argue that any dependence is less significant than that seen with alcohol. Opponents of cannabis use, particularly those from the National Institutes of Health, affirm both dependence and addiction as real risks, although at a much lower percentage than that seen with cocaine or heroin.16
A New Leaf is a detailed account of the history of the regulation of cannabis, presenting in a blow-by-blow manner the legal and political battles around its prohibition. It opens on a celebratory note, with the legalization of marijuana for recreational use in two states:
Another prohibition is ending. On November 6, 2012, voters in Colorado and Washington were the first in the world to successfully challenge nearly a century of bad policy and misconceptions about cannabis.
In downtown Seattle, the Hotel Ändra was dressed white and blue, the team colors of Washington State’s…campaign….
Around 7 p.m., the owner of one of the largest and most successful medical cannabis dispensaries in the country arrived. Steve DeAngelo was unmistakable even in a crowd, with his signature long, tight pigtail braids and dark fedora…. Earlier that year, he was the star of his own Discovery Channel show, Weed Wars. His two Harborside Health Centers are in the Bay Area, but he had a soft spot for Seattle. Just a few months before, he had spoken at Seattle’s well-known Hempfest, attended by tens of thousands each year. “I’ve been working on this issue for my entire life…. And I know tonight…that there’s going to be a whole lot of angels dancing in heaven,” DeAngelo said, his eyes flooding.
The authors describe a similar scene in Denver:
Brian Vincente, a lawyer who advocated for medical cannabis in Colorado for nearly a decade,… took the stage. “Tonight we made history. This is something you’re going to tell your kids about,” Vincente said. “Marijuana prohibition started in 1937. The first person arrested was in Colorado.” The crowd booed. “Colorado fucking turned this thing around tonight.” And with the f-word came gaiety.
These successes resulted from a unique effort joining groups from the ends of the political spectrum:
The support of conservative Republicans and Libertarians was as important to the Colorado…campaign as that of Democrats and liberals…. The swing state of Colorado, birthplace of the Libertarian party, is decidedly purple. The Libertarian Party of Colorado emphatically endorsed Amendment 64 in May, for example, while the Colorado Democratic Party offered support but stopped short of an endorsement. The Republican Liberty Caucus of Colorado also endorsed the amendment because prohibition is “inconsistent with Republican values,” which call for more “personal responsibility” and less “federal overreach.”
Recent articles in The New Yorker17 and The Nation18 describe in a succinct and focused way the political terrain around cannabis legalization for medicinal or recreational use in the United States. The New Yorker article features Professor Mark Kleiman, a drug policy expert at the University of California, Los Angeles, who sees legalization through the perspective of a scientist, who regards it as a kind of ongoing experiment. Legalization will test a group of hypotheses about public policy, and he suspends conclusions until more data are available.
As with every social initiative, there could be negative effects and Kleiman advocates close monitoring of excessive use among adolescents and of driving under the influence when cannabis is legal for recreational use. He “appears,” according to the New Yorker article, “to derive grim pleasure from informing politicians that they have underestimated the complexity of a problem.” One major concern is that when legal marijuana goes on sale in Washington State this spring, the current black market will not disappear; rather, legal over-the-counter marijuana will be competing with illicit sources. Kleiman argues that to support the legal market, there should be even greater law enforcement pressure on those who do not respect the rules. In Washington, few in government wanted to hear such a proposal.
Similarly, Kleiman is not confident that alcohol will become less appealing as marijuana is made available. While he acknowledges that alcohol is the greater danger of the two, he raises the possibility that cannabis will be used to complement drinking. Finally, he says that in the “Manichaean world of politics,” the pendulum may swing from marijuana as illegal—with sale or use of it causing imprisonment—to “going all the way to ‘We should sell it like cornflakes.’”
Unlike the cautious New Yorker piece, the articles in The Nation offer a robust endorsement of legalization. The cover of the magazine displays a photograph of a young Barack Obama flashing the V for victory sign with friends in high school clustered around the logo of the “Choom Gang.” An accompanying editorial by Katrina vanden Heuvel notes that recent presidents, including Bill Clinton, George W. Bush, and Barack Obama, all “have more or less owned up to breaking America’s drug laws” through possession or use of cannabis; if they had been observed by the police, they might well have been incarcerated, with no hope of a career leading to the White House. A New Leaf emphasizes the risks of arrest for possession. Racial discrimination, with disproportionate numbers of African-Americans arrested, is one ugly reality of prohibition:
While cannabis users who are arrested are not often sent to prison, there are still more than twenty thousand people incarcerated for mere possession. According to a comprehensive 2013 report released by the ACLU, between 2001 and 2010 more than 8 million cannabis arrests were made in the United States (88 percent for possession), and the possession enforcement alone cost more than $3.6 million in 2010.
Across the country, blacks are nearly four times more likely than whites to be arrested for cannabis possession, despite comparable rates of use; in some counties that number increases from four to thirty. Finally, 62 percent of those arrested are twenty-four or younger, which means their arrest records will follow them throughout adulthood.
All of these wasted hours, dollars, and arrests are a distraction from hard drug use and trafficking:
Again, when cannabis—which accounts for 80 percent of all illegal substance use in the United States—is removed from the drug war picture, the country can more effectively discuss and implement a new and more fitting public health approach for the remaining hard drugs.
Several years ago, I consulted on the case of a young woman with anemia. Her internist had made an exhaustive evaluation of her condition but had found no cause for it. The patient had been under a great deal of stress at work, and when I asked how she dealt with this, she said she had been smoking marijuana every night. A bone marrow examination showed reduced numbers of cells, not severe enough to be classified as aplastic anemia, but certainly abnormal in a woman in her twenties. The numerous components of cannabis are not known to be toxic to blood cells; marijuana smoking has not been reported as a cause of anemia. But I recalled that some of the illicit crops had been sprayed with toxins that might have deleterious effects on blood cell development.
So together we decided that she would suspend smoking, and over a period of months her anemia was resolved. A subsequent bone marrow examination showed full restoration of normal blood cell numbers. This was not definitive proof, but it certainly suggested that something in the grass she got from a dealer was the potential culprit. If there is not adequate oversight of the marijuana on sale, those seeking street cannabis could be exposed to dangerous contaminants.
In a forthcoming book, Weed Land, Peter Hecht, a journalist at The Sacramento Bee, charts the evolution of California’s medical marijuana law, the first in the nation.19 Much of the momentum behind its passage came from a joining of forces between AIDS activists and academic physicians like Donald Abrams at San Francisco General Hospital, who demonstrated the clinical benefits of augmented appetite and relief of pain in patients with cachexia from HIV. Medical marijuana, now legal in twenty states and the District of Columbia, is regulated like a supplement rather than a drug. There is no standardization of optimal amounts of psychoactive THC and nonpsychoactive CBD, although they must be free of toxins. (A British company, GW Pharmaceuticals, makes Sativex, an oral spray containing extracts of two standardized cannabis strains that are mixed to give exact doses of THC and CBD. Sativex was approved in several countries, but not in the United States.)
For a physician like myself prescribing a therapy, this is an uncomfortable situation, because a prescription should be exact in specifying how much drug is delivered. Further, side effects may occur in patients taking multiple other medications, due to so-called “drug-drug interactions.” Such interactions have not been well studied with THC and CBD, in part because of the restriction of access to the plant for the clinical research community. Scientists in my laboratory studied pure chemicals, THC and CBD, under strict federal oversight; we purchased the cannabinoids from chemical companies that used quality control. As Martin and Rashidian note, clinical study of the plant itself, with its scores of active chemicals, is another matter:
The federal government has imposed additional and unique restrictions on cannabis research, with little rationale—beyond politics. The federal government has enabled only one institution, the University of Mississippi, to legally grow cannabis for research on its behalf, although it is free to award additional and alternative contracts. And cannabis is the only research substance for which the government is the sole supplier. For a scientist to receive cannabis from the federal farm at the University of Mississippi, a trifecta of approvals…must be obtained from the FDA, DEA, and a Public Health Service panel.
Perhaps as states legalize marijuana, this barrier to research will be lowered, as it was for stem cell research, once restricted by federal law. And as more studies are conducted on marijuana for medical or recreational uses, opponents and enthusiasts may both discover that they were neither entirely right nor entirely wrong.
13 V.O. Leirer, J.A. Yesavage, and D.G. Morrow, “Marijuana Carry-Over Effects on Aircraft Pilot Performance,” Aviation, Space, and Environmental Medicine, Vol. 62, No. 3 (1991); D.G. Newman (Australian Government, Australian Transport Safety Bureau), “Cannabis and Its Effects on Pilot Performance and Flight Safety: A Review” (2004). ↩
14 M. Asbridge, J.A. Hayden, and J.L. Cartwright, “Acute Cannabis Consumption and Motor Vehicle Collision Risk: Systematic Review of Observational Studies,” BMJ, Vol. 344, No. 14 (2012). ↩
15 D.S. Hasin, K.M. Keyes, D. Alderson et al., “Cannabis Withdrawal in the United States: Results from NESARC,” Journal of Clinical Psychiatry, Vol. 69, No. 9 (2008). ↩
16 See Baker et al., “The Therapeutic Potential of Cannabis,” and Foreman, A Nation in Pain. ↩
17 Patrick Radden Keefe, “Buzzkill,” The New Yorker, November 18, 2013. ↩
18 Katrina vanden Heuvel, “Why It’s Always Been Time to Legalize Pot,” and other articles in The Nation ’s “Special Issue: Marijuana Wars,” November 18, 2013. ↩
19 Peter Hecht, Weed Land: Inside America’s Marijuana Epicenter and How Pot Went Legit (University of California Press, May 2014). ↩
Pot and the Myth of Shen Nung March 20, 2014
V.O. Leirer, J.A. Yesavage, and D.G. Morrow, “Marijuana Carry-Over Effects on Aircraft Pilot Performance,” Aviation, Space, and Environmental Medicine, Vol. 62, No. 3 (1991); D.G. Newman (Australian Government, Australian Transport Safety Bureau), “Cannabis and Its Effects on Pilot Performance and Flight Safety: A Review” (2004). ↩
M. Asbridge, J.A. Hayden, and J.L. Cartwright, “Acute Cannabis Consumption and Motor Vehicle Collision Risk: Systematic Review of Observational Studies,” BMJ, Vol. 344, No. 14 (2012). ↩
D.S. Hasin, K.M. Keyes, D. Alderson et al., “Cannabis Withdrawal in the United States: Results from NESARC,” Journal of Clinical Psychiatry, Vol. 69, No. 9 (2008). ↩
See Baker et al., “The Therapeutic Potential of Cannabis,” and Foreman, A Nation in Pain. ↩
Patrick Radden Keefe, “Buzzkill,” The New Yorker, November 18, 2013. ↩
Katrina vanden Heuvel, “Why It’s Always Been Time to Legalize Pot,” and other articles in The Nation ’s “Special Issue: Marijuana Wars,” November 18, 2013. ↩
Peter Hecht, Weed Land: Inside America’s Marijuana Epicenter and How Pot Went Legit (University of California Press, May 2014). ↩