What Impact Do You Believe the Increasing Legalization of Marijuana Will Have Upon Mental Illness?
So far, medical marijuana has been legalized in 31 states and nine have legalized its recreational use. The Marijuana Policy Project estimates that more than 2.8 million people in the United States are using marijuana, or cannabis, as medicine. Recreational use is even higher, with more than 22.2 million users, according to a 2015 national survey.
Some research suggests that marijuana use is likely to precede use of other licit and illicit substances and the development of addiction to other substances. For instance, a study using longitudinal data from the National Epidemiological Study of Alcohol Use and Related Disorders found that adults who reported marijuana use during the first wave of the survey were more likely than adults who did not use marijuana to develop an alcohol use disorder within 3 years; people who used marijuana and already had an alcohol use disorder at the outset were at greater risk of their alcohol use disorder worsening. Marijuana use is also linked to other substance use disorders including nicotine addiction. Early exposure to cannabinoids in adolescent rodents decreases the reactivity of brain dopamine reward centers later in adulthood. To the extent that these findings generalize to humans, this could help explain the increased vulnerability for addiction to other substances of misuse later in life that most epidemiological studies have reported for people who begin marijuana use early in life. It is also consistent with animal experiments showing THC’s ability to "prime" the brain for enhanced responses to other drugs.49 For example, rats previously administered THC show heightened behavioral response not only when further exposed to THC but also when exposed to other drugs such as morphine—a phenomenon called cross-sensitization. These findings are consistent with the idea of marijuana as a "gateway drug." However, the majority of people who use marijuana do not go on to use other, "harder" substances. Also, cross-sensitization is not unique to marijuana. Alcohol and nicotine also prime the brain for a heightened response to other drugs and are, like marijuana, also typically used before a person progresses to other, more harmful substances. It is important to note that other factors besides biological mechanisms, such as a person’s social environment, are also critical in a person’s risk fo drug use. An alternative to the gateway-drug hypothesis is that people who are more vulnerable to drug-taking are simply more likely to start with readily available substances such as marijuana, tobacco, or alcohol, and their subsequent social interactions with others who use drugs increases their chances of trying other drugs. Further research is needed to explore this question.
Differences in how state and local governments regulate the commercial market will generate heterogeneous effects on the retail price of marijuana, which will have important consequences for both the extensive and intensive margins of use and abuse (Pacula & Lundberg 2014, Pacula et al. 2014b). Moreover, because marijuana is involved in a variety of forms and potencies, choices about the tax level, base, and point of collection can also influence the products and potencies available to consumers and the prices they face (Caulkins et al. 2015). Currently, retail stores are allowed to offer marijuana flowers, concentrates, and infused products in solid and liquid form. The original legalization measures in Colorado and Washington did not explicitly distinguish between product types when establishing consumer purchase limits. As marijuana concentrates and infused products have captured an increasing share of legal retail sales, regulations have had to expand. Effective October 2016, adult residents in Colorado are limited to purchasing 1 ounce of marijuana flower, 8 g of concentrates, or 80 10-mg servings of THC in infused product form. In Washington and Alaska, consumers can purchase 1 ounce of marijuana flower, 7 g of marijuana concentrates, 16 ounces of infused product in solid form, or 72 ounces in beverage form. Oregon’s regulations are similar, except for a stricter limit of 5 g for marijuana concentrates. Alaska’s rules also limit buyers to 5,600 mg of THC in a single purchase. Because legal markets will continue to evolve before these questions are fully answered, the real work that lies ahead relies on obtaining more accurate information on the amount and type of products that various people are consuming. Imagine trying to communicate to the public health field the health benefits or harms of alcohol consumption without being able to indicate specific levels or amounts that translate into impairment in well-understood dose-response relationships. Or imagine trying to assess the harmful effects of smoking without being able to differentiate an experimental or occasional smoker from someone who smokes a pack a day. Yet, that is exactly where the science is today in terms of our measurement of marijuana consumption.
Given these points, we need equally unambiguous and well-funded advertising campaigns on the risks of cannabis. Instead, we are now in the worst of all worlds. Marijuana is legal in some states, illegal in others, dangerously potent, and sold without warnings everywhere. But before we can do anything, we—especially cannabis advocates and those in the elite media who have for too long credulously accepted their claims—need to come to terms with the truth about the science on marijuana. That adjustment may be painful. But the alternative is far worse, as the patients at Mid-Hudson Forensic Psychiatric Institute—and their victims—know.
Sevigny EL, Pacula RL, Heaton P. 2014. The effects of medical marijuana laws on potency. Int. J. Drug Policy 25:308–19
Pacula RL, Kilmer B, Wagenaar AC, Chaloupka FJ, Caulkins JP. 2014bDeveloping public health regulations for marijuana: lessons from alcohol and tobacco. Am. J. Public Health 104(6):1021–28
Sobesky M, Gorgens K. 2016. Cannabis and adolescents: exploring the substance misuse treatment provider experience in a climate of legalization. Int. J. Drug Policy 33:66–74
Stringer RJ, Maggard SR. 2016. Reefer madness to marijuana legalization: media exposure and American attitudes toward marijuana (1975–2012).