Marijuana and related substance misuse are complex issues impacting family medicine, patient health, and public health. The American Academy of Family Physicians (AAFP) believes family physicians are essential in addressing all forms of inappropriate substance use. The AAFP urges its members to be involved in the diagnosis, treatment, and prevention of substance use, as well as secondary diseases impacted or caused by use. The World Health Organization (WHO) reports approximately 2.5% of the global population uses cannabis annually, making it the most commonly used drug worldwide.1 Simultaneously, the AAFP acknowledges preliminary evidence indicates marijuana and cannabinoids may have potential therapeutic benefits, while also recognizing subsequent negative public health and health outcomes associated with cannabis use.2
During the 20th century, law enforcement and public policy activities have undermined opportunities for scientific exploration. Barriers to facilitating both clinical and public health research regarding marijuana is detrimental to treating patients and the health of the public. The lack of regulation poses a danger to public health and impedes meaningful, patient-centered research to exploring both therapeutic and negative impacts of marijuana and cannabinoids.
Marijuana Possession for Personal Use
The American Academy of Family Physicians (AAFP) opposes the recreational use of marijuana. However, the AAFP supports decriminalization of possession of marijuana for personal use. The AAFP recognizes the benefits of intervention and treatment for the recreational use of marijuana, in lieu of incarceration, for all individuals, including youth.3
The AAFP also recognizes that several states have passed laws approving limited recreational use and/or possession of marijuana. Therefore, the AAFP advocates for further research into the overall safety and health effects of recreational use, as well as the effects of those laws on patient and societal health.4
It should be noted that cannabis and marijuana are not interchangeable terms. In this position paper, cannabis is an overarching term used to refer to the plant Cannabis sativa. Substances derived from the cannabis plant include marijuana, hemp, and cannabinoids.
Call to Action
Family physicians have a vested interest in policies that advance and protect the health of their patients and the public. The regulatory environment surrounding cannabis, medical and recreational marijuana, and cannabidiol (CBD) is rapidly changing, along with the retail environment. This shift has not been accompanied by robust scientific research regarding the health effects of cannabis, both therapeutic or detrimental. The AAFP recognizes the need for substantial clinical, public health, and policy evidence and research regarding cannabis, marijuana, cannabinoids, and CBD to inform evidence-based practice and the impact on public health.
In the Exam Room
Cannabis use, both medically and recreationally, is prevalent throughout history. Extensive evidence indicates cannabis was used by ancient civilizations, dating back more than 5,000 years ago.1 In the U.S. in the 19th and early 20th centuries, cannabis was frequently used for medicinal purposes, often prescribed by clinicians.1,5 Cannabis was first listed in the United States Pharmacopoeia in 1851, indicating use as an analgesic, hypnotic, and anticonvulsant agent.5 After the 1937 Marihuana Tax Act, in 1942, cannabis was removed from the United States Pharmacopoeia.5
Attitudes and perceived risk of marijuana use have changed with the varying levels of legalization in the U.S. Surveying marijuana use is essential to gauge public health implications of increased access to marijuana, cannabinoid, and cannabis products. According to the 2018 National Institute on Drug Abuse (NIDA) Monitoring the Future Survey (MTF), daily, past month, past year, and lifetime marijuana use among 8th graders has declined, and remained unchanged in 10th and 12th graders, when compared to the 2013 MTF survey.6 Despite the changing landscape of marijuana regulations nationwide, past year use of marijuana reached and maintained its lowest levels in more than two decades in 2016 among 8th and 10th graders.6 However, marijuana vaping did significantly increase between 2017 and 2018, mirroring trends in youth tobacco use.6 The NIDA 2017 National Survey on Drug Use and Health indicates nearly 53% of adults between the ages of 18-25 have tried marijuana at some point in their lifetime, 35% have used marijuana within the past year, and 22% within the past month.7 While the lifetime use remains relatively stable for this cohort, from 2015-2017, past year and past month use increased 2.7% and 2.3%, respectively.7 Nearly half of adults 26 or older reported using marijuana at some point in their lifetime.7 Although adults ages 26 and up report the highest percentage of lifetime use, this age group has a significantly lower past year use (12%) and past month use (8%).7
Forms and Use of Cannabis
The cannabis plant, Cannabis sativa, is comprised of both non-psychoactive and psychoactive chemicals called cannabinoids.5 The cannabinoid commonly known for its psychoactive properties is delta-9-tetrahydrocannabinol (THC).5 CBD is the most abundant cannabinoid in cannabis, and is considered to be largely non-psychoactive.5 The biological system responsible for the synthesis and degradation of cannabinoids in mammals is referred to as the endocannabinoid system, which is largely comprised of two g-coupled protein receptors (GPCRs).8 The GPCRs—CB1 and CB2—are found throughout many bodily tissues. However, CB1 is most concentrated in the neural tissues.5,8 CB2 receptors are found in the brain, but are mostly found in immune cells, like macrophages, microglia, osteoclasts, and osteoblasts.5,8
There are many forms of, and products derived from, the Cannabis sativa plant, including hemp, CBD, and marijuana. Cannabis sativa with less than 0.3% THC is considered industrial hemp, and can be used for industrial agriculture cultivation.9,10 Industrial hemp can be harvested and used for many things, including fibers for textiles, food products, and building materials.11,12 CBD, the non-psychoactive cannabinoid, is extracted from the flower of industrial hemp.13 Marijuana and hemp, technically speaking, are the same plant.13 However, the hemp variety of cannabis contains no more than 0.3% THC, while the marijuana variety contains 5-20% THC.13
Marijuana and CBD are most commonly used via inhalation, ingestion, and topical absorption.5 Inhalation can be through combustible mechanisms using dried flowers, including the use of a pipe, rolled joints, blunts, and water pipes (also called bongs).14 Vaping marijuana and CBD concentrates are an increasingly popular inhalation method.5,6 Concentrates, the concentrated form of marijuana and CBD, come in various forms, including oil, butter, or a dark sticky substance often referred to as shatter.15 Concentrates can be both smoked or vaporized, and may also be used as additives or cooking agents for ingestion.5,15 There are many different ways to ingest cannabinoids. Food products—called edibles—like brownies, gummies, cookies, and candies are common forms of cannabis ingestion, as well as liquid forms like juices, soda, and tea.5,16 Tinctures are liquid, ultra-concentrated alcohol-based cannabis extracts commonly applied in and absorbed through the mouth.17 Topical cannabis is applied to, and absorbed through, the skin in a cream or salve form.18
Routes or methods of administration affect cannabis delivery. When cannabis is smoked or vaporized, onset of effect is within 5-10 minutes with a duration of 2-4 hours.19 When ingested, effect is within 60-180 minutes with a duration of 6-8 hours.19 The oromucosal route has an onset of 15-45 minutes and a duration of 6-8 hours.19 Topical administration of cannabis or cannabinoids has variable onset and duration.19 The smoked or vaporized method offers the more rapid activity for acute symptoms with the topical preparations offering less systemic effects.19
Although there is preliminary evidence indicating cannabinoids may have some therapeutic benefit, a large portion of the evidence is very limited for many reasons. These include small sample sizes, lack of control groups, poor study design, and the use of unregulated cannabis products. There are also clear negative health and public health consequences that must be considered, as well as the need for a significant increase in evidence. More research is needed to create a robust evidence base to weigh the potential therapeutic benefits against potential negative impacts on health and public health. Currently, there are three medical formulations of cannabis approved for use in the U.S.; dronabinol, nabilone, and epidiolex.20 Nabiximols is approved for use in the United Kingdom.21 Dronabinol is delta-9 THC and ingested as either an oral solution or an oral capsule.22 Nabilone is an oral capsule containing synthetic THC.23 Epidiolex is a CBD oral solution.24 Nabiximols is an oral mucosa spray containing the cannabinoids THC and CBD.25
In 2015, Whiting, et al, performed a meta-analysis and systematic review of research on the medical use of cannabis.25 This systematic review served as the basis for many recommendations in 2017 by the National Academy of Science, Engineering, and Health Report on medical marijuana.5 Dronabinol, nabilone, and nabiximols were included in the studies. However, other cannabis formulations were found in research trials, including CBD, marijuana, and other cannabinoids.26 Evidence is most substantial for nausea and vomiting associated with chemotherapy, chronic pain treatment, multiple sclerosis spasticity, and intractable seizures associated with Dravet syndrome and Lennox-Gastaut syndrome.27 There is moderate evidence for the use of cannabinoids for sleep and limited evidence for use in psychiatric conditions, such as post-traumatic stress disorder, depression, anxiety, and psychosis; appetite stimulation and weight gain; and no evidence for cancer treatment.5
Dronabinol and nabilone were both approved in 1985 for use in treating refractory chemotherapy-induced nausea and vomiting.5,23 Dronabinol is approved by the Food and Drug Administration (FDA) for appetite stimulation and weight gain, despite limited and often inconclusive evidence that it or other cannabinoids are effective.22 This drug has traditionally been used in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients to mitigate weight loss and to treat anorexia-cachexia syndrome associated with cancer and anorexia nervosa.5,22
Cannabinoids have been assessed for chronic pain management. Many forms of chronic pain management were studied, including cancer and chemotherapy-induced pain, fibromyalgia, neuropathic pain, rheumatoid arthritis, non-cancer pain, and musculoskeletal pain. Several studies indicate smoked THC and nabiximols were both associated with pain reduction.5,25,26 There is limited, mixed evidence regarding the viability of cannabinoids for some forms of chronic pain management.5 However, limitations exist with these studies, including the variable doses of THC and CBD; unregulated, non-FDA approved products; and conflicting evidence. Studies assessing cannabinoids in treating the spasticity due to multiple sclerosis or paraplegia have mixed results. The cannabinoids nabiximols, dronabinol, and TCH/CBD have all been associated with decreased spasticity. Nabilone and nabiximols were the only drugs with statically-significant decreases.2,25
In 2018, the FDA approved a cannabidiol oral solution called epidiolex for the treatment of refractory seizures associated with Dravet syndrome and Lennox-Gastaut syndrome.28 Epidiolex was associated with significant seizure reduction when compared to placebo.29–31 Dravet syndrome and Lennox-Gastaut syndrome are disorders associated with severe seizures, impaired cognitive skills and development, and uncontrollable muscle contractions.29–31
Moderate evidence exists for the use of cannabis for sleep. Nabilone and nabiximols have been associated with improvement in sleep from a baseline and sleep restfulness.2,5,25 Improved sleep was also considered a secondary outcome when evaluating other conditions (chronic pain, multiple sclerosis) with various cannabinoids.2,5,25
There is limited evidence for the use of cannabis or cannabinoids for the treatment of post-traumatic stress disorder (PTSD), anxiety, depression, or psychosis. Of the limited evidence, nabilone was associated with a decrease in PTSD related nightmares.5,25 One small study indicated CBD improved public speaking anxiety.5 There are no studies directly evaluating the effectiveness of cannabis in the treatment of depression. However, some studies measured depression as a secondary outcome, but indicated no difference in depression when compared to placebo.25 Limited evidence (two studies) have shown no difference in treating psychosis with CBD, amisulpride, or placebo.25 Evidence indicates individuals who use marijuana are more likely to experience temporary psychosis and chronic mental illness, including schizophrenia.5,32
There was no evidence or insufficient evidence for the use of cannabis or cannabinoids in the treatment of cancer; neurodegenerative disorders like Huntington’s chorea, Parkinson’s disease, or amyotrophic lateral sclerosis; irritable bowel syndrome; or addiction.5
Cannabis overdose is rare in adults and adolescents.33 Children who experience acute intoxication from cannabis generally ingest marijuana or other cannabinoids through experimentation.33 When compared to adults and adolescents, children are more likely to experience life-threatening symptoms of acute cannabis intoxication, which may include depressed respiration rates, hyperkinesis, or coma.33 Management consists of supportive care dependent on the manifestation of symptoms.33 Adults and adolescents may experience increased blood pressure and respiratory rates, red eyes, dry mouth, increased appetite, and slurred speech.33
Negative health effects are also associated with marijuana and cannabinoid use. Frequent marijuana use has been associated with disorientation. In teens, it has been linked with depression, anxiety, and suicide.5,32 However, this is not a proven causal relationship. Lung health can also be negatively impacted depending on the delivery mechanism.34 Smoking marijuana can cause lung tissue scarring and damage blood vessels, further leading to an increased risk of bronchitis, cough, and phlegm production.34 This generally decreases when users quit.34
Secondhand smoke is a serious issue associated with marijuana use. However, there is limited evidence on how it impacts heart and lung health.34 Detectable THC has been found in children who live in the home or have a caretaker who use marijuana, subjecting children to developmental risks of THC exposure.35 Fetal, youth, and adolescent exposure to THC is associated with negative health effects, including impacting brain development.34 There is inconsistent, insufficient evidence to determine the long-term effects of marijuana and cannabinoid use while breastfeeding.36 However, THC has been detected in breast milk for up to six days post-cannabinoid use, and exposure to cannabinoids is known to impact development in children.37 Evidence also suggests cannabis use during pregnancy may be linked with preterm birth.38 Cardiovascular health may be impacted by smoked marijuana use. However, the negative health effects are associated with the harmful chemicals in smoke similar to tobacco smoke.34
Approximately 9% of all individuals who use marijuana develop an addiction, which is variable by age of first use and frequency of use.34 That number for addiction jumps to 17% for individuals who begin using marijuana as teenagers and 25-50% of those who smoke marijuana daily.34 Marijuana use does not typically lead to harder drug use, like cocaine and heroin, in most individuals.39 Further research is needed to evaluate any potential gateway effect.39
Mental health outcomes associated with marijuana use include an increased risk of anxiety and depression. Marijuana has been linked to schizophrenia, psychoses, and advancing the trajectory of the disease, particularly in individuals with pre-existing genetic indicators.5,34 Global research also suggests daily use of high-potency marijuana increases risk for psychotic episodes among individuals with no underlying mental health condition.40 While it is widely accepted that marijuana acutely impairs cognitive function, studies suggest differential outcomes regarding short- versus long-term cognitive impairment.34
The regulatory environment surrounding cannabis, marijuana, and cannabinoid research creates barriers detrimental to facilitating meaningful medical, public health, policy, and public safety research. Approval for research expands beyond institutional review boards. Due to the Schedule I classification by the Drug Enforcement Agency (DEA), researchers seeking to investigate health effects associated with cannabis must follow a regimented application process.41 Applicants must submit an Investigational New Drug (IND) application to the FDA, which will then be reviewed to determine scientific validity and research subjects’ rights and safety.42 Researchers must also follow the NIDA regulatory procedures for obtaining cannabis for research purposes.41 Researchers may only use cannabis supplied by the University of Mississippi, the single NIDA-approved source for cannabis research.41 Requiring research to rely on one source of cannabis limits availability and the variety of products. While the University of Mississippi cultivates different strains of cannabis, it is unable to supply the vast array of strains of cannabis found in the evolving retail environment with varying levels of THC, CBD, and cannabinoid content.5 Substantial funding and capacity is required for researchers to obtain all regulatory approval and remain in compliance while conducting cannabis-related research. The required processes and procedures present a serious burden, dissuading researchers from pursuing cannabis-related projects. This has led to a lack of empirical evidence regarding a myriad of health-related issues, including potential therapeutic benefits of cannabis, public health impact, health economics, and the short- and long-term health effects from cannabis use.
In order to address the research gaps associated with both beneficial and harmful effects of cannabinoids used in both medical and recreational capacities, the AAFP calls for a comprehensive review of processes and procedures required to obtain approval for cannabis research.
The AAFP encourages the appropriate regulatory bodies, such as the DEA, NIDA, FDA, Department of Health and Human Services (DHHS), National Institutes of Health (NIH), and the Centers for Disease Control and Prevention (CDC), to collaborate with non-governmental stakeholders to determine procedures to decrease the burden of cannabis-related research while maintaining appropriate regulatory safety guards. This should include a reclassification of marijuana from Schedule I to facilitate clinical research. The AAFP calls for increased funding from both public and private sectors to support rigorous scientific research to address gaps in evidence regarding cannabis to protect the health of the public and inform evidence-based practices.3 Future research should address the impact of cannabis use on vulnerable and at-risk populations.
While cannabis was federally regulated in 1906 for consumer and safety standards and labeling requirements, the Marihuana Tax Act of 1937 was the first federal regulation to impose a fine or imprisonment for non-medical use and distribution of cannabis.5 The tax act also regulated production, distribution, and use of cannabis, further requiring anyone dealing with cannabis to register with the federal government.5 In 1970, the DEA classified marijuana as a Schedule I drug, which is defined as a drug with no current acceptable medical use and a high potential for abuse.43 Other Schedule 1 drugs include heroin, lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote.43 Since this class of substances is determined as having no medical usage, they cannot be legally prescribed and thus, there is no medical coverage for them.
Marijuana is illegal under federal law. Penalties cover possession, sale, cultivation, and paraphernalia. However, the Agriculture Improvement Act of 2018 included a U.S. Department of Agriculture (USDA) Hemp Production Program, removing hemp from the Controlled Substances Act.10,44 As a result, CBD sourced from hemp plants containing no more than 0.3% THC is legal to produce.10,44 The FDA has approved three medications containing cannabinoids: epidiolex (CBD), dronabinol, and nabilone (synthetic cannabinoids).5 No other forms of cannabis are currently regulated by the FDA. The AAFP calls upon the FDA to take swift action to regulate CBD and cannabinoid products now legal in order to protect the health of the public.
States have separate marijuana, cannabinoid, and cannabis laws, some of which mirror federal laws, while others may be more harsh, or have decriminalized and even legalized marijuana and cannabis.45 In 1996, California was the first state to legalize the medical use of marijuana.46 States have subsequently decriminalized and/or legalized cannabinoids, medical marijuana, and recreational marijuana.46 As of August 2019, 30 states, along with the District of Columbia, Guam, and Puerto Rico have legalized marijuana in varying forms.46 Decriminalization laws may include reduction of fines for possession of small amounts of marijuana, reclassification of criminal to civil infractions, excluding the infraction from criminal records and expunging prior offenses and convictions related to marijuana.47 Thirty-three states, along with the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands have a comprehensive, publicly-available medical marijuana/cannabis program, and 13 of these states have also removed jail time for possessing small amounts of non-medical marijuana.47 Adult recreational marijuana use is legal in 13 states and the District of Columbia.47 Vermont and the District of Columbia, however, do not allow the sale of marijuana for recreational purposes. This means it is not a crime to use and possess marijuana recreationally, but commercial sales are not allowed.47 States have also authorized the sale of products that have low levels of THC, but high levels of CBD. These products are widely available in retail locations, but are highly unregulated.47 The benefits of CBD touted by the public and retailers are largely anecdotal. The vast majority of these claims are not substantiated by valid research.
Decriminalizing and legalizing marijuana can decrease the number of individuals arrested and subsequently prosecuted for possession and/or use.48 However, evidence suggests that these practices are not applied equitably. People of color are more likely to be arrested and prosecuted for marijuana possession despite overall decreased arrest rates.48 Incarceration impacts health. People who are incarcerated have significantly higher rates of disease than those who are not, and are less likely to have access to adequate medical care.49
The AAFP “opposes the recreational use of marijuana. However, the AAFP supports decriminalization of possession of marijuana for personal use. The AAFP recognizes the benefits of intervention and treatment for the recreational use of marijuana, in lieu of incarceration, for all individuals, including youth.”4 The AAFP calls for family physicians to advocate to prevent unnecessary incarceration by diverting eligible people from the justice system to substance abuse and/or mental health treatment.49
There are many public health considerations when regulating cannabis products. Serious public health concerns include impaired driving, youth exposure to advertisements, and accidental poisoning in children. Second to alcohol, marijuana is the most common illicit drug associated with impaired driving and accidents.34 Marijuana slows reaction time and decision making, substantially increasing risk for traffic accidents.50 Some states have a zero-tolerance policy, where there is no allowable detectable level of THC while driving, while other states have set five nanograms per milliliter or higher limits of THC, or minimally-detectable amounts of THC.51
Evidence indicates adolescents who are exposed to medical marijuana advertising are more likely to have positive views of and subsequently use marijuana.52 Those exposed to medical marijuana advertising were more likely to report past use and expectant future use.52 These adolescents also reported agreeing with statements like, marijuana helps people relax and get away from their problems.52 Adolescent exposure to medical marijuana advertising was also associated with self-reporting negative consequences associated with marijuana use, including missing school and concentration issues.52 The AAFP calls for immediate regulation of advertising of all marijuana and cannabinoid products to decrease youth exposure to aid in preventing initiation and subsequent use of marijuana.
Children are most susceptible to severe effects associated with marijuana poisoning, including decreased coordination, lethargy, sedation, difficulty concentrating, and slurred speech.53 Exposure may also include serious, potentially life-threatening symptoms like respiratory distress and coma.33 Unintentional exposures to marijuana in children have increased each year since 2012, likely due to legalization policies across the U.S. and popularity of edibles.53 Edibles often look exactly like their non-THC counterparts, and come in brightly colored packaging appealing to children, often mimicking candy products.53 Effective legislation requiring childproof packaging for edible products can help mitigate and prevent unintentional exposure in children.54 Family physicians should discuss safe storage of all cannabis products with their patients who live with children.54 Under the Child Abuse Prevention and Treatment Act (CAPTA), physicians are mandated reporters of suspected child abuse and neglect.55 The 2010 law requires states to enact laws for reporting substance use-exposed infants to child protective services.55
Family physicians play a key role in addressing marijuana, cannabinoid, and cannabis product use; reducing barriers to research; and advocating for appropriate policy to protect the health of patients and the public.
Family physicians can address the inappropriate use of marijuana, cannabinoid, and cannabis products. Family physicians should discuss safe storage of all cannabis products with patients who live with or serve as primary caregivers for children to prevent unintended exposure.56 It is important to discuss the developmental and negative impacts of marijuana and cannabis products with individuals who are or can become pregnant, children, and adolescents. Family physicians should also emphasize the serious consequences of impaired driving and marijuana intoxication.
It is essential to decrease barriers to research all forms of marijuana, cannabis, and cannabinoids, including a reclassification of cannabis as a Schedule I drug. High-quality research regarding the impact on patients, public health, society, and health policy are essential to providing patient-centered care and promoting evidence-based public health practices. Immediate regulations for marijuana and cannabinoid products, including CBD, like product safety and consistency safeguards, child-proof packaging, labeling, marketing claims and advertising, and impairment standards are vital for consumer safety and injury prevention. Regulatory measures focused on preventing youth initiation of marijuana and cannabinoid product use must be prioritized to prevent a public health epidemic.
The health benefits associated with intervention and treatment of recreational marijuana and cannabinoid use, in lieu of incarceration, is an important policy consideration.
Utilizing an interdisciplinary, evidence-based approach to addressing both medical and recreational marijuana and cannabis use is essential to promote public health, inform policy, and provide patient-centered care. Family physicians, in partnership with public health and policy professionals, can play an imperative role in addressing the changing landscape of marijuana and cannabis products.
(July 2019 BOD)