Top 10 Myths About Medicinal and Recreational Cannabis

July 25, 2023 - Addressing the top 10 most common myths about medicinal and recreational cannabis is critical to promote informed decision-making, reduce stigma, and foster evidence-based discussions, leading to safer use and better public policies. According to Peter Grinspoon, MD, a primary care physician and a cannabis specialist at Massachusetts General Hospital and an instructor in medicine at Harvard Medical School, there have been numerous myths and misconceptions surrounding cannabis and its health effects for chronic diseases. Here are some of the most common ones.

Myth: Cannabis Has No Medical Benefit.

Reality: While cannabis may have potential therapeutic benefits for certain chronic conditions, it is not a panacea. Its effectiveness varies depending on the disease and individual. Scientific research is still ongoing to determine its full range of medical applications.

Cannabis, also known as marijuana or weed, is a plant that contains over 100 different chemicals called cannabinoids, with tetrahydrocannabinol (THC) and cannabidiol (CBD) being the most well-known. Patients report various benefits of CBD, including relief from insomnia, anxiety, spasticity, and pain. Medical marijuana is commonly used for pain control, especially chronic pain, and as a muscle relaxant. It is also reported to help with glaucoma, weight loss, nausea, post-traumatic stress disorder (PTSD) in veterans, HIV-related pain and wasting syndrome, irritable bowel syndrome (IBS), Crohn's disease, epilepsy, seizures, and multiple sclerosis (MS).

Limited research suggests cannabinoids might have the following benefits:

• Reduce anxiety
• Relieve pain and inflammation
• Control chemotherapy-related nausea
• Inhibit cancer cell growth
• Ease muscle tightness in MS
• Enhance appetite in cancer and AIDS patients

In 2018, Epidiolex, a cannabidiol, received FDA approval for treating seizures linked to Lennox–Gastaut syndrome and Dravet syndrome. The FDA also approved two synthetic cannabinoid medicines, dronabinol (Marinol, Syndros) and nabilone (Cesamet), for chemotherapy-induced nausea and vomiting.

Myth: Smoking Cannabis Is as Harmful as Smoking Tobacco.

Reality: Although smoking any substance can have adverse health effects, research suggests that smoking cannabis is generally less harmful than smoking tobacco. However, it's important to note that smoking cannabis can still negatively affect the respiratory system.

Although a 2008 BMJ study suggested a dose equivalence of 1:2.5–5 between cannabis joints and tobacco cigarettes for adverse effects on lung function, a Pulmonary Therapy article published in 2021 determined that the equivalence of cannabis smoke exposure to cigarette smoke is uncertain.

“Cigarette smoking is responsible for more than 480,000 deaths per year in the United States, including more than 41,000 deaths resulting from secondhand smoke exposure,” according to the CDC. “This is about one in five deaths annually, or 1,300 deaths every day. On average, smokers die 10 years earlier than nonsmokers.”

Myth: People Can Overdose on Cannabis.

Reality: According to the National Institute on Drug Abuse (NIDA), a federal government research institute, there’s never been an adult death attributed to cannabis alone. However, consuming large amounts can lead to discomfort and temporary side effects.

"No one has ever died from a cannabis overdose,” Grinspoon told LifeSciencesIntelligence. “However, from personal experience and the experiences of many people I know, taking too much cannabis can lead to a very unpleasant and uncomfortable experience."

In LaPlace, Louisiana, Christy Montegut, MD, the 70-year-old coroner of St. John the Baptist Parish, ruled that a 39-year-old woman died in February 2019 of excessive amounts of THC — the primary psychoactive component in cannabis. However, experts and researchers are highly skeptical, as no recorded adult deaths have been attributed to THC and the reported THC level in the woman's blood is considered low (8.4 ng/mL).

Reports of deaths related to cannabis use surface occasionally across the country, but evidence for lethal toxicity is lacking. Experts maintain that the likelihood of death solely from THC exposure is incredibly low and insufficient to justify policy changes.

In 2022, a 30-year-old mother in Virginia was arrested after her 4-year-old son died from consuming what she believed to be a CBD gummy — but was found to contain THC. The medical examiner attributed the death to THC toxicity, but cannabis experts are skeptical about the direct link between THC and death. While cannabis itself is highly unlikely to cause death, accidents, or injuries while under its influence can lead to fatalities. Experts believe that children who consume high amounts of THC may become sedated and prone to choking if they vomit.

Myth: Cannabis Use Leads to Lung Cancer.

Reality: The link between cannabis smoking and lung cancer is not as straightforward as tobacco smoking. While heavy, long-term cannabis smoking may be associated with respiratory issues, the evidence for an increased risk of lung cancer is currently inconclusive.

“Smoking cannabis has never — despite infinite studies from the government trying to establish a link — been associated with chronic obstructive pulmonary disease (COPD), emphysema, or lung cancer,” said Grinspoon. “At the same time, smoking cannabis does cause acute bronchitis in the lungs, and physicians don't recommend smoking it due to the combustion products, such as tar, benzene, and polycyclic, aromatic hydrocarbons.”

The 2021 Pulmonary Therapy article determined that inhaling cannabis through combustion leads to significant respiratory effects, including changes in lung function and symptoms. However, the relationship between lung cancer and inhaling cannabis through combustion remains unclear.

Myth: Cannabis Is Extremely Addictive.

Reality: While cannabis can be habit-forming for some individuals, not everyone who uses it becomes addicted. The risk of addiction depends on various factors, including genetics, frequency of use, and personal susceptibility.

“The rates of cannabis addiction or cannabis use disorder have been significantly and irresponsibly inflated by psychiatrists during the war on drugs,” said Grinspoon. “They claim that between 9% and 33% of adults using cannabis get addicted to it, but it's more likely around 2–5%.”

The study published in the American Journal of Psychiatry found that the prevalence of 12-month and lifetime marijuana use disorder was 2.5% and 6.3%, respectively. Those with the condition had frequent marijuana use, with an average of 225.3 and 274.2 days used per year for 12-month and lifetime disorder cases, respectively.

The odds of the disorder were higher among men, Native Americans, unmarried individuals, those with low incomes, and young adults. Marijuana use disorder was associated with other substance, affective, anxiety, and personality disorders. Disability was linked to 12-month marijuana use disorder. As the severity of the condition increased, the associations became stronger. Only 24.3% of individuals with lifetime marijuana use disorder sought 12-step programs or professional treatment.

“Yes, people can get addicted to cannabis but don't tend to injure themselves or break into pharmacies with cannabis addiction like opiate addictions,” said Grinspoon. “Cannabis has low-to-moderate abuse liability. It's certainly not nearly as high as alcohol or tobacco, which are completely de-scheduled. People don't tend to die from cannabis addiction.”

Myth: Cannabis Use Causes Long-Term Memory Loss.

Reality: Numerous studies have debunked the myth that cannabis use causes long-term memory loss. Research shows that while cannabis may impact short-term memory, mainly due to THC, there is little to no evidence supporting the notion that it leads to permanent or significant long-term memory impairment.

Long-term cannabis use during adolescence has been associated with changes in the hippocampus and potential effects on memory processes. However, the impact on memory is not as severe as some claims suggest, and it does not result in permanent memory loss.

For adults, the evidence suggests that cannabis primarily affects short-term memory, and any potential impact on long-term memory is minimal and not significant enough to cause long-term memory loss.

The idea that cannabis use inherently causes long-term memory loss is unfounded, and the available research supports a more nuanced understanding of its effects on memory functions.

Grinspoon supports the idea that cannabis is a safer option than certain pharmaceutical drugs like Ambien, which are known to cause memory loss and dissociative events. Grinspoon believes using a small amount of CBD with THC in edibles or tinctures for sleep is a low-risk choice. However, doctors' limited knowledge and involvement hinder the potential harm reduction that cannabis could offer if utilized more widely.

Myth: Cannabis Is a Gateway Drug.

Reality: The idea that using cannabis inevitably leads to the use of harder drugs has been debunked. While there may be an association between early cannabis use and subsequent drug use, correlation does not imply causation. Multiple factors, such as individual vulnerabilities and social influences, contribute to drug use patterns.

According to a 2023 Psychological Medicine study, researchers analyzed over 4,000 twins from Colorado and Minnesota. They found no association between cannabis legalization and rises in cognitive, psychological, social, relationship, or financial issues. Despite concerns that cannabis could be a gateway drug to other more harmful substances, the study found no changes in illicit drug use after legalization.

Based on this specific study's findings, there is no evidence to support the notion that cannabis acts as a gateway drug among adults in states where it has been legalized for recreational use.

Myth: All Forms of Cannabis Have the Same Effect.

Reality: Different strains and forms of cannabis contain varying combinations of cannabinoids and other compounds, which can lead to different health effects. For instance, CBD (cannabidiol) is non-intoxicating and may have therapeutic potential, while THC (delta-9-tetrahydrocannabinol) is responsible for the psychoactive effects of cannabis.

No, all forms of cannabis do not have the same effect. Cannabis is a plant that contains various chemical compounds, with two primary classes of compounds that have significant effects: cannabinoids and terpenes.

Cannabinoids

The most well-known cannabinoids are tetrahydrocannabinol (THC) and cannabidiol (CBD), but there are over 100 others identified in cannabis. THC is the psychoactive compound responsible for the "high" associated with marijuana use, and it can cause euphoria, altered perception, relaxation, and increased appetite. Conversely, CBD is non-psychoactive and is more commonly associated with potential therapeutic effects like pain relief, reduced anxiety, and anti-inflammatory properties.

Different strains and forms of cannabis can have varying ratios of THC to CBD, leading to diverse effects on users. Some strains may be high in THC and low in CBD, resulting in a more intense psychoactive experience, while others may have balanced ratios or high CBD content for a milder, non-intoxicating effect.

Terpenes

Terpenes are aromatic compounds found in cannabis and other plants. They contribute to the distinctive smell and taste of different strains and play a role in influencing the overall effects of cannabis. Some terpenes may promote relaxation, while others might increase alertness or alter how cannabinoids interact with the body.

“Terpenes are the thing that gives cannabis flavor and smell: some make you awake or sleepy,” said Grinspoon.

The combination of cannabinoids and terpenes in a particular strain creates what is known as the "entourage effect." This refers to the idea that the various compounds in cannabis work together synergistically, enhancing and modulating each other's effects.

The effects of cannabis can also be influenced by factors such as the method of consumption (smoking, vaping, edibles, etc.), dosage, individual tolerance, and the user's overall state of mind and environment.

It's essential to be aware that the effects of cannabis can vary widely among individuals, and what might be experienced by one person may differ significantly for another. Additionally, the legality and regulations surrounding cannabis can vary from region to region, so it's important to be informed about local laws and make responsible choices regarding its use.

Myth: Cannabis Use Causes Psychosis.

Reality: While cannabis can exacerbate existing psychotic disorders in susceptible individuals, it does not necessarily cause psychosis on its own.

Studies indicate that cannabis use is linked to a higher risk of earlier onset of psychotic disorders, particularly in individuals with additional risk factors like a family history of such conditions. Cannabis intoxication, especially at high doses, can induce temporary psychotic episodes. Experiencing these episodes might be associated with an increased risk of later developing a psychotic disorder. The interplay of a person's genetics may also influence this relationship.

Evidence suggests that cannabis use can lead to earlier onset of psychosis in people with genetic risk factors for psychotic disorders. It may also worsen symptoms in those already affected. Additionally, some evidence links cannabis use to other mental illnesses and self-harm, including suicidal thoughts and behaviors. However, more research is needed to fully understand these relationships, as many factors, like frequency of use, potency, and individual characteristics, influence the impact of cannabis on mental health. Prospective, longitudinal research is necessary to determine causation and vulnerability factors.

According to Grinspoon, once individuals transition into emerging adulthood, addressing specific questions becomes a matter of education rather than outright prohibition. One such question pertains to cannabis use, where particular groups must exercise caution. People with a personal or family history of psychosis are among those who should avoid using cannabis. The connection between cannabis and psychosis is complex, and claims by some psychiatrists suggesting that cannabis raises the rate of schizophrenia are unsubstantiated. “Despite a significant increase in cannabis users worldwide, the prevalence of schizophrenia has remained stable at around 1% since the 1950s, indicating that cannabis is unlikely to be a direct cause.”

However, while cannabis itself may not cause an increase in the overall occurrence of schizophrenia, it can potentially trigger the onset of schizophrenia earlier in individuals already predisposed to the condition. Although the absolute number of schizophrenia cases may not rise, this early manifestation can have profound consequences. For instance, if psychosis occurs at age 20 instead of 25, young adults lose five crucial years to learn adult skills, self-care, and functioning in society. Early development of psychosis can lead to worse outcomes compared to later onset.

Therefore, it is essential to recognize that cannabis can be harmful in specific situations, particularly in triggering psychosis or destabilizing individuals with bipolar disorder. While some individuals with bipolar disorder claim that cannabis helps them, others may experience significant destabilization. As a result, a nuanced understanding of cannabis use and its potential impacts on mental health is crucial to make informed decisions regarding its consumption, Grinspoon said.

Myth: Smoking Cannabis Is the Only Method to Consume It.

Reality: While cannabis can be smoked, cannabis specialists recommend oral consumption over smoking due to its gentler effect, controlled dosing, and avoidance of respiratory issues. However, the choice of consumption method should be based on individual preferences and health considerations. Responsible and informed cannabis use is essential for a safe experience.

While the availability of methods may vary depending on the legal regulations in each state, there are at least 12 standard methods for consuming cannabis.

These methods include the following:

• Smoking (joints or pipes)
• Vaping (heating plant material or concentrates)
• Edibles (food products like brownies, gummies, and candy)
• Tinctures (sublingual extracts)
• Topicals (creams, lotions, and balms)
• Dabbing (inhaling concentrated extracts)
• Beverages (teas and sodas)
• Capsules (pill or capsule form)
• Suppositories (rectal or vaginal insertion)
• Sublingual Strips (dissolving strips under the tongue)
• Patches (adhesive patches on the skin)
• Sprays (oral sprays for quick consumption)

"For individuals who require immediate relief, there is an alternative option known as a dry herb vaporizer. This is particularly beneficial for those undergoing chemotherapy who cannot afford to wait an hour for an edible to take effect when they experience nausea. The dry herb vaporizers function by heating the herb to around 400 degrees, producing a vapor that allows the extraction of cannabinoids without the harmful effects of smoking or combustion products. Ultimately, using a dry herb vaporizer is much gentler on the lungs and overall health.”

It is essential to consult with healthcare professionals and rely on scientific research to obtain accurate and up-to-date information about the potential benefits and risks of cannabis for specific chronic diseases.

Grinspoon advises patients to discuss medical marijuana with their doctors openly and urges doctors to be educated, open-minded, and non-judgmental about patients' use of medical marijuana to maintain trust in the doctor–patient relationship.