It’s also important to know that the potency of today’s cannabis is very different from the product your grandparents may have used in the 1960s or ’70s. For example, modern marijuana products register an average of 15-20% tetrahydrocannabinol (THC, the psychoactive component of cannabis), with some products advertising 90% THC. In contrast, the average THC content of marijuana smoked at Woodstock back in 1969 had less than 1% THC.
The Yale School of Medicine recently announced that the Yale Center for the Science of Cannabis and Cannabinoids will investigate acute and chronic effects of cannabis and cannabinoids on human neurodevelopment and mental health. International expert Deepak Cyril D’Souza leads this organization. He noted, “Beyond the plant [are] a staggering array of other cannabis products with an even higher THC content, like dabs, oils, and edibles—some as high as 90%.”
Synthetic cannabinoids (SCs) are even more fraught with consequences. They target the endocannabinoid system in many body organs and can damage the normal functioning of brain and body systems. SC-related side effects are mediated by cannabinoid receptor 1 (CB1R) and cannabinoid receptor 2 (CB2R) activation, producing deleterious changes in the brain and body.
Cannabis Use Disorder
Numerous people use cannabis without adverse effects. However, for some, health risks associated with cannabis are real. About two-thirds of people diagnosed with CUD have at least one other substance use disorder, most commonly involving tobacco or alcohol. About half have a psychiatric disorder—most frequently post-traumatic stress disorder (PTSD), major depression, or generalized anxiety disorder. Having a psychiatric disorder is associated with more severe CUD.
Adolescents, Young People, and Cannabis Psychosis
The association between cannabis use and psychosis has been known for more than 100 years. Teens have report hallucinations or paranoia more often if they smoke marijuana at least once a month, versus those who smoke once or twice a year. Epidemiological studies and, more recently, genetic studies, suggest cannabis use is a risk for later development of psychosis. The association is complex and factors such as adolescent use, THC dose, past trauma, and other environmental risks, as well as psychiatric symptoms like anxiety and depression, may accelerate the process.
More potent cannabis and more frequent use contribute to higher rates of psychosis, especially in young people. Experiencing one cannabis-induced psychotic episode increases a person’s chance of bipolar disorder or schizophrenia by nearly 50%, significantly higher than a psychotic episode induced by amphetamines, hallucinogens, opioids. or alcohol.
Considering Other Health Risks of Cannabis
Since cannabis has been used widely without FDA approval for years, many consider it safe. Unfortunately, recent studies show that cannabis use can lead to cardiovascular diseases, pulmonary (lung) diseases, cancer, asthma, anhedonia, and psychiatric disorders.
Cardiovascular and Stroke Risks
Cannabis use often leads to increased heart rate in healthy individuals. Frequent cannabis smoking may also significantly increase the risk of heart attack and stroke. A study reported in the Journal of the American Heart Association examined nearly 435,000 American adults to explore the relationship between cannabis and cardiovascular events.
The study found daily use of cannabis—predominantly through smoking—increased the likelihood of heart attack by 25% and stroke 42% compared to non-use of the drug. Less frequent use was still associated with increased risks. Weekly users showed a 3% increased likelihood of heart attack and 5% increased likelihood of stroke.
Cardiologists warn that use of the drug has sobering consequences for the cardiovascular system, especially in those with unrecognized cardiovascular problems. “There are now higher rates of young people with no obvious cardiac histories going to the emergency room with heart attacks,” says Yale’s D’Souza. Many ER visits occur within an hour of the individual consuming cannabis.
Cannabinoid Hyperemesis Syndrome
Cannabinoid hyperemesis syndrome (CHS) is a form of cyclic vomiting often accompanied by abdominal pain. It may occur during or within 48 hours of frequent and heavy cannabis use. CHS is a major reason for cannabis-related visits to the ER.
The condition may also be present in those who mistakenly assume that edible marijuana (as in gummies or baked goods) has the same rapid effect as smoked marijuana. For example, an individual may consume cannabis orally to no effect for several hours, then eat extra edibles, causing toxicity to the digestive system.
Surgical Risks
Individuals should tell a surgeon and anesthesiologist if they use marijuana. The American College of Surgeons points out that marijuana may affect the level of pain medication needed after surgery. It may also be difficult for surgeons to place a breathing tube needed for anesthesia in regular marijuana users. Frequent use of the drug can also cause breathing difficulties, such as bronchitis. Surgeons recommend ending the use of all marijuana at least 72 hours before surgery.
Psychosis
For more than two decades, Dr. D’Souza has studied the relationship between cannabis use and psychosis. Cannabis may induce short-term psychotic disorder (cannabis-induced psychotic disorder, CIPD) lasting days to weeks. This condition often requires clinical intervention. In Denmark, increasing potency of cannabis has been associated with increased incidence of CIPD. Interestingly, up to 50% of patients diagnosed with CIPD were rediagnosed years later with schizophrenia or bipolar disorder, suggesting CIPD may predict a chronic psychotic disorder. Researchers also note that with more frequent and heavier use of the drug and higher potency cannabis, the risk of CIPD is greater.
Treatment of Cannabis Use Disorder
No medication is approved by the FDA for the treatment of CUD. However, GLP-1 drugs, currently used to treat type-2 diabetes and obesity, may help. A recent study suggests that semaglutide (Ozempic, Rybelsus, Wegovy) may reduce the risk of cannabis use disorder. The rate of CUD recurrence was only 13.0% in patients receiving semaglutide compared to 20.4% in those who did not, a 38% lower risk with semaglutide treatment.
Conclusion
As cannabis becomes increasingly available, individuals need to realize the possible risks associated with cannabis smoking, teen-young adult use, regular use of the drug, and high-THC products. Note that cocaine is considered safe and effective for ENT surgery, and fentanyl for pain relief and as an anesthetic. Similarly, marijuana and cannabinoids may have benefits. Having a specific FDA-approved use in medicine, prescribed and supervised by expert physicians, is one thing; we have learned the opposite from the cocaine epidemic of the 1980s and the current fentanyl overdose death crisis. Still, users need to be aware of health risks and remember that self-medication has additional risks. It was physician Sir William Osler, a founder of Johns Hopkins Hospital, who first observed, “A physician who treats himself has a fool for a patient.” A patient who treats himself should be aware, as well.
