The Top Nine Myths About Cannabis That Your Physician May Still Believe

The War on Drugs has cast a long shadow…

Doctors are clearly behind the eight ball in terms of understanding the practical applications and medicinal benefits of cannabis. This makes for difficult, painful, and unsatisfying conversations with patients. Fortunately, a clear majority of physicians are supportive of the use of medical cannabis and a large subset is hungering to become better informed. Unfortunately, there is a small but vocal cadre of old-school addiction “specialists” and drug warriors who keep pumping out an unhelpful view of cannabis as unequivocally harmful and entirely without benefits. This pollutes the dialogue and leaves many in a confusing intellectual no man’s land. The truth, as always, is somewhere in between the two poles.

We are getting closer to the day when we can all come to some common ground about cannabis. For benefits, few sensible people would disagree that it can help alleviate suffering from chemotherapy induced nausea and vomiting, chronic pain, anxiety, and insomnia. Many would further agree that it can help alleviate spasticity in MS patients, pain in fibromyalgia patients, and gastrointestinal symptoms, such as with the discomforts of irritable bowel syndrome. Likewise, we might all agree that, except under certain limited circumstances (e.g., severe autism or fatal cancer), that teens shouldn’t use cannabis, and that it must also be avoided by pregnant/breastfeeding women and by people with a history or family history of psychotic disorders. It should also be used with great caution, if at all, in cardiac patients.

In a perfect world, it would not be smoked, even though this is a highly effective way to alleviate most symptoms. Cannabis smoke contains toxic combustion products which can’t possibly be healthy, though it is less dangerous than cigarette smoke. Cannabis is more safely consumed via a tincture or an edible.

During the seven or so decades that our War on Drugs spewed out misleading propaganda about all drugs, doctors were solely exposed to the negatives of cannabis. Many of these were either fabricated (e.g., “amotivational syndrome” and the “gateway theory”), magnified, or presented in a decontextualized manner which made them seem more ominous than reality dictates.

My education, in medical school, which I discuss in my book, “Seeing Through the Smoke: A Cannabis Expert Untangles the Truth About Marijuana”, was abysmal. Many of these myths and misconceptions remain.

Currently, there isn’t much neutral education going on about cannabis. Some education is sponsored by people who are “pro” cannabis in the form of lucrative commercial endeavors. Other cannabis education is provided by people who are “anti” cannabis. A recent segment on medical cannabis at a continuing medical education session at my institution, Harvard Medical School was, at best, entirely pathetic. I complained and was ignored, and they continue, to this day, with this embarrassingly unhelpful nonsense.

The following are myths and misconceptions that commonly remain, hammered over the decades into the brains of physicians. Most of these doctors haven’t themselves treated patients with medical cannabis and haven’t seen, firsthand, how dramatically it can help or harm.

Myth One
People smoke medical marijuana which means it isn’t a safe medicine (or a medicine at all).

Reality:
A friend of mine, a psychiatrist, once yelled at me, “how can a burning plant be considered a medicine?” He then stormed away. There are numerous ways to consume cannabis that are safer than smoking it. These include ingestible forms such as edibles and tinctures which are not harmful to the lungs, and which allow careful control of dosing. Most of the harms of cannabis that have been demonstrated were demonstrated by studying smoked cannabis. We have much less evidence that edibles and tinctures are dangerous. As with other drugs and medications, there are safer and less safe ways to use cannabis, and smoking is clearly less safe than other consumption methods. Many patients prefer to smoke cannabis because it provides immediate symptoms relief.

Myth 2:
There isn’t evidence that cannabis is an effective medication.

Reality:
There currently exists an abundance of evidence, particularly “real world evidence”, that cannabis helps with conditions such as chronic pain, anxiety, insomnia, nausea, spasticity in M.S., and many of the other conditions it is commonly used for. It doesn’t work for everything and anything, as some advocates believe, such as curing cancer or Covid. It is simply not true that there isn’t evidence that cannabis is an effective medication for many conditions. The evidence base grows every day. This is especially true as more neutral research is emerging out of the shadows of the War on Drugs which, for half a century, only funded studies that demonstrated harms of cannabis.

Myth 3:
Cannabis is as addictive as alcohol.

Reality:
Cannabis certainly can be addictive, but it is significantly less addictive than alcohol and is also less addictive than opioids and tobacco. It is likely less addictive than stimulants and benzodiazepines. While an addiction to cannabis can be incredibly destructive, isn’t as dangerous as alcohol or opioid addiction, as it generally isn’t life-threatening. Cannabis is about as addictive as coffee is -- which is not insignificant (as I chug away on my sixth cup of the day while writing this).

Myth Four:
Cannabis lowers I.Q. points in teens.

Reality:
The initial studies, conducted during the War on Drugs, appeared, at first glance, to demonstrate a drop in I.Q. These studies received a lot of media attention. When they re-evaluated the data, and factored in socioeconomic factors (e.g., poverty, educational attainment), there was absolutely no drop in IQ. The research tended to be on populations of disadvantaged teens. What this research came down to is that poor, disadvantaged kids, who tend to use cannabis more because their lives are miserable, tend to do worse on standardized testing than white, wealthy kids. There is conflicting data, which is mostly in the form of neuroimaging studies, about potential effects of heavy cannabis use on teenage brains - this does need to be clarified and is a great argument for teens to “just say wait”.

Myth 5: Cannabis causes lower motivation.

Reality:
Cannabis doesn’t lower motivation. This was a myth spread by the widely criticized DARE program that tried, unsuccessfully, to scare people away from cannabis and other drugs, by spreading exaggerated claims. Sometimes miserable and depressed people can use cannabis to blunt their pain, and it certainly can appear as if the cannabis is sapping their motivation. Some of the most motivated people throughout history – scientists, musicians, writers, artists -- have been cannabis users, and demonstrate, by example, that cannabis can contribute to motivation.

Myth 6: Cannabis causes lung cancer.

Reality:
Smoking cannabis is clearly not healthy for the heart or the lungs, as the smoke contains unhealthy combustion products, such as benzene, tar, and carbon dioxide. Yet, cannabis has not been linked with lung cancer or emphysema/COPD. It does cause a chronic bronchitis because of the irritation of the lungs from smoke. It can temporarily worsen asthma. Cannabis taken through other modes, such as tinctures and edibles, is not linked with any lung problems. It is not impossible that cannabis will be linked to lung cancer in the future, which is one of the reasons we advise people not to smoke it, though cannabis smoke is clearly safer than smoke from a cigarette.

Myth 7: A positive drug test means you are intoxicated.

Reality:
This comes up commonly, in pre-employment drug screens or after auto accidents. Cannabis is “fat soluble”, which means that it sticks around in our fat cells, and it can be detected in the urine for weeks, or even a month, after use. A positive test generally means that the person used cannabis within the last few weeks. It does not mean that they are acutely intoxicated, or even that they were intoxicated within the last day or two. In this respect, is totally different from alcohol, where the blood levels directly correlate with the level of intoxication.

Myth 8: Cannabis causes schizophrenia.

Reality:
Cannabis can contribute to the triggering of severe psychosis, most commonly in teens and young adults. It also might precipitate symptoms of schizophrenia earlier than they might have occurred in people who are genetically prone to develop schizophrenia. This is a concerning effect of cannabis because the longer one can delay the onset of schizophrenia, the more “adult” life skills can be learned, and the more independent and functional a person can become. However, cannabis doesn’t “cause” schizophrenia. We know that because the rates of schizophrenia have been relatively stable worldwide over the last seventy years, while the number of cannabis users has gone up 1000-fold during this timeframe. If cannabis “caused” schizophrenia, we would have to see a vast increase in the number of cases of schizophrenia. This has not been observed.

Myth 9: Using cannabis makes you dumber.

Reality:
The data has been confusing over the years. On the one hand, cannabis is known to cause a transient decrement in short-term memory, which contributes to the stoner stereotype. This effect, which is real, fully resolves after a few hours. It is not safe to drive under the influence of cannabis as your judgment might be off. On the other hand, some studies of medical cannabis patients show that cognitive functioning significantly improves, across several domains, after the patients started using medical marijuana. There are many theories as to why this improvement was observed for medical patients but not for recreational marijuana patients. One likely explanation is that when sleep and pain are better controlled, cognitive functioning improves.

Hopefully, as we address these myths about cannabis and as more research pours in, doctors and patients can finally get onto the same page. This will allow medical patients to communicate with their doctors without fear and to utilize it without stigma and judgement.