Dr. Peter Grinspoon, an instructor in medicine at the Harvard Medical School, uncovers the truth behind medicinal cannabis use, and the medicinal benefits of cannabis for addiction treatment.

In addition to my disintegrating job as a primary care doctor, I work at the addiction clinic at my hospital. We take top-rate care of anyone struggling with addiction, no matter what their circumstances. We provide low-barrier access to treatment hoping to prevent overdoses and other complications, such as heart damage, skin ulcers, and blood infections. We help people reclaim their lives from the horrors of addictions which run the gamut from alcohol to opioids, benzos, methamphetamine, and cocaine. Many are simultaneously addicted to several of the above. It can be rough going.

I have been treating patients with medical cannabis for twenty-five years and I know that with the use of cannabis, patients frequently are able to cut down on more dangerous drugs such as opioids, Ambien, or benzodiazepines. This type of harm reduction is a win all around. But the field of addiction medicine hasn’t read this memo yet. They refer to cannabis as an “illicit drug” (putting it in the category of fentanyl and PCP) when it is currently fully legal for adult use in 24 states and is legal for medical use in 38 states. Cannabis is also legal, to varying degrees, in numerous other countries. One is left with the impression that any cannabis use is associated with psychosis, hyperemesis, addiction, tarnished lungs, a “gateway” to opioid addiction, heart attacks, premature babies, and amotivational syndrome.

For example, in the main chapter about cannabis from the textbook “The ASAM Essentials of Addiction Medicine”, the authors refer to “medical marijuana” with derogatory quotation marks, as if to denote that the entire enterprise is fake science that only a deluded hippy would believe in. Next, they state that patients “purportedly” benefit from its analgesic and antiemetic properties. Purportedly? Even the 2017 report from the National Academy of Sciences, Engineering and Medicine stated that there was “conclusive” evidence for these medicinal uses of cannabis.

To anyone who has ever used cannabis, it boggles the imagination that one might have to change to a job that “requires less technological acuity and is less cognitively challenging” because they use cannabis. In many cases, cannabis can help people think creatively and analytically. This question manages to incorporate two cannabis myths: first, that it makes you dumber and, secondly, that it saps your motivation. As an aside, I don’t think that heavy ketamine use, or particularly DMT, would particularly help your job performance. Hallucinating on the job and communicating with space elves is rarely helpful in the corporate context, but that wasn’t the correct answer,

Myth number one, the theory of “amotivational syndrome”, has always been nonsense, a creation of the War on Drugs, with no basis in reality. Some of the most motivated people throughout human history have been cannabis users (think of Astronomer and Pulitzer Prize winner Astronomer Carl Sagan, for one). I address this particular false claim in my recent book, Seeing Through the Smoke: A Cannabis Expert Untangles the Truth About Cannabis. In short, the reason a group of researchers was able to make it look like cannabis caused an I.Q. drop was that they didn’t factor in other things that can make kids do worse on standardized tests such as poverty, mental health issues, and, in some studies, tobacco, alcohol and other drug use. When a different group re-analyzed the same data, paying attention to these factors, the purported drop in I.Q. vanished.

Another practice question asked how many milligrams of THC in an edible can cause respiratory distress and a coma. The correct answer was that a 7.5 mg gummy (which is about the THC content of one puff of cannabis) is enough to cause respiratory depression and coma. To start, cannabis doesn’t cause respiratory depression or coma. There isn’t a significant concentration of cannabinoid receptors in our brainstems — which is the part of the brain that controls breathing. By contrast, there are abundant opioid receptors in the brainstem, and this is how opioid overdoes happen: you stop breathing.

During some gruesome experiments during the War on Drugs, the National Institute of Drug Abuse funded research that tried to kill, via respiratory depression, monkeys and dogs with astounding (and cruel…) doses of THC. They were desperate to prove that cannabis could be lethal. Even with hundreds of thousands of milligrams, the monkeys and the dogs lived on. This is the equivalent of something like 100,000 5 mg gummies taken all at once! If five hundred thousand milligrams couldn’t cause respiratory depression in animal species with nervous systems that resemble ours, then 7.5 milligrams of THC taken orally obviously couldn’t cause respiratory depression or coma. (The person who wrote this question might as well have been in a coma…).

There are known harms to cannabis use. It would be more helpful if the addiction curriculum focused the actual harms of cannabis, within a reasonable context of harms versus benefits. These harms are well-documented and well-researched. Anyone (who is sensible) would agree that, with cannabis use, there are:

Concerns over effects on brain development in teenagers, particularly younger teenagers
Concerns over safety in pregnant and breastfeeding women, including ill effects on the fetus/newborn
Concerns that cannabis can trigger or worsen psychotic disorders, especially in young adults
Concerns that smoked cannabis contains harmful combustion products
Concerns that people might get addicted to cannabis (though this is complicated; see my blog)
Concerns that smoked cannabis could help trigger coronary events and arrythmias
Cannabis Hyperemesis Syndrome
Concerns about driving under the influence of cannabis
Concerns about accidental exposures and nonfatal overdoses due to how strong and laxly packaged today’s cannabis is, especially edibles
Again — it is a question of context.

All medications have unwanted and unintended effects. For example, if I prescribe penicillin to treat a patient with strep throat, most patients will respond well. A small minority could have a serious allergic reaction. That doesn’t mean we don’t use penicillin but, rather, we discuss the potential harms with patients and use it cautiously and mindfully. We monitor them and promptly respond to any problems that arise. If we solely focused on the allergic reaction and didn’t factor in that most people recover from a serious infection, penicillin would look like a horrible drug! The same is true for aspirin: if we only consider ulcers and bleeding, and don’t factor in cardiovascular benefits, it would be considered a noxious poison, not a life-saving medication.

Of note, the problems in cannabis communication do not just lie with the cannabis skeptics and prohibitionists. Cannabis zealots must give up on fanciful claims such as “cannabis is natural and harmless”, “cannabis cures covid”, or “cannabis cures cancer.”

It doesn’t help anyone or anything to present a drastically one-sided view of any medicine or medical treatment. It confuses everyone, lessens credibility and believability, and makes it difficult for patients to find and trust physicians as legitimate sources of knowledge. As it is, much of the information out there on cannabis is incredibly contradictory. Why add fuel to this intellectual fire?

The type of misleading presentation of information that I have documented above makes it much more difficult for doctors to advise patients about medical cannabis use. They don’t know enough to even to carry on a sensible conversation. Patients then go elsewhere to obtain their practical information, such as to “budtenders” at cannabis dispensaries. Budtenders tend to be nice and enthusiastic cannabis connoisseurs, but they aren’t medically trained and shouldn’t be giving medical advice. They might not be aware of the harms in pregnancy, or the risks of psychosis, and they certainly wouldn’t know about potential medication interactions.

In this vacuum of knowledge, it is very difficult for doctors and patients to communicate on this issue. Most patients will just clam up in the face of any perceived stigma or judgment. It presents an unnecessary and self-inflicted barrier. If doctors view cannabis along the lines of PCP and heroin, due to a steady stream of misleading education, it is difficult for them not to view all cannabis use with stigma and judgment. Even doctors with extraordinary bedside manner can’t help but convey these feelings on a subconscious level.

This lack of communication is dangerous. Patients are much less likely to ask for help if they start to suffer from any of the harms listed above. If they are slipping into addiction, they won’t feel comfortable bringing this up. If a doctor asks, as part of screening (along with alcohol and tobacco), “do you use marijuana? patients will lie.

I know hundreds of cases where this has happened. Without a discussion and accurate knowledge, doctors can’t warn about potential medicine interactions. Doctors can’t even inform patients about the basic and elemental harms of cannabis – such as harms in pregnancy — if they aren’t discussing this issue with their patients. If the harms are exaggerated, as they have been during the entirety of the War on Drugs, patients simply won’t believe them.

How to move forward? We need to come to some sort of middle ground on cannabis. We should all be able to agree on a certain patch of common ground. Cannabis can be a helpful in alleviating symptoms of chronic pain, anxiety, insomnia, chemotherapy induced nausea and vomiting, PTSD, fibromyalgia, colitis, and spasticity in multiple sclerosis (though it is often unclear what the long-term impact of the cannabis use is on these diseases). The harms are real and it is vitally important to educate patients on them. From this growing patch of common ground, we focus on the science that is coming out daily, and we can then evolve our common beliefs about cannabis. This process needs to be insulated from both the industry of prohibition (law enforcement, private prisons, etc.) which profits so much from cannabis criminalization, as well as from the influence of the cannabis industry.

We all agree (except for the RFK wingnuts…) on the benefits of vaccines and antibiotics. Why should cannabis be any different. We must teach doctors about the endocannabinoid system (the endogenous system of neurons and transmitters via which cannabis works its effects). This would help doctors understand cannabis harms as well as benefits. We need to teach physicians how to advise patients on dosing and potential side effects and drug interactions. All doctors need to find a way create a climate in which patients can talk about cannabis without feeling judged or criticized.

The medical profession as a whole is inching forward. Recently, the Journal of the American Medical Association (JAMA) published an article calling for the development of core competencies for educating medical students about medical cannabis. This both tacitly assents to the idea that cannabis is a helpful medicine and starts to address the problem that doctors urgently need to get up to speed on this issue to be helpful to their patients.

My late father had been working on this issue for fifty years, since 1973, when his masterpiece “Marihuana Reconsidered” was published. We are not there yet, in terms of full legalization (so we stop arresting brown and Black people for nonviolent possession of cannabis). We are not there yet in terms of universal access to medical cannabis so that patients don’t needlessly suffer. We are getting there. Education and accurate information are cornerstones of this process. Of all people, our addiction specialists should lead the way, instead of muddying the waters.

Dr. Peter Grinspoon  teaches at the Harvard Medical School and has been a life-long advocate for the healing properties of cannabis.