[music]

Brian Lehrer: It's The Brian Lehrer show on WNYC. Good morning again, everyone. As legal recreational cannabis becomes more common in our area and around the country, there are more articles and more doctors speaking about the benefits, health-wise, and the risks. We're going to have a conversation that tries to unpack some of both right now with our guests, Peter Grinspoon, MD, instructor in medicine at the Harvard Medical School and author of an upcoming book called Seeing Through the Smoke: A Cannabis Expert Untangles the Truth about Marijuana. Dr. Grinspoon, thanks for coming on. Welcome to WNYC.

Peter Grinspoon: Thanks for having me.

Brian: Listeners, we can take some phone calls for Dr. Grinspoon on this your questions about health benefits and health risks of cannabis. 212433-WNYC, 212-433-9692 or tweet @BrianLehrer. Well, as you know, Dr. Grinspoon, the first legal use of cannabis for a number of years and a number of states was what they called medical marijuana. What are some of the most proven medical uses of cannabis according to the scientific literature?

Peter: Well, it's interesting. Proven is a little bit of a loaded word, which I talk a lot about in my book because, unfortunately, because of the war on drugs, most of the research, all of it was focused on finding harms than benefits because they needed to demonize marijuana drugs. We have a lot more research into the harms than into the benefits. In terms of the proven benefits, very few people would deny that it helps people who have cancer with the chemotherapy, the nausea, the vomiting, the lack of appetite, the pain.

Chronic pain is another very big and well pretty agreed-upon use of cannabis. Nerve pain conditions like fibromyalgia, which are the big pain syndromes that don't respond to anything else. Cannabis not only helps you with the pain but it also helps with your perception of pain. It doesn't bother you as much. It also helps with your anxiety, your sleep, your quality of life. It really helps chronic pain people quite a bit.

Insomnia is a very big use for cannabis. People find that many of them especially in low doses, especially with CBD on board, not just high doses of THC, they find themselves gently drifting off to sleep. You can make a good argument that cannabis is safer than many of the sleeping medications that we commonly use like Ambien. Then people with multiple sclerosis, it helps with their spasticity and some of their bladder problems. The list goes on and on. Many people use it for anxiety. That's a little bit more controversial. Those are the main uses of medical marijuana, but again, there are hundreds of them. I could spend two hours just answering that one question.

Brian: Listeners, you can call with your anecdotal experiences of using medical marijuana and what it has done for you or on the other side, instances where you think using marijuana has caused you a health problem or a question for Dr. Grinspoon. 212-433-WNYC, 433-9692 or tweet @BrianLehrer. Anxiety is an interesting one because it can exacerbate anxiety or it can alleviate it, right? Depends on the individual and the circumstances.

Peter: Absolutely. It depends on the individual. It tends to be considered what's called biphasic, meaning it has a different effect at lower doses than at higher doses. Many people enjoy cannabis to lower their anxiety at a low dose. At a higher dose, especially for example, if people take an edible that's too strong and they're not familiar with cannabis, it can cause a [inaudible 00:04:14]. It can cause anxiety attacks. It can get your heart rate and your blood pressure up, which is very dangerous if you have heart problems.

It's complicated with anxiety because millions of people in this country use it successfully for anxiety but they can't use it at all because any level makes them anxious, and you have to be very careful with the dosage because the main way to get in trouble with cannabis is to take too high a dose and the main symptom you get with too high dose is very bad anxiety, which is complete [inaudible 00:04:45]. Yes, it's all about starting slow and keeping the dose low.

Brian: We saw that you had a Harvard health article about findings that access to medical marijuana decreases opioid prescriptions. The old language or the old smear on it, if you will, is that it's a gateway drug to more dangerous, harder drugs. What's this finding that access to medical marijuana decreases opioid use?

Peter: Well, that's a complicated question. I take it very personally because I'm 15 years in recovery from opioid addiction and cannabis very much helped me more than anything else did with the withdrawal symptoms when I was trying to get off opiates. I think that cannabis is very useful in that people can use it instead of opiates for chronic pain. They can use it with opiates for chronic pain to use a lower dosage of the opiates. A lot of the trouble you get in with opiates is dose related. That's great harm reduction. People can use it for the withdrawal symptoms if they're trying to get off or lower down on the opiates. It's very effective.

I don't recommend it specifically to get people off heroin or if they're addicted to opiates because we have better data for the medications, methadone, and suboxone. Both of those medications reduce overdoses and deaths by 50% to 80%. I don't use it instead of methadone or suboxone because we don't have the data, but I very much use it for patients for chronic pain and there have been dozens if not hundreds of patients, probably hundreds that have gotten off of opiates or down on their opiates. With 100,000 people a year dying of opiate overdoses, if we have this other relatively non-toxic medication, cannabis, that can treat people's chronic pain and improve their quality of life, it's no wonder that many people are substituting, especially as it becomes increasingly illegal, destigmatized and available.

Brian: On the health risks side, one of the studies we read preparing for this which came from Ottawa Hospital in Ontario, Canada links smoking marijuana to airway inflammation and emphysema. Certainly, people would say that about tobacco smoking, especially if you smoke a lot of cigarettes per day or smoke for a long time on a regular basis. Do you know the data on marijuana smoking? One might push back at the beginning of this and say, "Well, most people who smoke marijuana, maybe they'll smoke a joint in a day or a few joints a week. It's not enough to cause emphysema or lung cancer like tobacco has caused in so many people." Where would you enter that conversation? What does the data show?

Peter: Well, first of all, that study was very flawed. It didn't really distinguish well between the cannabis smokers and the tobacco smokers. They use people that smoke both. I don't think this study showed anything. It's been fairly well documented that cannabis does not cause emphysema. Smoking cannabis does not cause lung cancer but smoking cannabis does cause an acute irritant bronchitis, and it can't possibly be good for your lungs to smoke cannabis.

No doctors recommend smoking cannabis. If you need to inhale it, we recommend using a dry herb vaporizer where you heat it up much lower and you don't get any of the combustion products. I agree that smoking cannabis is bad for you and I never recommend it. Again, there are other inhalational techniques such as the dry herb vaporizer.

Brian: That's just what we commonly call vaping these days, right?

Peter: Yes, but vaping is a little complicated because there are the vape pens that you get in the dispensary that have the oils, and those are pretty irritating to the lungs. Then there are these little inexpensive devices you can get where you grind up the cannabis and then you just heat it up to like 400 degrees instead of incinerating it at 1100 degrees and it's high enough to extract the cannabinoids medicinally but it doesn't give you the tar, the benzene, the polycyclic aromatic hydrocarbons that you get when you burn it. There's a way to heat it up without burning, vaporizing.

There are two different types of vaping. The pens I think are pretty irritating to your lungs. Every time I've tried one of those, I feel like my lungs have been gone over with sandpaper. Then there's the dry herb vaporizers, which you have to grind it up and put it in and press the button. It's a little bit of a ritual but those are a much safer way to inhale. There are two different ways to vaping. One of which-- Again, doctors often recommend specifically because we don't think it's good for your lungs to smoke it. Under the tongue tincture is a very common way to take it.

An edible if you're careful of the dose is very good. They now have suppositories, inhalers like asthma, skin patches, topical ointments. There are many nasal sprays. There are many other ways to take it. If someone smokes it once a week at a party, it's probably not going to hurt their lungs but if it's a medical patient who's using it every day over and over again, we certainly don't want these people smoking it.

Brian: Harold in Brooklyn has a story. Harold, you're on WNYC. Thank you for calling in.

Harold: How are you, Brian? Long time second time.

Brian: Glad. You're on.

Harold: My story is I'm a bartender in Brooklyn and I've been an alcoholic for maybe like 10 years. I was and I just quit drinking for the first time in my life about three months ago. Well, I know it was three months ago end of week, and [inaudible 00:10:21] A lot of that success to cannabis, its legalization in the state, accessibility, the lack of stigma with purchasing it and using it in public.

Then I've also had chronic GI issues my whole life that I'm in and out of doctors' for that I use cannabis to alleviate problems of. It's also given me some lung issues because I have a messed up pulmonary system, but I've switched to vaping it. I bought a nice vape and I use that but that's my deal. Accessible, affordable, non-stigmatizing cannabis is really helpful for me and my journey away from alcoholism.

Brian: Harold, thank you so much. Diana in Queens, you're on WNYC. Hi, Diana.

Diana: Hi, Brian. Thanks so much for having this show. It seems like there's been so much different information out there. I just wanted to share a story about my mom who's 95. She has pretty severe dementia and anxiety as a result of the dementia. We have tried different things for her for the anxiety, but so many of the side effects of those medications are just terrible. It's just making her completely out of it, sleepy. We have been treating her for three years with THC twice a day in a honey form. It's nothing short of miraculous. She becomes talkative. She's less anxious. She's engaged so much more so than she would be without it, and it has just become a lifesaver.

Brian: Diana, thank you for that story. I think on the other hand we're going to hear from May in Yonkers, you're on WNYC. Hi, May.

May: Hey, there. I really appreciate the previous callers and your guest's perspective on its potential benefits, but as a psych nurse and through personal experience, I see a lot of folks using it. A lot of patients coming in with exacerbations of their mental health conditions. It's almost consistently with cannabis use almost without exception. I think a lot of folks use it to self-medicate for anxiety and even with insomnia and get a lot of blowback anxiety paranoia et cetera.

Even as functional as it can be for sleep, the next day a lot of irritability. I just think that there may be a lack of respect for the power of this natural medicine. As the doctor was saying, overdosing not respecting a minimum dose use and the effectiveness of that. That's been my experience.

Brian: Can you get specific at all about the kinds of mental health issues that get exacerbated in your experience as a psych nurse?

May: Yes.

Brian: Or how it expresses?

May: I think a lot of folks are using it to allay their anxiety and of course, anxiety is typically chronic. I think it actually exacerbates it. I think it can mitigate it in the immediate use and then it can create an exacerbation after the fact and contribute to paranoia and delusions and magnify them. Even in cases with just pure anxiety, I really think it has a magnification effect after the fact. It's not always obvious to see it because it can lessen the anxiety in the immediate and so it creates this chronic use impact because it's lessening and then exacerbating and so it's a cyclical thing.

Brian: May thank you very much for your call. I appreciate it. Another one like that, Ellen in Princeton, you're on WNYC. Hi, Ellen.

Ellen: Hi. How are you? I'm actually a physician as well and something that my colleagues and I talk about is the potential for cannabis to unmask proclivity or predisposition to schizophrenia among youth, like teenagers and young adults. I'm curious for the doctor whether there is a really hard data that cannabis can predispose young people to schizophrenia or psychosis or unmask a predilection towards that, and if so would you recommend limiting its use to a certain age group?

Brian: Thank you, Ellen. Dr. Grinspoon?

Peter If I could just say for the first caller congratulations on your recovery, and yes a lot of people are using it as an off-ramp, a gateway off of other addictions. For the second caller, I want to say it can be very helpful for elderly people. When my dad was suffering from dementia, it was incredibly helpful for his mood and his anxiety. For the third caller, I completely agree that it can destabilize people with psychosis and it can make anxiety disorders worse. I agree with her it does make people feel better. Same with depression, it makes you feel better but the question is what happens over time? Does your depression get better, worse, or the same? I think these are questions that we really do need to elucidate further.

It depends a little bit on your vantage point because if you're a psychiatric nurse, you see the train wrecks. Whereas if you're a primary care doctor like I am, you mostly see people who are using it with good benefit for anxiety. It's just like any drug for many people at works and some people have a very bad reaction to it and they need to be monitored closely. That's why I prefer to prescribe cannabis as part of my primary care practice where very close follow up with my patients. Not these like card meals where they give you a card and never see you again. I think the medical follow-up is necessary.

For the fourth caller, the whole psychosis thing is very interesting. Cannabis certainly can cause a temporary psychosis. It can cause a drug-induced psychosis just like alcohol and steroids can, that could last for weeks to months. It can precipitate schizophrenia earlier which is really bad because the later a person gets schizophrenia, the more they could develop their life skills and their adult skills and they have a better trajectory.

These are all side effects and consequences of cannabis that we have to watch very carefully. We don't prescribe it typically to people with schizophrenia with bipolar, with a family history of psychosis. At the same time, some people think that cannabis causes schizophrenia. I think it just people who are pre-schizophrenic are self-medicating with cannabis. The cannabis can help precipitate the schizophrenia.

The rates of cannabis use in the 1950s worldwide were in the tens of thousands. Now, the rates of cannabis use worldwide are in the hundreds of millions. The rates of schizophrenia have stayed stable at about 1% over the last 50 years. It's literally impossible that cannabis is "causing schizophrenia." What they've seen is that people who have a genetic tendency, who are predisposed to schizophrenia that could be triggered earlier by cannabis. Which is why again it's really important who you prescribe it to and that you screen them for their medical history and their family history because cannabis isn't for everybody and it's more dangerous for some people than other people.

Then the final comment I'll say is just like with many drugs, it's a very small minority that gets psychosis but teenagers are particularly susceptible to getting addicted to cannabis and they're particularly susceptible to having psychotic reactions. We work really hard to delay when people start using cannabis. We say to teenagers, we don't say just say no, we say just say wait because if there's one thing that both sides or the adults on both sides agree to it's that teenagers shouldn't be using cannabis.

Brian: A listener on Twitter asks or writes, ask about different strains and different effects. It's not all the same and they do sell different. It's common I think in the dispensaries that they label things sativa which is supposed to be more of an up and indica which is supposed to be more of a down. Do you find them to be medically different?

Peter Different types of cannabis are definitely medically different. They're 500 different components of cannabis. The main one being THC which causes the high and CBD which helps for anxiety and pain and insomnia but there are 500 components. Different types of cannabis smell different, they taste different when you make an edible or when you smoke them and they have different effects.

Now, strains isn't really the right name. We tend to use chemovars at least the medical cannabis people do because it's really a question of like what's in the cannabis. There's a lot of advertising with strains. If you notice they all have the same description causes a nice euphoric high followed by a relaxing full body feeling of peace. They all have the same description. I think there's a lot of BS and advertising about the difference between the strains, yet at the same time the strains are different. Indica and sativa is complicated. It used to be the indicas were a short bushy plant that caused [unintelligible 00:20:05] relaxed to be in the couch. Sativas were these tall, rangy plants that caused a very uplifting high if you want to go out dancing or do some writing or go out with friends. During the war on drugs, the Reagan years, the growers hybridized combined the two plants because you could see the sativas from the sky when the Reagan's helicopters were looking for cannabis growers to bust.

Most of the cannabis you get is actually a hybrid. You don't really get an indica or sativa. It's a botanical classification, though, I think they just still use the words indica and sativa exactly as you mentioned it. Indica to indicate relaxing for muscle pain, for sleep, for anxiety. Sativa for high energy, for going out. There aren't really indica and sativa. The consumer has to be educated because there's just a lot of advertising, now it's a business, there's a lot of nonsense, but at the same time, there really are differences between the strains, which is why it's really important. Two things, one is to work with, if you can, a provider that knows about cannabis so they can help guide you. It's inappropriate for the dispensary workers, the "budtenders", to be giving medical advice about the stuff. At the same time, it's inappropriate how little physicians know about cannabis and how little they're able to actually help patients. We're really interested in educating physicians. [unintelligible 00:21:27] [crosstalk]

Brian: Physicians to know about-- Oh, go ahead. You want you to add a second important thing. Go ahead real quick.

Peter The most important thing is that patients and doctors need to communicate a lot better about medical cannabis. A lot of doctors haven't been welcoming about the subject. Patients have felt stigmatized. Patients need to tell their doctors about their cannabis use, and their doctors need to listen without judgment because they are medication interactions.

If someone, for example, uses cannabis every day, they need more anesthesia, which is not a big deal unless the anesthesiologist doesn't know about it. The most important thing is that doctors and nurses and patients all communicate a lot better without judgment and without stigma. That would make everything so much safer.

Brian Lehrer: Any other major drug interaction that people should know about?

Peter Well, for CBD, for example, one in seven Americans are on a CBD product. One in three Americans have tried a CBD product. CBD works exactly like grapefruit juice in that it competes for the liver enzymes and can raise the level of other medications in your blood. Not a big deal unless it's a medication that has to be within a narrow therapeutic range, like a blood thinner, an antiepileptic, an immunosuppressant.

It just all speaks to the point is that the doctor and the patient has to be working together, and the doctor needs to know these med interactions because so many people are on CBD, and the patient has to let the doctor know that they're taking CBD. It's all about communication.

Brian: We will leave it there. Obviously, there are a lot more questions that we could ask and that he could answer about health benefits and health risks of cannabis. We've got a lot of information on the table here. We thank Dr. Peter Grinspoon, instructor in medicine at the Harvard Medical School and author of the upcoming book Seeing Through the Smoke: A Cannabis Expert Untangles the Truth about Marijuana. Informative. Thank you so much, Dr. Grinspoon. We really appreciate it.

Peter Thanks for having me, and thanks for the great questions.

Copyright © 2023 New York Public Radio. All rights reserved. Visit our website terms of use at www.wnyc.org for further information.

New York Public Radio transcripts are created on a rush deadline, often by contractors. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of New York Public Radio’s programming is the audio record.