Kevin P. Hill, M.D., M.H.S, is an addiction psychiatrist, Director of the Division of Addiction Psychiatry at Beth Israel Deaconess Medical Center (BIDMC) and an Associate Professor of Psychiatry at Harvard Medical School. Hill is an investigator focused on evaluating the use of marijuana for psychiatric conditions as well as the medications and behavioral interventions that might improve available treatments for those wanting to stop smoking marijuana. The author of a review of current trends in medical use of marijuana in the August 2019 edition of the Journal of the American Medical Association, Hill also published a landmark study in that journal in 2015 and the book Marijuana: The Unbiased Truth about the World’s Most Popular Weed (Hazelden, March 2015).

We asked Dr. Hill to weigh in on the popular debates over medical and recreational marijuana.

Q: From anti-aging skin salves to pooch-calming doggy treats, CBD (cannabidiol) now appears in just about every product you can think of. Are there any real benefits to CBD, or is it 2019’s most prominent snake oil?

We have people using it for just about everything. Unfortunately a lot of those applications are just not based on any evidence. Plenty of people say this whole thing is sham and there’s no medical value in CBD – I am not saying that. I am very excited about CBD and I recommend it to patients for the treatment of anxiety. CBD has been approved by the FDA for treatment of a two rare types of epilepsy, and there are at least two studies that show it to neuropathic pain. It’s very promising.

But we also know the product reliability is poor. A 2017 JAMA paper showed that only 30 percent of commercially-available CBD products were accurately labeled.  You also can get THC (the chemical in marijuana responsible for the high) in products not labelled as containing it– that’s relevant because you could end up with a positive urine drug screen without even knowing you used THC.

Cannabidiol on the whole is probably pretty safe, but you can take a safe medication and make it dangerous if you’re using it in the place of evidence-based meds. If someone has bad depression and they take multiple medications, if that person says, “I saw CBD on TV, and I think this is the answer to my problems,” well, that can be really dangerous. If you’re using it, you want to do that in collaboration with your physician, ideally.

Q: What are some of the major misconceptions about cannabis and its medical and recreational uses?

Hill: I think a major misconception about this subject is that people on both sides try to make it seem as though the whole issue is simple – it’s either good, or it’s bad. The marijuana plant itself has hundreds of chemicals. It’s not simple. There are about 400 chemicals in the plant, 140 or so of which are cannabinoids, and yet we only ever talk about two of them – THC and CBD. There’s a lot of complexity here and we haven’t even begun to scratch the surface of it.

My take-home message is, when people try to make this sound simple, beware. It is really not simple.

Q: What’s something you wish more people knew about using marijuana products?

We don’t often talk about the dose. A lot of the harms we associate with cannabis – the chance of psychosis, loss of IQ in younger users – we don’t talk about how important the dose is.

One of my greatest frustrations is the lack of education around edibles. A typical brownie has about 100 mg of THC in it. An average user wouldn’t want to consume more than about 10mg of THC in an edible – limiting them to about one-tenth of a brownie. I don’t know about you, but if I’m eating a brownie, I’m probably eating the whole thing.

We’ve done a poor job educating people. They don’t understand edibles and serving sizes and they also don’t understand that the onset of action for edible THC – that is, the amount of time it takes to feel the effects – is about 30 minutes. So they take a bite, nothing happens; they take another bite, nothing happens; after half an hour, you might have taken 4 or 5 times the dose you’re supposed to. That’s a recipe for disaster. No one’ going to die, but people end up in the ER and that should never happen.

Q: What impact has legalization had on youths’ use of marijuana products?

It’s a battleground. I have a moderate approach. I have concerns, but the data so far has not suggested that youth use has increased in the context of legalization. What has changed, is the perception of risk around using marijuana has declined.

We do a good job of educating kids about tobacco and alcohol, but having the perception of risk go down in the context of these policies suggests to me that we have not done a good job educating kids about cannabis. I think that stems from the anti-cannabis people being afraid to talk about it in a sensible way, and the pro-cannabis people using a lot of marketing language about its benefits which is somewhat irresponsible.

Q: Has legalization and the de-stigmatization of drug use had any impact on the ongoing opioid crisis?

There are now six or seven observational studies suggesting cannabis policy – both medical and recreational – suggests we may see fewer opioid-related deaths, and also fewer opioid prescriptions in regions where cannabis is available. That to me suggests that smart policy around cannabis may be a potential part of a solution – not the solution – but part of the solution to the opioid crisis.

Some are advocating that people with opioid use disorders can use cannabis to get off the opioids. I’m not saying that. But I am suggesting that if someone is taking opioids for chronic pain, we can question if opioids are the best treatment for them, are they working as well as they should, as safely as possible? I think cannabis could be part of a solution for patients in these cases. But if you’re struggling with street drugs, injecting fentanyl, I’m not going to suggest you switch to cannabis and all your problems will be solved.

If I were in charge of a state or a nation, I would want to measure who is using medical cannabis, what are their outcomes like – do we see fewer overdoses and less addiction among that population? I suspect access to cannabis can be a positive thing, but we need data before we can say that for sure.

Q: Speaking of data, is there an organized effort to study marijuana and its products in a rigorous, methodical way?

CBD is clearly a compound of interest and it’s not being researched as much as I would like it to be. There are no serious randomized control trials looking at CBD for pain, and that would seem to be low hanging fruit. Given the intense interest surrounding cannabis and CBD, the rate and scale of the research must increase.