Interview with TV New Zealand about Cannabis Risks
Erik Messamore, MD, PhD
Anna:
New Zealand researchers recently voiced concern about a lack of data about the effects of cannabis. With the referendum later on this year, it’s important that you as voters can make an informed choice. So what exactly do we know about the effects of marijuana on its users? Erik Messamore is a psychiatrist at Northeast Ohio Medical University and he sees the risk of harm is real. He joins us now to explain, Eric, thank you for coming on the show this morning. The first question I have is actually a slightly curly one, I guess because you’re in favor of the legalization as I understand it, of cannabis products, but yet here you are to tell us about the risks of it. How does that balance each other out?
Erik:
Well, thank you for inviting me and yes, I am in favor of legalization and I’m also in favor that people know the risks. To me, banning cannabis makes no more sense than banning cigarettes or banning alcohol in the United States. We’ve tried to ban alcohol. That was a short lived experiment. We found that we couldn’t do it. It created a forbidden fruit and organized crime and it just doesn’t work. Telling people no is not effective. And in fact you could say that because of prohibition, cannabis has become more popular in the world than ever before. So I think we should have it available, but people should know about its risks just as well as they know about the risks of cigarettes.
Anna:
And when we talk about those risks, what sort of risks specifically are you talking about when it comes to the harm from smoking cannabis or using cannabis?
Erik:
Well, yes, when it comes to risk, people should get their risk information from independent scientific organizations and not from the people who are willing to profit from legalization. An organization called the National Academies of Sciences, Engineering and Medicine is an independent scientific organization and they identified actually 14 scientifically credible risks. The most common and the most serious of them are severe anxiety and panic attacks and psychosis, which is a form of extreme paranoia and even hallucinations.
Erik:
It’s also very risky for pregnant women to use cannabis during pregnancy. We know that babies that are born to women who use cannabis during pregnancy have about a two fold higher risk of being born, of a very low birth weight, meaning five and a half pounds or two and a half kilograms or less. Such babies also have double the risk of spending time in the neonatal intensive care unit. There are also risks of addiction or problematic use. There are risks that if children are in the house in areas where cannabis is legal that they are exposed to cannabis products or cannabis concentrates and several more, but those are some of the most important ones.
Anna:
There’s a whole range of risks you just talked about then, and I know from the notes that we have, there’s also some really staggering figures around cannabis use and its association with developing symptoms that mimic or appeared to be related to schizophrenia. What was it, if you have one copy of this gene that relates to developing, there’s a 250% higher risk of developing schizophrenia or something that mimics schizophrenia by the age of 26. 250%?
Erik:
This is correct. And some very interesting and very alarming risks data about cannabis risk came from New Zealand. The data that you mentioned came from a study known as the Dunedin cohort study. In 1972 scientists decided to track the lives of about 1,000 children born at Queen Mary’s hospital in Dunedin.
Anna:
It’s a very famous study, it’s developed some fantastic research. I know what you’re talking about.
Erik:
And so they’re followed for their entire lives. At 15 years old and 18 years old they were asked, have you used cannabis? And simply recording, yes or no. Of the ones that used cannabis before age 18 there were significantly higher rates of being diagnosed with schizophrenia or schizophrenia like diagnosis at the age of 26. Cannabis legalization advocates, the one that I called the optimist. I’m a legalization advocate as well, but I’m a realist, but the ones I call the optimists tend to say, “Well that schizophrenia risk is only a problem if you carry a risk genes.” And the Dunedin study showed that those risk genes are actually very common. So if you had two-
Anna:
50%, isn’t it?
Erik:
Yes, if you had two copies of the low risk gene, cannabis has no bearing on your likelihood for developing schizophrenia, but only 25% of the sample in Dunedin had that risk profile. Half, or 50% of the sample contained one dose of the risk gene and that conferred about doubling the risk of schizophrenia. And those 25% of the sample that had two copies of the risk gene had 1,000% higher risk of schizophrenia diagnosis by age 26.
Anna:
That’s a really extreme number that we’re talking about and I know that we’re talking about 50% of the population of that study that did have one copy of that gene. When you look at the range of risks associated that you’ve talked to us about, everything from, I know that there’s a higher incidence rate of being involved in a car crash right through to schizophrenia. Sorry, [inaudible 00:05:12] working there. What do you make then, knowing what you know, why would you support legalization? I know you said people should know about it, but why should we have access to a cannabis product legally?
Erik:
Because in, at least in my experience, people who want to use cannabis will acquire cannabis regardless. So you create a black market and you create legends around cannabis. So if cannabis is secret and forbidden and in the shadows, then people who love it will tell everybody about how much they love it. And that’s all you hear. If it’s out in the open, we can know about its risk. The schizophrenia is really no different than no more serious than cancer. And we tolerate cigarettes with knowledge.
Anna:
Just one more question, Eric. Just quickly because we, our bill, and I know you know a little bit about the legislation that’s being proposed with the referendum here. There is some concern from you, I understand, about the way that it is defined as a cannabis product and we need to be aware it’s not just a plant product necessarily that we could see higher concentration products like THC, vaping pens and the like, and that might have an impact on the range of side effects or the range of risk factors associated with it.
Erik:
Yes, the devil is always in the details and your bill in New Zealand is similar to laws or bills in the United States. Cannabis is defined very broadly, not just as a plant but as essentially any THC product, any derivative in any form, in any concentration. It’s kind of like legalizing beer but then finding out that alcohol or even pure or vodka are also called beer. So the risks go up as concentrations go up and so it’s wise to pay attention to that detail.
Anna:
Eric Messamore, thank you very much for your insight there. Psychiatrist at Northeast Ohio Medical University.
Speaker 3:
What a fascinating interview.
Anna:
Yeah.
Speaker 3:
Absolutely fascinating.
Anna:
And that drugs don’t know that they’re good or bad, that that’s not, they’re not out to get you. It’s just your decision when you take them or if you’re going to take them, what are the side effects that you could be subjected to? I can’t believe that risk factor for schizophrenia, 50% of us will carry one copy of that gene, and it’s a 250% increase in the risk.
Speaker 3:
A big decision for people to make-
Anna:
Yeah, it is.
Speaker 3:
… With referendum coming up. So we will look at this throughout the year, but that was a really fascinating interview. Thanks, Anna Burns.