We have this attitude in our society that it's sort of a benign drug.
All three of my sons claim that their smoking marijuana in high school with their friends brought on the symptoms of psychosis. Well, I'm sure that it did not help because I have read that if they already have the structure in their brain, the neurons in their brain, they are going to be schizophrenic, then the use of drugs can make it come on earlier.
My doctor, who is probably in his late 60s now, he says he knows for a fact that marijuana brings on psychosis. He says, "why don't they ask me? I've been treating people for this all my life."
We went to a family sort of training thing that they had. It went on for several weeks. So there were quite a few people. And one of the first questions the facilitator asked was about marijuana and and how many people here. Their loved one first started to show symptoms of psychosis after marijuana use and almost every hand went up.
In addition to just the health efforts, it's made their treatment much more complicated. Some of them, they'll be admitted to a hospital because they're off meds and they say, well, we can't do anything until we use marijuana because it complicates all our observations. I'm thinking it's kind of a chicken and the egg thing, marijuana. You wonder if they took the marijuana and brought on the psychosis or they got the psychosis. So they took the marijuana to cope
with their symptoms. I don't know. It's a tough one, but, yeah, definitely complicates everything. That's a good way to say it.
My name is Faydra Aldridge . Welcome to Look Again. Mental Illness Re-examined, a podcast brought to you by the BC Schizophrenia Society, otherwise known as BCSS, as well as our partner organizations. Today on the show, we're talking about weed, weed, marijuana, pot, lots of terms... there's an idea out there right now in society at large, which I'm sure we've all heard of, that cannabis is a harmless drug. It appears in nature. It's fine for us. Some people even use it to
self medicate. But for those with a predisposition for serious mental illness, such as schizophrenia, science now tells us that it's not so cut and dry. So how do we as a society grapple with this knowledge in a time of greater legalization? And how can cannabis be both helpful and dangerous to people with mental illness? Today on the show, we're going to find out. Today, we have the great honor of speaking with Dr. Nick Mathew, he has a very long title, but here's
just a little bit about him. Dr. Mathew completed an addiction psychiatry fellowship at Yale University and a forensic psychiatry fellowship at the University of British Columbia. He is board certified in addiction, psychiatry, addiction medicine and forensic psychiatry. He's a clinical associate professor at UBC and he's currently serving as the medical director of Complex Mental Health and Substance Use Services at the Provincial Health Services Authority. That's quite
a mouthful. We are so honored to have you. You're joining us from your home in Vancouver, B.C. And we understand your kids are playing in the background. So we might hear a little bit of noise from them. Thanks for being a multitasking dad and for joining us today. Welcome to the show.
Thanks for having me.
So, let's get right into it. Cannabis. We talk about it. We smell it. It's everywhere. And there's even some people that are saying now that it's being used as a miracle drug, it's helped them immensely and it's actually good for you and perhaps even a substitute for medication. So I'd love to get your perspective and your thoughts on this. Can cannabis be useful as a medication?
We should think of cannabis as a drug. Is cannabis a medicine? Well, it is. I mean there is a lot of good uses for cannabis and cannabinoids, but we have to get an idea of the effect size of these things, and are there other alternatives that are better? So if we're looking at mental health. They've looked at things like depression, PTSD, anxiety, psychosis, Tourette's, and they really haven't found good outcomes using THC for any of those things
with anxiety. It's pretty non-specific. So if we drill down to the positive studies for cannabis, the things that it's been used for is one, performance anxiety. The second thing is using CBD for the treatment of anxiety caused by THC. So we really have to drill down into the terms when people say this is good for. hat exactly do you mean? They have used it for psychosis and what they found is with THC, you can actually worsen the symptoms of psychosis.
So, Dr. Mathew, you talked about CBD and THC. You touched on it. But I would love to hear, number one, what is CBD and THC? If you could just give us a little elevator pitch. And number two, what is the connection between THC and severe psychosis or severe mental illness such as schizophrenia?
So the more psychoactive compound within the cannabis plant is THC. And so this is the compound that's going to cause the intoxicating effects of cannabis. The opposite compound would be CBD, which helps attenuate some of the psychoactive effects of THC over time. So over time, plants have been bred with
higher amounts of THC and lower amounts of CBD. So for people who have severe mental illness, the higher potency plants with the higher THC and lower CBD are more likely to cause negative mental health issues in those patients.
I'd like to delve into the connection with mental illness. I think it's so valuable to hear from experts such as yourself with so much knowledge in this area, to really dig into the link -- or the possible links -- between a drug like cannabis and serious mental illnesses such as schizophrenia.
A lot of times when people have severe mental illness, schizophrenia, bipolar depression, it tends to be that using cannabis will worsen the progression of these illnesses as far as if something's a risk factor or causative. So risk factors can be something that can predict something occurring, and it can also be causative. And those two aren't the same thing. So, for example, if you're looking at breast cancer, being not married predicts having breast cancer, but it's not cause of
it. The BRCA1 and BRCA2 genes are both predictive and causative of breast cancer. So when we look at the link between cannabis and schizophrenia, there's four main theories. The first theory is that it's a component cause. So what does that mean? That means that it's something that can cause schizophrenia but is not necessary for schizophrenia. The other link between schizophrenia and cannabis is that it can speed up the debut of symptoms
of people who would already get schizophrenia. Then the third thing is common genetic vulnerability so somebody who's going to get schizophrenia might already have a predilection to using cannabis. And then the fourth thing is that people might be self-medicating prodromal symptoms of schizophrenia. So we don't really know which of these or which combination of these causes or
the link between cannabis and schizophrenia are true. We're not seeing a flood of increased schizophrenia at a population level depending on cannabis use, and it doesn't seem to be related. And even in hospitals, it's not like our psychiatric wards are suddenly being flooded by people using cannabis, even though there's more cannabis in the population and there's a greater potency of cannabis. So my suspicion is, out of the four causes, I think it might be some combination of the last three.
That is a perfect tie-in because a mother that we spoke to, Dr. Matthew, told us that her son started self medicating when he first started to experience his symptoms of schizophrenia. So how common is it within your practice for people with schizophrenia or other serious mental illnesses to attempt to self medicate using cannabis or other drugs like cannabis?
I think concurrent disorders is more the rule rather than the exception. I mean, the people that we actually see in the psych emergency rooms, on the psychiatric wards, most of these people are using substances as well, and they are getting benefits from the substances, I mean, the self-perceived benefits. I'm not saying that they're good strategies as treatment overall
or long term, but there is an immediate benefit. So one thing that all these substances that people use have in common is that they increase dopamine.
And you've already given us some very interesting stats. But here's another one. This is from the BMC Medicine Journal. And the Journal states that up to 64 percent of individuals who have experienced a first episode of psychosis have used cannabis and 30 percent of these individuals have a cannabis use disorder. Those are some pretty high numbers. So what do you think we can do to get the message out there to the general population around these risks?
I think the thing with cannabis use is it is ubiquitous. I'm not sure if there's a way to prevent high schoolers from dabbling or trying cannabis, but I think some of the things to consider are the risk factors. So if people had a family history of psychosis, you might want to stay away from cannabis. So that might be a message to put out there.
You're listening to Look Again, Mental Illness Re-examined, a podcast brought to you by the BC Schizophrenia Society and B.C. Partner organizations. I'm your host, Faydra Aldridge. This podcast would not be possible without the support of the entire community. Thank you for caring about mental illness. Together, we truly can make a difference. [PROMO INSERTED] Welcome back to Look Again, Mental Illness Re-examined. I'm Faydra. Thanks for sticking with us. And here's where we left off.
This is just so fascinating and you've been able to provide us with so much valuable information. So now I'd like to share some thoughts from one of our panelists. We talked to some people on Look Again. And here's a clip from a young man with schizophrenia. So listen, because I'd love to get your thoughts on what this young man has to say.
I started smoking weed when I was like 16, and at first, it was just like once a month or once every three months. But once I got to university, I started smoking like every day, like when I got up in the morning to like all the time. And I -- up until the point I got arrested -- I was pretty much smoking weed the whole time. But yeah, I used to, my kind of tongue-in-cheek joke was "I'm not addicted,
I just can't eat or sleep without it." It did make me paranoid, definitely, but the time when I first had delusions was when I took two hits of acid, two grams of shrooms, and yeah, I started, that's when I started thinking undercover cops were following me. So weed definitely didn't help. Once I got arrested, I took a six and a half year break from weed, but then just recently, before I went to the psych ward, when I start hearing voices again and stuff, I did smoke it. And it was,
I was told it was a really, really, weak. It was supposed to be really, really weak. But I did I definitely did feel high from it. And yeah, I mean, is was a culmination of a lot of things that made my auditory hallucinations come back. But that was probably one of the big, one of the big reasons. And I regret doing that. Yeah, I think there's there's definitely a link between resurgence of my mental health symptoms and smoking weed. There's a link. There's a link.
So, Dr. Mathew, that was obviously one young man's perspective and his last quote there said, "There's a definite link" between mental health issues and cannabis use. What are your thoughts on that?
I would definitely agree with him. I definitely believe that there is a link between cannabis use and mental illness. This might have been a speed up of the debut of mental health symptoms, and it seemed to be linked. But one thing with substance-induced psychosis is that it's a neurotoxic event. So the general pattern that you tend to see is people use substances and they don't really have any kind
of issue with them. And then when we relate it to psychosis, someone might start getting some minor psychotic symptoms during intoxication. And then these symptoms become more severe, then these symptoms last to the withdrawal phase than they last longer and longer over a period of time. And it seems like that's what's happened with this gentleman. And that is what
I tend to see. If you do have a severe mental illness such as schizophrenia or bipolar or depression, you might want to stay away from cannabis because it hasn't been shown to benefit these syndromes. There's some nuance in there with CBT, with high doses, it can help attenuate some positive symptoms of schizophrenia, but people tend to use
cannabis as a recreational drug. And that's another thing to consider with this person was that you saw the development of a cannabis use disorder long before they had a psychosis. I mean, this was affecting his ability to function and continue to use, despite these negative consequences.
So as we talked about, Dr. Mathew, schizophrenia is a disorder that usually affects people in their late teens or early adulthood. And we've mentioned that, of course, this is also a time when many young people are starting to experiment with drugs. So according to the BC Early Psychosis Intervention Program, studies have shown that heavy use of cannabis increases the risk of developing schizophrenia -- ready for this -- two
to four times. But as we've talked about, the vast majority of users never end up developing psychosis and never end up developing schizophrenia. So how do we explain this?
Some years ago, there was a highly touted study where they showed that there was an eight-point drop in IQ for kids who started using cannabis, and it was really interesting how that whole thing rolled out, because after that study was published, there were letters published, the editors saying, well, maybe this is associated and not causative. And so the same author actually came up with a study later with twins. And what they showed was that they had twins, one
who would use cannabis, one who wouldn't. And they started at the age of 13 and they followed them over to the second study was into their 20s. And what they found was the drop in IQ actually occurred with both twins and it wasn't actually increased. So maybe there's a fundamental difference in kids who are able to use cannabis at the age of 13, then ones that aren't. There's risk factors that can help predict something that will occur,
but it doesn't mean they're causative. And I think that's what might be going on with the two-point four times, that is, that it might be an associated risk, but not a causative risk. Does that make sense?
Yeah, because I could see how people would argue that people would say, OK, you have all these stats, the stat that we talked about before, you know, up to 64 percent of individuals have experienced a first episode of psychosis, have used cannabis or the stat we just talked about. I can see people saying, so there's these high numbers. But yet schizophrenia is in quotations, "only" one out of one hundred people. So I could see people using that as an argument. So that's why I wanted to get
into it a little bit more. If people are saying, OK, you're showing me all these stats, but how does this translate into reality?
My opinion is that I'm not sure if cannabis is a component cause of schizophrenia. I'm not sure if you can take someone who would never develop schizophrenia, give them cannabis and cause schizophrenia in somebody. And I think we're seeing that at a population level. We're not seeing our hospital beds flooded with people with schizophrenia. The cannabis now
is more potent than it's ever been. The rates of cannabis use are higher than it is unusual for someone to graduate high school and not to have tried cannabis. Seventy percent of people who graduate high school have tried cannabis. So the number of people who have first episode psychosis, sixty four percent, is actually less than the population that's tried cannabis.
Wow. That's really fascinating, Dr. Mathew. So if I hear you correctly, what you're saying is that cannabis use on its own doesn't necessarily cause schizophrenia. But I'm also hearing you say that if you have a combination of other factors like genetic history, the presence of high THC levels, smoking pot at a young age, then you can put yourself at greater risk for the onset of mental illness. You're obviously a father, Dr. Mathew. I can still hear your
little one playing in the background. So what message would you, as a father, give your own child around cannabis use?
First, I would ask them to delay this. Or if you have to try now, please, one, get it from a safe source. And I think some of the things that we talked about earlier... if they could delay it, if they could use less, if they can use less potent versions, because I think it's very hard to get kids to stop trying these things. I mean, I think most kids are going to try things like alcohol. They're going to try things like cannabis. So if they're going to do it, do it in the safest possible manner.
Of course, the best outcome is if they didn't try it, I'm not sure if that's realistic.
So, as you said, 70 percent of youth are going to try most likely to try cannabis. So if somebody does start using and does start to experience psychosis in some form, what should they do?
So one is to get help early. So with your supports, try to see a physician and try to get a referral to a psychiatrist as early as possible. If you start developing those symptoms, after getting help, you also need to abstain from substance use. It's something that's not good for your body and it will only worsen over time.
I hear from even friends, colleagues, it's natural. Cannabis is everywhere. It's been around forever. It's a plant. It's a natural product. Why shouldn't I use it? It's better for me than alcohol. What's your response to that?
I mean, I think the fact is that they have a lot of valid points. And the way I would liken it is to something like alcohol. So most people in the population drink alcohol. In the same way, a lot of people use cannabis and it's the minority that have issues with it. And so if you start developing a substance use disorder, you start developing mental health symptoms, then it's not for you.
This has been such an informative conversation and a very, very important topic. The fact is that, as you said, cannabis is everywhere right now and there's so much emphasis on the legalization of it. And I'm just thrilled that we can now start to really focus on the health and possible health implications of cannabis. So thank you so much for joining me today, Dr. Mathew. And we look forward to speaking with you again.
Thank you for having me.
And now it's time to thank my incredible guest today on Look Again, Mental Illness Re-examined. And I want to thank you for listening. Your support means absolutely everything. Mental illness literacy is so important. It's important to you, to me and to us as an entire society. We have to talk about this. And together, I know we can do a better job of taking action. Talk to you soon.
This podcast is brought to you by the BC Schizophrenia Society and the B.C. Partners for Mental Health and Substance Use Information, where a group of non-profit agencies providing good quality information to help individuals and families maintain or improve their mental well-being. The B.C. Partners Members are Anxiety. Canada, BC Schizophrenia Society, Canadian Institute for Substance Use Research. Canadian
Mental Health Associations, B.C. Division, Family Smart, Jessie's Legacy, the North Shore Family Services Program, and Mood Disorders Association of B.C., a branch of Lookout Housing and Health Society. The B.C. partners are funded and stewarded by B.C. Mental Health and Substance Use Services, an agency of the Provincial Health Services Authority. For more information, visit heretohelp.bc.ca