What to know about cannabis-induced psychosis

Evidence is mounting that cannabis use can trigger first episode psychosis, particularly among young people. On this episode of the CMAJ Podcast, hosts Dr. Mojola Omole and Dr. Blair Bigham speak with researchers and a patient with lived experience about what the data show, who is most at risk, and how clinicians should respond.

Bailey Peterson, a 26-year-old student from Mississauga, Ontario, describes how her cannabis consumption progressed from casual use to daily, all-day use of high-potency products. She recounts her experience with psychosis, the challenges of her hospitalization, and what she wishes she and her clinicians had known earlier.

Sophie Li, a fourth-year medical student at the University of Ottawa and an author of the CMAJ article Cannabis and psychosis, explains how rates of schizophrenia associated with cannabis use disorder have risen sharply in recent years and notes that young men in their late teens and early 20s are most at risk. For women, the highest risk tends to occur later, in their late 20s and 30s. Dr. Marco Solmi, psychiatrist and medical director of On Track: The Champlain First Episode Psychosis Program, reviews the evidence supporting a causal link between cannabis and psychosis and discusses how clinicians can distinguish cannabis-induced psychosis from schizophrenia, as well as approaches to treatment and patient education.

For physicians, the takeaway is clear: cannabis use—particularly before age 25—carries worrisome psychiatric risks, and psychosis can occur even without very high levels of consumption. Detailed cannabis histories, psychoeducation, and early counseling should be part of routine care for patients at risk of psychosis.

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Transcript

Dr. Blair Bigham

I'm Blair Bigham.

Dr. Mojola Omole

 I'm Mojola Omole, and this is the CMAJ podcast.

Dr. Blair Bigham

Jola, today we are talking about cannabis use and its association with psychosis. And this is something that, I mean, I see this in the emergency department a lot. We see a lot of people who have psychosis, a lot of people who use cannabis.

Sometimes that Venn diagram comes together. But I don't always know, like, how much of this is the cannabis versus how much is cannabis sort of self-medicating.

Dr. Mojola Omole

Exactly. And so this is really interesting to me that we're talking more about it and then juxtapose that with how readily available, and to be honest, normalized, using cannabis products are, without really thinking of... 

Dr. Blair Bigham

It is normalized.

Dr. Mojola Omole

Without thinking about, like, what's in this? Yes, it comes from the Canadian government. But do we know the potency of it?

Do we know the effect on people? And then putting that together with the increase in the use of cannabis and what can happen with psychosis, it's really scary, especially for anyone who's taking care of that vulnerable age population.

Dr. Blair Bigham

Totally. So it's legal, it's accessible. I mean, there's more pot shops and coffee shops in my neighborhood.

And also cannabis is becoming increasingly potent. The percentage of active THC is on the rise as well. So all of this is sort of...

Dr. Mojola Omole

Sorry, I also think the route of usage is also different, you know, before people used to just, you know, roll a joint and smoke, but now there's things called shatter, there's vaping it, which we can all just imagine you're getting such a more potent effect of it.

Dr. Blair Bigham

And also edibles, you can get it as a soda. It's just there's so many different ways to consume it now. And this risk of psychosis sort of, it seems to have fallen by the wayside.

It's not part of the conversation. So we're going to dig into a CMAJ article called “Five things to know about cannabis and psychosis.”

Dr. Mojola Omole

We're going to speak to two authors of the CMAJ article, Dr. Marco Solmi and Sophie Li, a fourth year medical student.

Dr. Blair Bigham

But first, we're going to hear from someone who's experienced cannabis-induced psychosis. Bailey Peterson is a 26-year-old student in Mississauga, Ontario. Her story comes up next.

Bailey Peterson

Hi, I'm Bailey Peterson. I'm a psychology student in Mississauga. I'm currently working in the field of mental health and addictions.

I'm really passionate about harm reduction and suicide prevention.

Dr. Blair Bigham

Bailey, when did you first begin using cannabis?

Bailey Peterson

So I began using cannabis around the end of 2019, just super recreationally. It was like the first time I ever tried it. And yeah, it was just with a group of friends who were casual smokers.

And I didn't really get into it until around the COVID pandemic.

Dr. Blair Bigham

How much cannabis were you using at the beginning?

Bailey Peterson

At the beginning of my journey with cannabis, I was only smoking about one joint a week. And that's just how it began, was super casual, super recreational. And then it only increased from there.

Dr. Blair Bigham

Tell me about the increase. Why did that happen?

Bailey Peterson

So the increase in my cannabis use was a lot of stuff going on in my personal life. So I turned to cannabis as, like, an escape, something I did by myself. It started becoming more of a personal thing than a social thing.

I was doing it individually by myself, smoking probably just one joint every day. And then at the peak of my use was really when I switched from like physically smoking cannabis to using a vape pen and using like the cannabis cartridges of THC. And that became like a drastic increase with the percentage of THC I was using and the frequency as well, because it was so accessible, so easy.

So I would just be smoking all day, every day. And because you could use that indoors, there wasn't a smell, things like that. So when the ease of access opened up, that's when I was using all the time.

Dr. Blair Bigham

And then at some point you began experiencing psychosis. What were the first signs?

Bailey Peterson

So the first signs of my psychosis, I didn't notice myself. It was others around me who had to warn me about it. It was like a gradual descent with mood changes.

So I was a lot more, kind of, volatile, quick to anger. I was not myself. People would describe that I was, yeah, it felt like I was really somebody else.

The only symptoms that were really concerning and encouraged me to get help was when I stopped sleeping for a couple of days. So that's when, like, the psychosis truly began. Like, it was a slow descent.

And then I knew I was going into psychosis, like something very serious and different was happening when I went a couple of days without sleeping. And I felt like I didn't need to eat as well. And yeah, it was just a lot of different delusions, conspiracies and a disconnect from reality that set in.

Dr. Blair Bigham

And then one day you ended up in an emergency department. Tell me about that day.

Bailey Peterson

Yes, so that followed up with, that was following my days of no sleep. Like it was after the first day of not sleeping and feeling like I just had infinite energy and didn't need to sleep or eat. And I just felt sustained by just my own energy.

I was writing tons and tons, like filling books worth of like, just very scary kind of connections that I was making that now looking back on do not make sense at all. But at the time they were very, very clear and vivid to me. That was when my parents began to get really concerned and they were hoping to get me into a hospital.

I really did refuse care at that time. And yeah, they had to end up like getting one of my friends to come and help take me because I refused to go myself. I thought that, oh, I thought like it's like, of course, nobody understands.

These are messages that only I'm receiving right now. There's a, this is my purpose. Not everybody's going to be receiving it.

So, yeah, I was admitted to the hospital and I stayed there for approximately two and a half weeks.

Dr. Blair Bigham

When you were in hospital, do you remember the first time someone told you had psychosis that might be associated with cannabis?

Bailey Peterson

Well, actually, that was a really interesting piece of it is that nobody, like in the hospital, they did discuss that I was in psychosis, but the possibility of it being cannabis induced was not really discussed. I was misdiagnosed as having bipolar disorder when I was in the hospital, and it really took doctors afterwards and the early psychosis intervention program that I was discharged to to get that right and realize that, oh, it was not a result of an underlying condition. It was simply cannabis induced.

My parents, they had their suspicions. They genuinely understood it as a cannabis induced psychosis at that time. But it did take like I only had one psychiatrist in the hospital that I had access to, and that was their perception and their diagnosis of me.

But yeah, cannabis wasn't really the discussion at that time.

Dr. Blair Bigham

How long did it take before someone brought up cannabis as a potential cause?

Bailey Peterson

So it took being discharged from the hospital and having more in-depth conversations with early psychosis intervention staff at my outpatient care. That's when the doctors got more of a full perspective of my lifestyle at that time and how much cannabis I was using at that time.

Dr. Blair Bigham

And what was life like when you got home from hospital?

Bailey Peterson

So when I returned from hospital, I was still very like, in a concerning state. I was spending hours and hours a day, like, just writing like nonsense. I was burning vinyl records because I believed things were certain, things were evil.

Yeah, there were a lot of people I refused to see. I was scared of a lot of my family. I was unable to drive, unable to work.

And yeah, my sleep was really disrupted. So yeah, it wasn't, I would say that I'm still healing to this day. I wouldn't consider myself fully cured of my psychosis until about a couple of months ago.

The psychosis until about a couple of months ago.

Dr. Mojola Omole

When you were out of the hospital, did you have a psychiatrist that was following you? Anything?

Bailey Peterson

So when I was discharged from the hospital, there was a time period where I had nobody. I was on the wait list to get into the early psychosis intervention clinic. I'm located in Mississauga.

So it was the Peel region that was responsible for me. And yeah, so I was discharged to them. But there was definitely a gap where I didn't have anybody.

So I was looking for, to find my own therapist or something to bridge the gap. Yeah, but I didn't get care until I think it was about two months after my discharge from the hospital. And yeah, that was with early psychosis intervention team, where I had a psychiatrist and a nurse that were dedicated to my care.

And that's really when the discussion of it being cannabis induced was solidified.

Dr. Blair Bigham

Looking back on all of this, what's your reflection? What do you wish you had known before all of this went down?

Bailey Peterson

Well, I know that before all of this went down, I would have loved to talk to my doctor openly about my cannabis use and maybe get some feedback on some kind of harm reduction tips, like maybe going lower in the THC concentration, maybe not vaping. I would have loved to tell pre-psychosis me that just because vaping feels a lot safer and feels like you're doing something better than smoking a joint or something. I would encourage myself never to get into that because it was so convenient.

It was just way too easily accessible. Yeah, I would just encourage myself to stay away from vaping cannabis or like just educate myself about different THC concentrations, what I was putting in my body and maybe ask the opinions about people around me, like just for their honest opinions on my use. I would also, yeah, it comes with a lot of shame like afterwards, so I would maybe want to prevent that, like reminding myself that, oh, it could happen to anybody, even if there's people using a lot more cannabis than you.

I didn't know it was going to happen going into it. I blame myself a lot, I feel like, throughout the process because I thought, oh, well, this is like cannabis-induced. I chose to use cannabis.

I should have known something like this could happen. But yeah, I just really didn't think of it like that because I knew a lot of people who were using so much more than me and I wondered, why me? Why is it, like, why am I predisposed to this?

Like, how come it doesn't happen to everybody who uses more or the same amount as me? So yeah, I would just take away the shame and yeah, warn myself definitely against moving to vaping.

Dr. Blair Bigham

Are you still using cannabis today? 

Bailey Peterson

Nope, thank goodness.

I did, I've abstained from cannabis since I left the hospital. There's been times where it's been really difficult not to relapse. There's been times where I've went out, bought cannabis, intended to use it and then stopped myself.

But it's just the ease of access and like, when you're allowed to do anything in the world, but there's one thing that you know you shouldn't do, you might find yourself wanting to do that one thing. So yeah, I have a lot of empathy for people who do continue to use and try to moderate their cannabis use after psychosis. What really helped me as well, I know it's not like a doctor or a medical professional, but I had a peer support worker through the early psychosis intervention program.

And yeah, just hearing like a person who had lived experience and they could shed light on what that process is like, how it affected them, their journey. Like I was asking them, Oh, have you used since then? And they were explaining the different times they relapsed, the consequences of things.

It really helped because I know not everybody is super comfortable or confident in their relationship with their doctor and might not want to open up to them. But it felt like there was not much of a power imbalance and I was able to talk freely about my use. And I think that did a lot for my recovery.

So it would be awesome if practitioners and people in the mental health field could respond like that, like with their own experiences or maybe people they know.

Dr. Blair Bigham

You've been on a remarkable journey. Thank you for your bravery and for sharing your story with us today. 

Dr. Mojola Omole

Thank you.

Bailey Peterson

Oh, thank you so much. I really appreciate it. It took a lot to get to this point.

I did not anticipate even going back to school or being capable of holding a job again. When I was in the thick of my psychosis, I couldn't even imagine where I am today. So, yep, I'm feeling really good about my progress.

Dr. Mojola Omole:

Amazing

Dr. Blair Bigham

So great to chat with you. Thank you so much for joining us.

Dr. Mojola Omole

Take care Bailey

Dr. Mojola Omole

Sophie Li and Dr. Marco Solmi are co-authors on the article in the CMAJ titled, “Cannabis and psychosis”. Sophie Li is a fourth-year medical student at the University of Ottawa and the lead author on the article.

Dr. Marco Solmi is the medical director of On Track, the Champlain First Episode Psychosis Program. He's a psychiatrist and the director of research in the Department of Psychiatry at the University of Ottawa.

Sophie and Marco, thanks so much for joining us today. 

Dr. Marco Solmi

Our pleasure, I guess.

Dr. Mojola Omole

So what do we know about the incidence of cannabis-induced psychosis? And is it going up?

Sophie Li

Yeah, over the past 17 years, the new cases of schizophrenia that are associated with diagnosed cannabis use disorder, it's increased greatly from 1.6% in particular in 2006 to about 9.6% in 2022. But it didn't actually accelerate necessarily after the legalization of cannabis, but it has still been an increasing trend.

Dr. Mojola Omole

So Marco, how often do you see cannabis contributing to psychosis in your clinical practice?

Dr. Marco Solmi

That's the rule rather than the exception, to be honest. As a majority of people that access to our service, just to give you some context, our service is providing care, early intervention for psychosis for people from 16 to 35 years old. And we do see a large number of people that use cannabis or in whom cannabis has played a role.

It might have been the major role. It might have been a peripheral role, but it might have been the cause or just a contributing factor. But in the vast majority of people, there is cannabis use.

Dr. Blair Bigham

In your Five things to know article, you mentioned that the potency of THC has really skyrocketed just over 20 years, from 4% to 20%, and that's for dried cannabis. When somebody walks into a commercial dispensary and they're looking at their options or speaking to the person at the counter, at what point do you think that THC becomes high potency? Is there a percent that people should be on the lookout for?

Dr. Marco Solmi

I wouldn't be able to answer this question because if I were to answer this question, then automatically I would be indicating a safe threshold, right? So I wouldn't feel safe in telling you, well, below this threshold it's okay and above this threshold it's not okay.

Dr. Mojola Omole

And Marco, is it clear that if there's an increase in the potency, there's going to be an increase in the risk of cannabis-induced psychosis?

Dr. Marco Solmi

So that's the thing with this type of harm. So the association between cannabis and psychosis in general or schizophrenia more specifically, is very hard to prove from a causal standpoint. But there are, I would say, good reasons to believe that there is a causal association, that's an opinion that's not scientifically proven yet.

Let me elaborate a little bit more on this. Back in time, I think a few years ago, we published a huge evidence synthesis in the BMJ, which is one of the major medical journals. And we collected evidence from randomized control trials, observational studies as well, like some of those that we have published.

And there was evidence from both sources of evidence, from both study designs, that cannabis can actually increase the risk of psychotic symptoms. So this link is not only shown in cohort studies like the ones that we conduct, but also from randomized control trials, people that are exposed to THC specifically, not much to cannabidiol, which is another active principle of cannabis, but to THCs mainly. Those people do develop psychotic symptoms.

And there is also a third study design that is supposed to indicate causality, which is called the Mendelian randomization study. It's a sophisticated study design where you use essentially a proxy of the exposure to a potential cause to an outcome. And that proxy is what is called a genetic instrument.

So genetic alterations that are known to be associated with the cause. And what you do is you measure the association between that genetic instrument and the outcome itself. Those studies can infer causality free from environmental confounding factors, et cetera, et cetera.

And there are a number of those studies that indicate an association between cannabis and psychosis. So it's not only just one study, and we got it wrong. Maybe there's this huge confounding we couldn't control for.

There's more studies and from different study designs that are all converging and indicating that cannabis is associated with increased risk of schizophrenia.

Dr. Mojola Omole

Sophie, I just wanted to go just more in terms of who's at most risk of this in terms of cannabis-induced psychosis, according to the research.

Sophie Li

So according to the research as well, typically the population that is affected quite early on is young men. This usually happens between the ages of like their late teens to the early 20s. And that's when they're at that highest risk of unmasking the psychosis.

They're usually the largest population, but that doesn't mean that other people aren't subject to this as well. Like for younger women as well, typically the times when this really surfaces is also within the ages of your mid to late 20s, I believe going into your 30s. So it's a little bit different between women and men, but the most common population is younger men.

Again, it can still happen at many ages, but at least from what I've been seeing quite often is that many of these cases are young people. And again, this is just from what I've been seeing clinically rather than what I've been researching necessarily too. The research also does show that it's young men.

In terms of clinically, you can see people of many different ages. And typically I see it in young people perhaps because they're also a higher population of users too.

Dr. Blair Bigham

Sophie, you used the word unmasked. Marco, help me get this straight. Are we unmasking an underlying psychotic disease in people who, like, you use cannabis and your underlying condition comes out, or is the cannabis causing the underlying condition?

Dr. Marco Solmi

Blair, this is the question if I was able to answer, then we would probably have- 

Dr. Blair Bigham

We could all go home.

Dr. Marco Solmi

We will probably be able to prevent psychosis, which unfortunately is not the case yet. But I think, so psychosis in general is what we call a multifactorial disorder, meaning that there's not one cause, but it's the concomitant presence of different factors.

It could be some genetic predisposition. It could be a very stressful period. It could be pairing up problems around maybe during pregnancy or during the early stages of life, infections or even other issues or use of other drugs.

So it's not just one factor. It's a number of factors put together. I don't think cannabis alone can cause schizophrenia.

There needs to be some kind of predisposition, probably. It's also true that probably some people, and the other question is, why do people use cannabis? Some people use cannabis because it's just for fun.

Maybe the friends do it and then they want to give it a try as well, right? And there's some sort of peer pressure is there maybe, and then they happen to use cannabis and then things go wrong. Other people are actively looking for substances because maybe they don't have access to care or maybe they don't feel like going to a doctor would be helpful.

And so they try substances to address some needs that they might feel. Maybe they're experiencing anxiety. Maybe they're experiencing insomnia or maybe they feel they're particularly stressed out.

And then they think about trying cannabis because maybe they heard it somewhere. Maybe they read it somewhere, right? And then they think that trying cannabis might be helpful.

And so then they start using it and then things can go wrong because of that. So yes, probably some people would have developed schizophrenia anyways. Some people, even without cannabis, some people might have developed schizophrenia though, maybe later in life.

Or some people might have never developed schizophrenia without using cannabis. It's really difficult to know though. And the problem is that we don't know who is going to have such a bad reaction to cannabis leading to development of psychosis.

That's the problem. There are some things that we know but many other things we don't know. So some things that we know is that using cannabis before age 25 is a very bad idea because the brain is still developing and over two thirds of people that develop mental illness, they develop before age 25.

So that is really the vulnerable period. That's the time we know where you don't want to gamble with your brain. But unfortunately, that's the time when people start using substances as well, right?

Dr. Blair Bigham

We heard from a guest just a few minutes ago named Bailey, who had experienced cannabis-induced psychosis and was hospitalized. But no one mentioned cannabis to her during her two weeks in hospital. She found out later.

Are there any distinguishing features between cannabis-induced psychosis versus other causes of psychosis?

Dr. Marco Solmi

Cannabis-induced psychosis can look very similar to schizophrenia. OK, so there are some symptoms that are very similar to those that you have in schizophrenia even without substance involvement. However, the time course and the timing and how quickly the symptoms have onset and maybe the absence of what we call prodromal symptoms before the full-blown episode are some key factors that raise the suspect that there might be some substances involved.

OK, so for instance, if somebody was working full-time, maybe also going to school, good grades, having a fulfilling social life and been doing very well and then all of a sudden, after a party, then they have to go to the emergency department and they're having hallucinations and paranoia and you name it. And of course, the rate of the suspect that is some substance of some kind involved is very high.

Dr. Mojola Omole

And how long does cannabis-induced psychosis typically last, Sophie?

Sophie Li

So typically it's not the same for everyone. So for some cases, it does generally resolve faster than what people would say like a primary psychotic disorder. So sometimes it can resolve within 24 hours with just abstinence or it can go up to like one to two weeks, but that's usually the maximum.

And then it depends on as well if they're just doing abstinence, if they're getting treatment faster with antipsychotics, for example. But this typically, again, as Dr. Solmi had mentioned, resolves faster than these primary psychotic disorders like schizophrenia.

Dr. Mojola Omole

And like in terms of treating cannabis-induced psychosis, is it always using antipsychotics or can some of it just be, as you said, abstinence?

Sophie Li

So I guess the way that you can look at treatment and how it goes is that there's many different steps. So one of them is harm reduction as well. So to decrease the use of cannabis and there's  a Canadian low-risk guidelines as well for that.

However, when you present to the hospital and you have this happening, there's actually not very specific international guidelines on what to do. So sometimes it's treated like a psychotic episode and they prescribe antipsychotics that they feel that are the most helpful at that moment. And then they, of course, take away the offending agent.

And then in the future, they say not to use cannabis again. I would also want to pass this on to Dr. Solmi, since this is quite his expertise here.

Dr. Mojola Omole

I guess I was going to ask you, Marco, how often do patients respond to the treatment?

Dr. Marco Solmi

So it's absolutely a treatable condition. Psychotherapy is the main approach. Unfortunately, there's no pharmacological treatment with proven efficacy specifically for cannabis use disorder.

It's important to keep in mind that some people do use cannabis because again, as I said, maybe they're having issues with sleeping. Maybe they have anxiety. Maybe they have depression.

And so they think they're helping themselves with cannabis. So it's also important to screen for coexisting, of course, mental health conditions and treat those. And so maybe then fixing sleep, then people don't feel like they have to use cannabis anymore.

So that's also very important to mention. But the concept of cannabis induced psychosis is probably a little bit, it might even be overdiagnosed because if you think about it, like cannabis induced psychosis or in general substance induced psychosis is a psychotic episode that should theoretically resolve and self-resolve after the substance affecting the organism are cleared. So when you have to start using antipsychotics and then a person has to stay in the hospital for two weeks, three weeks, then I would argue that it's hardly substance induced psychosis, right?

Because maybe there might have been a trigger, but then something else occurred, right? So it's important to keep in mind that theoretically substance induced mental health condition, they should self-resolve once the substance is cleared. And so if longer term pharmacological treatment is needed, probably a transition already occurred to something else.

Dr. Mojola Omole

So how do you counsel families and patients about their increased risk of psychosis and about also if, about future cannabis use?

Dr. Marco Solmi

Yes. I mean, the key is education, education, education. We do a lot of psychoeducation at our clinic.

So we have weekly sessions that anybody can attend. We have our skilled staff showing the slides and explaining the risks, among other things, also the risks associated with cannabis. And those are interactive sessions.

Of course, families have a lot of questions. They make examples. And so we provide individual counseling and psychoeducation to each and every individual case.

What I tell my clients is that if they had a psychotic episode from cannabis or after using cannabis, or let's say cannabis did play a role in the onset of their condition, then what I tell them that they should consider themselves allergic to cannabis. And that is a concept that I would say resonates a lot with many of them. And the feedback I get is, oh, now I get it.

OK, I just don't, I just cannot touch it. And that's the message that I want to give to them. Of course, I tell them they're not really allergic, but I may use that as a metaphor if you want to be more effective in communicating the concept.

And I think that's well received.

Sophie Li

I know that a lot of things that I see as well, I think one of the first things I want to address is the lack of psychoeducation. So usually what's going on is that there's no labels on any of these, like it's not the same as cigarette packaging, for example. And like the general public doesn't always have this information available to them.

So what I'm seeing is that people are coming in with the first episode of psychosis from cannabis and then you tell them that it might be related to cannabis. And it becomes something that's so surprising to them because it's not anything that they've ever heard of before.

And this can be also according to other substances as well, but they had not thought in the past to even associate with cannabis. And when you go into these stores, there's no warning sign at all. You see these pretty packagings, it's as easy to buy as candy.

And so it's not that, and I know that the way that I saw the comments on some of the CBC, on the CBC TikTok for this as well, is that the way that people can react to this is, well, I've been smoking cannabis for this long. I've been, I've been doing fine. I haven't ever experienced psychosis.

And as Dr. Solmi mentioned as well, we don't know if there's like a definitive amount for each person and that some people have protective factors. Some people, they're more sensitive. Like you would say they're in that sense, not actually allergic, but their brains are more sensitized to this so that they're more likely to develop psychosis and then schizophrenia.

So again, I think there just needs to be knowledge that there, these things can be taken in moderation, but that when there is an excess, that there has to be these consequences that the public is aware of. This is what the whole purpose of the psychoeducation is for, because so many people are just taking this risk, using cannabis to, it's just marketed as kind of like a miracle sometimes for people or as something that's totally safe. And it's not, that's the thing, like these risks aren't broadcasted to the public.

And so when they're told these things, like that they could probably use it for sleep, that it might help with their anxiety, that in the long term, that these are things that actually are impacted by the cannabis as well and can be worsened with overall cannabis use over time. And there's, and I think the biggest worry is that there's no warnings about this, like in school, they don't do teaching about this. They don't have these signs in like on the packaging in the stores, they don't warn you.

And then the first time these people are, they're experiencing it for the first time and they hear about the consequences and are learning about it for the first time in the emergency department or after seeing a psychiatrist.

Dr. Mojola Omole

Great. Thank you so much. 

Dr. Blair Bigham

Thank you so much for joining.

Dr. Marco Solmi

Thank you. Thank you for having us. It's been a pleasure.

Dr. Mojola Omole

Sophie Li and Dr. Marco Solmi are co-authors of the article in CMAJ titled “Cannabis and psychosis.”

Dr. Blair Bigham

So Jola, my overall takeaway here is that this sounds pretty scary to me.

Dr. Mojola Omole

And I would say that even though we haven't really sorted out the whole, the correlation versus causation when it comes to cannabis and psychosis, there seems to be a pretty strong, they're going down the same path. And I think- 

Dr. Blair Bigham

The association seems strong.

Dr. Mojola Omole

Yes. And one thing that stood out from Bailey, first of all, she's absolutely courageous.

Dr. Blair Bigham

She was so brave to come on.

Dr. Mojola Omole

I think it's just even the fact that not enough awareness from the medical community about how much usage, ways of usage, how often people are using, that we're not necessarily investigating that. I can say, I take a history.

I'm like, do you smoke? Do you smoke cigarettes? Do you drink alcohol?

Do you smoke marijuana? How much do you smoke? But I'm not really like investigating deeply into that, right?

And so- 

Dr. Blair Bigham

Yeah. It's almost like we need a calculator for this, because it's easy to say how many cigarettes do you smoke a day, or you smoke one pack or half a pack, and then you just do some math, you get your pack years. But it's hard to actually know how much exposure to THC somebody has.

Dr. Mojola Omole

And maybe that just needs to be part of the routine things that we do. And if, and once we understand better, and we think someone could be at risk of psychosis, we can refer them to the appropriate services to help them and counsel them about their use.

Dr. Blair Bigham

But also the scary part that it's not necessarily that you're only going to get psychosis if you have very high THC consumption. It could be someone who smokes a moderate amount as well. It could be sort of that, it almost feels like it's a ticking time bomb, at least from what the literature seems to be saying that although there does seem to be a dose response, you don't have to have really high exposure in order to end up in the ER.

Dr. Mojola Omole

And I think especially for young kids in that period, before your brain developed, before the age of 25, the problem is how many of those young kids go to doctors? How many of them are actually seeing their family physicians? And so that's also a gap that we have in our healthcare system, in that this population that would benefit from those questions are not necessarily, A, maybe have a family physician, or B, have access to see their family, or go to their family physician.

Dr. Blair Bigham

Yeah, that lack of access plus our sort of more sophisticated understanding of risk may be all we need to sort of question the current regulatory structure around all this. That's it for this episode of the CMAJ Podcast. Please remember to subscribe to our podcast and like or share it wherever you can to help us get the message out.

The CMAJ Podcast is produced by PodCraft Productions in Ottawa. The Senior Editor of the podcast is Catherine Varner, also Deputy Editor at CMAJ. I'm Blair Bigham.

Dr. Mojola Omole

I'm Mojola Omole. Until next time, be well.