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Crystal methamphetamine use with Dr. David Castle



Dr. Gratzer interviewing Dr. David Castle


In this episode of Quick Takes, Dr. Gratzer sits down with Dr. David Castle to discuss the upwards trend in crystal methamphetamine use and what interventions are available to physicians.


You’ll learn a lot in this 28-minute episode, including:

  • why there's been that sharp rise in use here in Canada
  • its impact on emergency departments and on staff physical and mental health
  • steps to take when dealing with an agitated patient
  • medications that work in different scenarios
  • and the evidence for psychological and psychosocial interventions.



    Or     Download the transcript as a PDF

October 19, 2022

Crystal methamphetamine use with Dr. David Castle

[Musical intro]

When he's well, he's pleasant and funny and he always thanks me at the end of our sessions. He works full time as a dishwasher downtown, but when he uses crystal methamphetamine, goodness, he's a different person. He can be psychotic, agitated and aggressive. He's actually been charged recently with assaulting a hospital worker. Through this pandemic, we've seen more substance use and we've seen more crystal methamphetamine use.

David Gratzer: Welcome to Quick Takes. My name is Dr. David Gratzer. I'm a psychiatrist here at the Centre for Addiction and Mental Health and today we're joined by Dr. David Castle, who's also of CAMH, to talk about crystal methamphetamine. Dr. Castle is the Inaugural Scientific Director of the Centre for Complex Interventions here at CAMH. He's also a person who's had a big career before moving to Canada in Australia, where he's a full professor at the University of Melbourne. Dr. Castle has written much about substance and crystal methamphetamine. He's written much about much as it would turn out. He's authored more than 26 books and hundreds of papers. Dr. Castle, welcome to Quick Takes.

David Castle: Thanks so much, David. Great to be here.

David Gratzer: Now in Australia, there's been a lot of attention on crystal methamphetamine use in recent years. How come?

David Castle: Well, because it's a highly prevalent, highly available, highly pure and highly destructive. So we have really seen the impact of it big time on societies, especially rural societies interestingly, in Australia, where they've been just torn apart by crystal meth. But we've also, of course, in metropolitan centres seen the impact on emergency departments and psychiatric hospitals and on physical health. And of course, the ramifications of all of this for things like domestic violence, criminality. Real, real, real big problem.

David Gratzer: And a problem outside of hospitals, but also within hospitals. I understand many hospital workers have been injured as a result of crystal methamphetamine.

David Castle: Yeah, well, I know because we work in a psychiatric hospital. Unfortunately, aggression is part of our day to day. And what we have seen in Australia when we analysed this was that the majority of aggression towards staff, towards other patients and towards property was perpetrated by people on various drugs. Of course alcohol still plays a big part and we mustn't forget that. But crystal meth is associated with the level of aggression and aggressive behaviour, which is in my experience unprecedented. And I think your little encapsulation of your patient who was very pleasant and very nice and everything else that went intoxicated with this stuff, people become different. You don't recognise them because they're just so driven, so psychotic sometimes and so, so aggressive.

David Gratzer: How do you think crystal meth use is similar or different here in Canada compared to Australia?

David Castle: Well, I think one is the rates are lower still in Canada, although they are rising. The other thing which I think is different is in North America generally, and in Canada specifically, there's this massive opioid problem. Now that also pertains in Australia, but it's not as pervasive and we certainly, in Australia, didn't have the extent of deaths with fentanyl overdoses and so forth. So the opioid crisis, as it is called, has pervaded the scene, I think, for better or worse. But now what we're seeing in North America is that people are using more and more crystal meth on top of opioids. So you get a downer and then you’re using meth as an upper. And that's another difference in pattern from Australia, where it tends to be a sort of drug of use by itself.

So it's cheap, available, very pure. And also I think that the use of it has switched to some degree because it's very easily smoked. Some people inject, of course, but smoking is much more prevalent now.

David Gratzer: What trends have you seen here in Canada?

David Castle: Well, interestingly, as you know, because you're a co-author on a paper which is about to come out in the Canadian Journal of Psychiatry, we looked at the last seven years of trends at CAMH and it's a pretty dramatic increase from about 2% of contacts with emergency department, up to about 9 to 10%. And that's also reflected on the inpatient wards. So we're certainly seeing a rise here. Also with us, an increase in psychotic presentations with crystal meth, as well as an association with opioids.

David Gratzer: Why do you think there's been that sharp rise in use here in Canada?

David Castle: Crystal meth is a very easy drug to get addicted to. The chances of re-using after you've used once are very high because of a number of factors. One is it causes a very dramatic, profound increase in dopamine, which is the main reward chemical in the brain, also serotonin and adrenaline. The other thing is that if you take it and you have an amazing experience, which people think that they do, and then you don't take it, you can have a very nasty crash. And if you think about it, you've had a wonderful experience, you have a crash. What do you think? Well, why should I feel awful? I'll just take some of the same and it starts an up and down, up and down, up and down cycle. Now, I should say some people can use this in a somewhat more controlled manner so we can use and so forth. But the danger of getting addicted to it and using more and more and more for the same effects and more and more often is very, very real.

David Gratzer: Demographically speaking, who are we talking about as a potential user of crystal meth?

David Castle: So different groups who use some high, highly educated, high-earning people use it as a stimulant and on weekends. There's obviously use of it in some communities. Men who have sex with men for example, where it's largely used about the enhancement of the sexual experience. And then there are people who are more down the socio-cultural strata, if I can put it delicately. Partly because of crystal methamphetamine, often mixed with other drugs, of course. And they often develop a chronic medical and mental health syndrome, which looks actually a bit like chronic psychotic disorders like schizophrenia. So there's different groupings and people use in different ways. I think what you and I would tend to see at CAMH would be people in the latter group mostly, although sometimes we see people who come into the emergency department with acute sort of what we call a toxidrome. So they have a short lived 24-hour high and then they're relatively well afterwards, if they don't use again. If they repeatedly use they get accumulative problems. But the others who we see are people who have more enduring psychotic disorders, which can become pervasive and unrelenting and as I said, very like chronic schizophrenia. And associated with that are physical health problems, and those are myriad, as well as cognitive problems. So the drugs which really impact your brain are alcohol and crystal methamphetamine.

David Gratzer: What are some things we might see in an acute presentation here at CAMH or at an emergency department elsewhere?

David Castle: Often people who are so unwell and so agitated and so aggressive and brought in by police, it's often a highly disruptive experience for everybody and traumatic for everybody, including the patients themselves, their family and medical and other personnel. Often very dramatic, driven – the motor drive is something which is to be beholden too because it often also then becomes very readily sparked and channelled into aggressive behaviours. Some of the signs are things like grinding of the teeth and clenching of the jaw. The phenomena associated with psychosis are usually very uniform in the sense of grandiose beliefs, sometimes beliefs that you can fly or the standard manic type symptoms. So a cross section, it looks like a manic syndrome. Sometimes, and this is very important because it can be missed, sometimes people actually have a delirium associated with it that might be a direct effect of drugs, or it might be associated with other medical and other issues and/or other drugs which are used in the same process with the use of crystal methamphetamine. So being aware of that, being sure to check up on people's physical health and check just what their orientation and everything else is and taking care too. You're aware of other things which they might have taken, because sometimes you can be so focused on the crystal methamphetamine that you forget that they've actually had a whole lot of alcohol as well, and maybe just a whole lot of benzodiazepines which are going to suppress the respiratory system. All of these issues.

David Gratzer: Can you think of somebody's presentation that was particularly spectacular when you were working at St Vincent's?

David Castle: So St Vincent's in a city hospital and in Melbourne and we had a lot of presentations with this. Yes, I can remember one chap completely dismantling the seclusion room. The seclusion room wasn't very tall or not very high, and the patient was very high. So he managed to bash the entire ceiling in and was pretty close to getting out of the seclusion room. And he was very difficult because he was so aroused and so aggressive and smearing feces all over the seclusion room. It was a very difficult to actually go in there and control the situation. And obviously he was a danger to himself in that environment.

David Gratzer: Scary. What are some steps that one would take with management for a person this agitated?

David Castle: So in the acute phase, it really is a psychiatric and sometimes a medical emergency. You know, as I said, being aware of the medical problems, including cardiac problems, people can have acute several vascular events and there's acute cardiac events which can occur as well. So being aware of those. Also dehydration, etc. But, you know, you have to control the situation. The general rules would pertain in terms of trying to reassure the person that they're in a safe place, that it's important to control things for the safety of them and everyone around them. Try and talk calmly. Try and engage them as best you can. Sometimes that just doesn't work, unfortunately, and you'll end up restraining people, but sometimes that's all that is required. In terms of pharmacotherapy at St Vincent's, we developed an algorithm where we would always offer oral medication first. We tended to use olanzapine wafers because they're very easily dispersible and pretty safe. And also benzodiazepines. Just being aware they might have used benzos and or have quite a bit of tolerance for benzos, and there's addictive potential. But in the short term, I think it's quite reasonable and warranted.

We then found if oral medication is not going to work, intramuscular haloperidol, funnily enough, we ended up with. I know it's an old drug and I know that it can cause laryngeal and other dystonia which you need to be aware of and there was a lot of concern about its use in terms of QTc prolongation. But we found that actually it really takes the, it can really attenuate the drive so dopamine d2 receptor postsynaptic block it primarily but also has alpha receptor block. So it's helpful with those. So we ended up actually using, not haloperidol, droperidol actually more. Haloperidol is much the same but as I say, a little bit more sedating. So that's what we ended up with. If you only have haloperidol, then you can use that. Canada is slightly different I think because it has some other drugs, like loxapine, which we didn't have. But, you know, often you're lining up these patients, unfortunately, going for restraint, forced injections, and it's not pretty for anybody. And traumatic and people have post-traumatic memories from these things, including other patients and staff.

David Gratzer: How did things work out with that super big, super agitated patient at St Vincent's?

David Castle: Well, it's a bit like what you said, and I really like it because I think it's really important, and this can be very difficult, not to judge people as to who they are when they are acutely intoxicated with any substance. And that was the truth for this man. I actually got to know him very well and just to see him in the outpatient clinic. And he was a lovely, gentle giant. And, you know, we still had times when he would use and he would end up coming in. And that was increasingly less because we engaged him in really trying to bring to him the fact that the way he behaved during those episodes was not him. And actually he had a very lovely family who were very supportive. So bringing all of that in and marshalling all of that and dealing with his underlying psychotic disorder adequately, and here I'd advocate for long acting injectable medications. Common for us to use them in this context.

David Gratzer: Focus on meds then for a moment. So, you know, after that agitated, acute presentation, thinking in terms of substance use disorder and management, what are some suggestions you would make?

David Castle: Well, the most important thing to do, I think, is to engage the patient and the family, if possible, in a discussion about the whole thing and how destructive this drug is. Then looking at, we are very keen on understanding reasons for use. So we have a scale which we developed called the Reasons for Use Scale, which actually, instead of naming people and saying don't use, you actually say, why do you think you use? And sometimes it can be for very obvious reasons which you might be able to look at the factors which you might be able to address: psychosocial stress, depression, you know, these things which might be amenable to other interventions. Then assessing importantly whether there's an underlying psychotic illness. So, I always make this distinction between people who have that acute, abrupt toxidrome and then settle and don't have further episodes unless they use again. They are quite different from the people I described earlier who have rumbling ongoing psychosis, whether they're using or not. The latter group, unlike the former group, I think warrants ongoing pharmacotherapy, as I said long acting injectable. And there's certainly good evidence that Clozapine has a particular role with some of these individuals. Of course, there are all sorts of other issues about Clozapine because of its unique action it has reasonable evidence actually. As you can imagine, it's a very difficult area to do randomised controlled trials, but reasonable evidence, cumulative evidence, that Clozapine is a particularly useful role in this scenario.

David Gratzer: And thinking about the literature evidence for other classes of medications, antidepressants and the like.

David Castle: Well, just about everything has been tried and most have worked very well. Unfortunately, the one which does have some support in which I have some clinical experience with and use quite a lot in this context is mirtazapine. It's a sedative antidepressant, a bit unusual actually – a presynaptic alpha receptor blocker – but also has quite substantial histaminergic blockade. So it helps with both sleep and also appetite. A lot of people with chronic crystal methamphetamine use disorder don't eat at all and can become really quite malnourished. So it has those virtues. The trials are not that many, and most of them are amongst that particular subgroup, men who prefer sex with men, and in that context. But it does have some credibility there. And as I said, that's the one which I would tend to use. There are some interesting alternatives which have been looked at in terms of sort of substitution therapy including modafinil, although the outcomes were not brilliant. But now there's interest in lisdexamfetamine. Lisdexamfetamine has appeal because it stacks amphetamine with the Lys moiety attached. You have to actually take it orally and have that Lys moiety cleaved off before it becomes available. And it doesn't give the rush, which methamphetamine does so a much slower release. So there's a trial which I think is still underway or was just concluded in Sydney, in Australia, and I understand there's a trial about to get underway in Canada as well. So that would be interesting. The one caveat around that is that if you are using stimulants as a sort of substitution therapy and then on top of that the person is going to use straight crystal, you could have an accumulation of particular adverse events, including hypotensive events and other cardiac events.

David Gratzer: A lot of stimulant potentially. And pivoting for a moment in terms of psychological and psychosocial interventions, what's the evidence?

David Castle: So a psychological wraparound and the context and the containment and the rapport building and the respect for the individual is really key. You know, these people have a very bad time, often from services for obvious reasons and are really trying. And they are often people who have had trauma in their lives as well. So being able to engage them is critical. Contingency management has some support. I know it's not done very much in Canada. Not actually done very much in Australia either, but certainly in the States. Some studies support it and we are very interested now in acceptance commitment therapy. So we did a pilot study in Melbourne using some commitment therapy, group-based, and found there was a particular benefit for people with crystal methamphetamine use disorder and especially women. And I think one of the hooks for the women was that a lot of them had their kids removed from them because they were using and it was a value for them. So if you know acceptance commitment therapy, there's a lot about values and living a valued life. So for these women, I think some of it was about putting them into the therapy because their value is around getting their kids back and we're now looking at exploring that further.

David Gratzer: What would be the one thing you'd want clinicians to bear in mind in terms of treatment of crystal meth use disorder?

David Castle: I think the most important thing always with us is not to judge the person who is using. You know, these people can be, behaving horribly, really horribly when unwell, like the patient you described at the outset. You know, we've got to look at who they are underneath and really try to engage with that and keep our minds open to the humanity of what medicine is about.

David Gratzer: This literature has evolved quickly. What's something that's changed in your mind with regard to this substance and its use?

David Castle: The biggest change has been the shift from what used to be the most common use was tablets. So methamphetamine to crystal, crystal form and the smoking. So smoking obviously gets immediately pretty much into your brain. Intravenous, obviously, very quickly as well. But this is the main thing which we've seen the shift of has been to the crystal. And the crystal is very, very pure now. So you're getting a massive hit if you're smoking.

David Gratzer: You've done much research in this area. What are some research questions that that you can think about?

David Castle: Yeah, the research, we've looked specifically at longer term patterns and the propensity of some people to get an enduring ongoing psychosis. We've looked at, most importantly to me is treatment, and the treatment engagement. As I said earlier, very keen on the acceptance paradigm. I'm hoping to start a study soon on that. We're also interested in how we can deliver these things remotely as well as in person. So sort of COVID-proof. And also you can have reach to rural and remote areas which often bear the brunt of some of this. Certainly in Australia, as I said earlier, some sort of smaller remote communities have been torn apart by this drug. And the potential for medications. We shouldn't give up. I do hold out some hope that lisdexamfetamine will be helpful with the caveat, as I said before, about people who are still using street drugs on top of it, that it is potentially troublesome. And then there's something which I don't think we've got very well is about how you actually get to young people and try and turn them away from these drugs of abuse in the first place.

And, of course, they've been around forever in one shape or form. But societal pressures, especially now, with all the issues which are going on in the world, people are stressed. I think we need to look at how we can help them deal with all of those stresses and get more meaning and value back in their lives and divert them from initiation of these drugs. Because certainly with drugs like crystal methamphetamine you are hooked quickly, and you are hooked badly. It's not a benign drug which you can use once in a while for most people. Some people can, but that's just a few. And you and I, David, every day would see people who for whom they can't do that and it disrupts them. It's very bad for your physical health and it's a very bad for your relationships and it's very bad for your ability to integrate in society. And at the end of the day, we're social animals we need to build social supports for these people rather than dislocate them more from society by judgmental attitudes.

David Gratzer: Dr. David Castle, we appreciate your time and your insights, and we look forward to more of your papers in this area. Thank you today.

David Castle: Thank you so much for the opportunity.


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About our guest:

Dr. David Castle DAVID CASTLE, MB, ChB, MSc, DLSHT, GCUT, MD, FRCPsych, FRANZCP, is the Inaugural Scientific Director of the Centre for Complex Interventions (CCI) at the Centre for Addictions and Mental Health (CAMH), and Professor, Department of Psychiatry, The University of Toronto. He migrated from Australia where for 15 years he has been Professor of Psychiatry at St Vincent’s Hospital and the University of Melbourne. His clinical and research interests include schizophrenia and related disorders, and bipolar disorder. He has a longstanding interest in the impact of licit and illicit substances on the brain and body and is actively engaged in programmes addressing the physical health of the mentally ill and the mental health of the physically ill. He has received a number of commendations for his work, including the Senior Research Award from the Royal ANZ College of Psychiatrists (RANZCP) and a University of Melbourne Vice Chancellor’s Staff Engagement Award. In 2015 he was presented with the Ian Simpson Award by the RANZCP in recognition of outstanding contributions to clinical psychiatry as assessed through service to patients and the community. He has published extensively in prestigious journals and has produced 26 books, aimed at clinical, academic, and lay audiences.

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As heard on this episode:

Reasons for Use Scale developed at St Vincent’s Hospital, Australia


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