Cannabis: pleasure, madness and medicine (Valerie Curran – 8 Dec 2015)

hello and welcome this launched our lecture very pleased to introduce current who today is going to talk she’s from the clinical psychopharmacology unit here at UCL and she’s gonna talk on the subject those things on the screen cannabis surya madness and medicine so over to you one moment thank you very much and thank you for coming there’s never been a more exciting time to be interested in cannabis it’s a completely different drug than it was 15 years ago so the the older people here will would not recognize it as being the same drug they might have come across at university it’s exciting because there’s global changes in legislation more states in america now have medical marijuana than don’t have Trudeau’s has been elected in to Canada as president with one of his band wagons being the legalization of cannabis changing in Europe and also it’s incredibly exciting that components of cannabis are now being developed as medicines for some disorders that we don’t have available treatments for so for all these reasons it’s it’s exciting I’m going to be giving you a rapid tour around pleasure and madness and medicine if you might think that we know roughly equal amounts about each of these but if we look at the scientific research we’ve been hardly any on pleasure it’s not been something that Research Council’s has funded it’s not something that politicians like to talk about it’s almost the elephant in the room when it comes to drugs the idea of pleasure we know a huge amount about what I called here madness it’s more to do with the negative mental health effects that can for some vulnerable people from using cannabis a huge amount of research has gone into this and increasingly now there’s research on cannabis medicines but not nearly as much as well need mental health effects but clearly you know cannabis is associated with pleasure Bob Marley would be very pleased now cuz this year the Rastafarians in Jamaica were given approval to grow as much of the weed as they liked so recognizing its spiritual context in in his home state and of course in places like Colorado Washington states you can go into these places that look like enormous sweet shops and you can buy all sorts of cannabis preparation chocolate truffles are apparently a favorite if you’re trying to find young kids finding what to get for granny for Christmas chocolate truffles laced with cannabis they’re a real favorite and you can even get lollipops so the commercialization of cannabis on the capitalist model that’s happening in some parts of America is very much based on the sort of pleasure idea and earlier this year we did a program channel thought for did a program about our research on cannabis and this was Neil who’s a very charming man who’d retired policemen he’d actually been an undercover drugs detective and this was about nine o’clock on a wet Wednesday morning and we just threw a vaporizer administered him some nicely balanced cannabis but much more focus has been on cannabis and madness basically Richard Nixon with the war who initiated the war on drugs pushed very much the line that all drugs were were evil if they weren’t tobacco or alcohol tobacco alcohol was fine everything else is no good and there we even films like reefer madness and the portrayal of madness being associated with cannabis so what did this madness nowadays would refer to mental health and there have really been two areas that people are focused in on the first is the risk of psychosis so that we now we know from epidemiological studies going way back that especially people

start smoking cannabis when they’re in 13 14 15 years of age in adolescence it increases their subsequent risk of psychosis it also it’s someone with a diagnosis of schizophrenia smokes cannabis they’re more likely to relapse so if they’re stabilized on their anti-psychotic medication that they’re functioning well if they then smoke cannabis they’re more likely to relax into an acute episode that proportionally affects a tiny percentage of people the vast majority of people who smoke cannabis don’t have psychosis and the majority of schizophrenics have never smoked cannabis a much bigger problem that we thinks increased over the recent years is addiction 9 percent of people who use cannabis will develop a dependence on the drug and all these factors depend on certain vulnerability issues because it’s only some people I mean we know that Prince Harry smoked cannabis and has no adverse effects David Cameron and smoke can refer cannabis and has quite a good job as things go it’s it’s not that it’s a direct consequence you have to be vulnerable and vulnerability to the negative effects of cannabis is conferred if the earlier age you start to use how much you use how regularly and they’re also environmental and genetic factors so we’ve known about these for a while but our research group we’re particularly interested in one thing that hadn’t had much research on it what about the type of cannabis you or cannabis in every language has lots and lots of different names in fact wherever I’ve given talks on cannabis I’ve always looked up the local terms for it and in every single country there’d been more words for cannabis than the Inuit or Eskimos houses snow but what does it actually mean all these all these different words well there are a lot of differences between different types of cannabis though cannabis the plant contains over a hundred unique ingredients that no other plant contains and we call these cannabinoids though there are over a hundred different cannabinoids but there are two that are really that really stand out the two most prominent one is THC tetrahydrocannabinol and that’s what makes people stoned the active ingredient that it’s what people want the effects are but there’s a very important other cannabinoid in cannabis and that’s called cannabidiol and these two things THC and CBD or a bit like yin and yang when they operate together it seems to be more harmonious and looking at them separately they have almost opposite effects so THC can make you anxious temporarily acutely and produce temporary psychotic like effects in healthy people and THC as you will know if you smoke the drug at the ball form it’s hugely impairs your memory and ability to learn or a couple of hours after you’ve smoked it CBD on the other hand reduces anxiety it calms you down it has and I’ll show you evidence of this in a minute antipsychotic effects like acts against schizophrenia type symptoms and there’s evidence that we and others have found that it actually can improve your mobility to remember and to learn and we in our first study with Celia Morgan who’s done most of the work with me we looked at people’s hair because in your hair is a record of your drug use so your hair grows about a centimeter a month and keeps in the follicle inside a record of all sorts of things to do with your diet and your drug use you can even go back to mummies in Egypt and find traces of cannabis in their hair it’s like a permanent record so if you take this lady perhaps here would have I could tell her drug use of the last three years she’s got quite long hair and so you can look at her and not only say fine cannabis but you can actually look at levels of THC and CBD so we did

this in this study I just put this lady up because some people have been known especially in the states where they fed up now using hair to drug test people some people actually shave their heads before they can get samples for the police so in this study we had groups of young people and we looked at their hair to see what the balance of THC in CBD was if there were any and we had 20 people only had THC in their hair 26 had CBD and THC said the balance and the majority 86 have neither and we used a measure of psychotic like experiences and compared those three groups and what we found was that unusual experiences which are akin to hallucinations and delusions in schizophrenia were markedly increased only in the people who had only THC in their hair so if they had no cannabis at all in her hair they were fine if they had THC only they had some positive psychotic like symptoms but if they had THC and CBD they were fine they were like people with no cannabis at all so it’s strongly suggested to us that CBD could protect people against the psychotic like effects of THC that was back in 2008 and it was really nice this year that a study came out really showing that this was definitely correct the study was by Martha 340 at the in City Psychiatry and what she did was she didn’t measure cannabis at all her biological measures but she did ask people with psychosis people with a diagnosis of schizophrenia and and matched controls and what she found was that those people who reported smoking skunk had three times the rate of psychosis compared to people who’ve never smoked cannabis and interestingly hash skunk is cannabis that has no CBD in it okay it’s just THC hash is traditionally balanced CBD and THC and hash did not increase the risk of psychosis so there’s a harm reduction message there and I think you’ll all get the F CBD can protect you against the psychotic like effects of THC could CBD then be used to to treat schizophrenia and this study was done by Marcus Levesque ER in Mannheim in Germany and what he did was he gave one group of schizophrenic CBD for 28 days in the other group Amy soul parade which is a traditional antipsychotic medication and this curve is just showing the reduction in psychotic like symptoms over the month and you see both treatments reduce symptoms in the same way in terms of side effects that one of the worst side effects of antes its the phrenic medication is people put on lots and lots of weight so you see here that myself arrived people put on about three and a half kilograms over the four weeks this didn’t happen with CBD all current antipsychotic drugs do this increasing weights it looks like it could be a promising treatment but I want to turn now to a much more common problem which is the problem of addiction there are about 180 million cannabis users in the world nine percent of those will be addicted and in Europe a recent survey shown that 1 percent of all adults and nearly 2% of 14 to 17 year-olds are addicted to cannabis and cannabis is now the second most common reason after heroin for young people going into drug treatment services there’s a very different picture if we’d looked at this 20 years ago it would not have been like this it’s a recent thing and this curve is showing you how much we’ve had an increase in Skunk that’s cannabis it doesn’t have any CBD in it community surveys and the lies for the amount of THC or CBD and you can see it’s really been shooting up since the early 2000s so what we’ve got is Skunk essentially

is getting rid of CBD and massively increasing the level of THC it’s a very different drug and if you look at the number of young people with addiction problems going into treatment over the roughly the same period the increase in Skunk cannabis has been paralleled by an increase in 14 to 17 year olds needing treatment for cannabis addiction we asked we had a large group of 420 cannabis users who 16 to 23 years of age group we work a lot with and we ask them what type of cannabis they preferred so they can either say no preference or preference for herb or resin which has lower THC and an increased CBD or preference for skunk which is the high THC but no CBD importantly and this is what we found these are all indexes of addiction so here it’s psychiatric classification DSM symptoms of cannabis dependence the skunk with no CBD in red hugely more addiction problems in skunk users craving for cannabis again massively increased in people who use skunk skunk and the time it takes to smoke an eight three point five grams of cannabis again people using skunk smoke their cannabis a lot faster than people who used other preparations and this is a survey done by Tom Freeman and Adam windsock it’s part of the global drug survey showing a very similar pattern it’s looking at the relationship between how dependent how addicted people were to the drug and what kind of preparation they were asked about and these are all people who are familiar with all three types and what they found was that it was only in Skunk users that there was a clear relationship between how often they used and how heavily addicted they were and one of the one of the effects of addiction to a substance whatever it might be is that that substance or pictures obvious or cues associated with it grab the person’s attention he’s one of the kind of brain mechanisms if you like or psychological mechanisms our drugs get to get to be so attention grabbing and we know that’s true of lots of drugs and the degree to which someone’s eyes move towards drug-related stimuli you can measure it with eye movements you can measure measure it with response times is related to the degree to which they crave the drug when they haven’t got it and the degree to which they are addicted and you can measure this with a simple task I imagine this is a laptop screen divided in two so on one side you have something that’s related to the drug in this case cannabis and on the other side something visually similar but has no relationship to the drug and it’s a very simple task you just ask the person to press an asterisk and either on the left or the right hand side as quickly as they can there nothing to do with the pictures so if you are actually looking at the drugs there you’d be very fast if you’re looking at the neutral stimulus you’d be much slower because your eyes have got to move across the screen okay and the same it’s all balanced for the other side and we looked at this in a group of 94 young cannabis users and we looked at it in terms of we we took a sample of the cannabis they had smoked and had it analyzed by the forensic science service know that we knew exactly what was in it in terms of the THC and CBD and both groups showed an attentional bias towards cannabis when they were sober but when they’d smoked their cannabis what we found it was only the people who had very low CBD that they were smoking skunk that had an attentional bias towards the drug those smoking hash or herbal with CBD in it actually CBD reversed the attentional bias it was almost like it was an antidote to the effects of THC so in a way Phoebe D

blocks that attentional bias and part of the brain that that attributes meaning to to information in the environment it’s called the brain salience network and it’s basically it guides people’s attention towards things that are important that matter to them so for example you might be a chocolate lover and your attention would go to the cake you might be an Arsenal supporter again the same salience network in the brain would would focus you towards Arsenal players or you might be a cannabis user and this would be more important for you and we looked at this in cannabis users where they came on separate weeks and they were either given skunk the pure THC which wasn’t balanced doesn’t have any CBD nurse or we gave them the balance the hash type treatment or we gave them the something that did nothing smelt the same as cannabis but didn’t have anything active in it people smoked tobacco or have anything unhealthy and we import the cannabis from the medicinal cannabis used in Holland because in the UK we don’t have any medicinal cannabis and what we found was aliens network connectivity between the different areas of the brain was much reduced if you had the skunk like preparation compared to the balanced one or placebo so again this is showing a disruption of connectivity in an important network in the brain that’s disrupted by THC as in skunk is restored by CBD CBD acting as the antidote to rebalance the network in the brain now interestingly we also in that study asked people to rate how stoned they were at various points after we give them the cannabis we gave them to lots cannabis to keep it going longer and what we found is very clear as you can see so the skunk is in red the tick the balance in green and placebo in the blue both types of cannabis make people equally stoned so in terms of how stoned you get which is the pleasure that people are looking for then both types of cannabis are the same it’s only the THC that matters the CBD doesn’t so there’s no real pleasure game smoking skunk compared to an eye can emit a balanced cannabis that has CBD in it well how does cannabis do all this to the brain well basically whether or not you’ve ever smoked cannabis we all have cannabis receptors in our brains now there are two types of cannabis receptors cb1 and cb2 vb1 are mainly in the brain and probably very important for a lot of the mental health issues cb2 receptors are mostly in our immune system and that’s why people are now looking at the relationship between these cb2 receptors in cancer where you’ve got diseases of the immune system now why would we have cannabis receptors why did God put cannabis that receptors there yep I mean not so that we could go and smoke cannabis we’ve got we’ve all got the receptors because there’s a natural chemical in the brain if you like the brains own cannabis the main one of these is called Ananda mite and it’s called Ananda might because I think the scientist who discovered it in Israel probably smoked cannabis himself because Ananda is Sanskrit for bliss and there’s another one that’s also in the brain a natural chemical that acts on all cannabis receptors which is called two AG one thing that we know CBD can do is it can boost an and amide by breaking down but by inhibiting the breakdown and it’s real take into into brain cells that might be a mechanism by which we’re finding these protective effects of CBD on THC and the brain zone cat I mean we’ve learnt so much about the brain from the drug Ashley it’s very interesting because by giving the drug from outside we can manipulate the brains own cannabis system and the

brains own cannabis system is critically important in times of brain development and an especially important one in adolescence when lots of changes are happening to the brain I mean adolescence is more about brain changes and is about hormonal changes it’s to think it was all hormones it’s not these these areas of the brain are the frontal prefrontal areas are developing rapidly in adolescence and we’ve come to understand a lot more about how that works and if you we think this is why because of the changes are happening if you smoke cannabis in adolescence it’s going to have a much more impactful effect than later on how does cannabis dependence affect the brains own natural cannabis system I mean in animals they they can look at the brain directly in humans we can only do brain imaging we can’t look directly in the same way but what we can do is take a do lumber pulp puncture so take three people spinal fluid and we can look at the chemicals in that and celia morgan and our group did this couple of years ago and what we found was that the level of the brains natural cannabis if you like an and amide was significantly decreased in those people who use cannabis heavily mostly daily okay i would and i want to come on to say a little bit about cannabis as a medicine it’s been used for thousands and thousands of years as a medicine especially in china and india and it was use regularly here before the war on drugs Queen Victoria famously used use tincture of cannabis for her period pains and throughout her childbearing time and if you think about it this plant that contains over a hundred unique ingredients is unique cannabinoids could potentially be a real treasure chest of new medicines but actually we’ve had cannabis medicines for quite a long time in the 1980s THC we gave it a name dronabinol was used for people who had nausea when they were undergoing cancer treatment it was used to stimulate appetite seen people with late stage aids and then in 2010 a spray called SAS effects which was an equal parts of THC and CBD became available for people with multiple cirrhosis to stop spasms which often prevented them sleeping and causing an awful lot of problems so these these cannabinoids are available as medicines yeah but not the drug not the plant okay in the UK it’s still Schedule one of the medicines act which means it has no recognized medical use at all so it’s very different from you know nowadays two-thirds of Americans can access medical marijuana Canadians can not several countries in Europe can Uruguay several South American countries can as well outside the UK these are the main uses for cannabis so that these are what you can get a doctor to prescribe you cannabis for in some countries so pain a muscle spasm in multiple sclerosis or spinal cord damage chronic neuropathic pain which is nerve cell pain which is very very difficult to treat otherwise we’ve talked about nausea and vomiting glaucoma that doesn’t respond to you to therapy sleep and anxiety are widely wide indications for medical marijuana and in California we’ve been working with one prescribing place there and we found that there are quite a few prescriptions for a completely new psychiatric disease we’ve never heard of before being in the medical books called writer’s block and at the moment there are current trials they’re really exciting going on across the world schizophrenia I’ve shown you one example of that lavaca study where CBD seems to be having a positive effect without having the horrible side effects of anti-psychotic medication diabetes is a big one that currently there are lots of trials going on and cancer I’ve

mentioned already in terms of those cb2 receptors being prompt prominent in the immune system childhood epilepsy there are currently five trials going on in the States and one in Edinburgh and in a way this was started by Charlotte Vicki her dad she had dravet syndrome it she’s a horrible childhood epilepsy syndrome where you can have 306 a week I mean it’s virtually uncontrollable and their life expectancy is not good well her father was obviously an intelligent man who’d been reading up on cannabinoids and he reasoned that CBD might actually help people with epilepsy and he persuaded a farmer to grow him cannabis where there was very little THC so the child wouldn’t get stoned but lots of CBD and in fact the growers decided to call the plant after Charlotte they called it Charlotte’s Web and it’s got about 18% of CBD in and at the last notification Charlotte was down to one a week around about 300 so people are very very excited again that the trials haven’t finished yet hopefully there’ll be data out towards the end of next year but there are a lot of people with epilepsy now who are doing everything they can to get hold of CBD because the early results are very exciting so to conclude cannabis addiction and psychosis risk are increased by the skunk high THC no CBD strains of cannabis CBD with jeesus th C’s effect on attentional bias and on the brain salience Network but it doesn’t affect how stoned you get so there’s no gain really you want your THC have it with CBD and that can be protective cannabis may cause long-term changes to the brains own cannabinoid system and especially probably so when it’s used in adolescents medicinal cannabis cannabinoids have huge potential there’s lots more of them have any mentioned too but they’re all be you know several others are being investigated what does it mean for policy well in a way if we could control the market you could promote higher CBD strains you could tell people how much THC was in what they’re getting at the moment you don’t really know what you’re getting unless you’re you have access to sort of ways of analyzing cannabis and we don’t have that unlike it in other countries such as the Netherlands but if you could control the market you could also inform people about individual vulnerability factors of what kind of potential damage you do if you had schizophrenia in the family if you had if you were under 18 years of age and it seems like the logical first step in the UK would be to take cannabis out of schedule 1 and allow medical use here so just for those doctors who fear that is appropriate and a lot of patients who feel that it’s their human right if cannabis controls their pain and nothing else does surely they should be allowed it they’re arguing and taking cannabis out of schedule one would also mean research was much easier I mean we could do research on cannabis because you have a home office license but that cost was quite a lot of money and we’re inspected and it’s not that easy whereas we can do anything on alcohol nobody cares so I think partly following the success of Trudeau in Canada who was recently elected the UK Liberal Party and now set up a working party on how they might legalize and go into the next election on that banner because it clearly works for some politicians and I with the House of Lords Committee on working party on drug reform the argument for making cannabis available as a medicine in this country is the first step but the government didn’t want to move on it though these are the wonderful team of people in teaming and you need more information this is our websites we are running a clinical trial at the moment for new treatment for cannabis addiction so if you do any up know anyone who’s affected you might mention it

thank you very much well by the way we have well timed we’ve got a certain amount of time for questions fascinating talk there’s obviously an awful lot of misinformation about is that thing that you wrote for the House of Lords available as a PDF on on the net ok I’m going to send it to my MP the I buy I’ve forgotten what it’s called but it’s it says it’s got no drug in it those seeds cannabis seeds to put in my muesli in the morning organic hemp yeah is that completely useless or is that good for us or is it rubbish no no no and have you done any assessments with older people people over 60 we haven’t actually done any direct work with people over actually some of the volunteers we had in studying at channel 4 filmed were over 60 including Jon Snow who had a very extreme reaction to it because they all say it’s in cannabis like it used to be it’s not it’s not stuff these two smokin actually he interviewed David Cameron just before the election and Cameron agreed all right yeah in Parliament recently they did debate cannabis being legalized but only about five people turned up so I don’t really think it was top of their list also the CBD oil medicinal oil I found that is available in this country a couple of vendors online and selling it so it seems to be legal but otherwise I wouldn’t be so yeah potentially not but they say that it’s very high CBD hemp oil and it’s calmed in a very kind of concentrated yeah now I’ve heard there are some people in Harley Street selling it to the people with use children have epilepsy but I think that it’s a bit dodgy is it do you guys know yeah the psychoactive substances bill is not very helpful for research I think there’s a question are you another question yeah how do you think the changing attitudes towards cannabis kind of more thinking about America because they all speak quite a lot than we are and paves the way for research on other psychedelics like psilocybin and DMT I think it can it can only be helpful I don’t think it could be detrimental but there’s certainly a sea change it’s partly linked to the fact that in the UK or in most of Europe the big pharmaceutical companies have left yeah there aren’t many of them left working in Europe they’ve gone to China and India where it’s cheaper and they can make more profit so what’s happened is that people are now looking at existing drugs there rather than hoping for new drugs to be developed a lot of mental health problems they’re having a look at the older drugs and it’s partly as a success of ketamine as an antidepressant but hey we’ve got another abused drug that is actually becoming a very positive medicine for people who have not responded to psychotherapy or any other antidepressant in their lives some of them are responding to ketamine so I think that’s really opened up people’s minds to maybe psilocybin and other potential so-called abuse drugs which you know have an action on serotonin in the brain like many of the prescribed drugs your brain doesn’t know that it doesn’t know what’s the difference between illegal drugs and illegal drug you know if it can do something positive thank you I must apologize to people on the left-hand side of the auditorium and because we really went at a time I do apologize and but it all reminds me to think that of a very much indeed for a very interesting