Feb 25th 2015 - Cannabis Update UK
'Jon Snow's negative experience on skunk is very understandable' Skunk stole Snow’s soul”, “Just say no, Snow” – these were just some of the headlines this week in response to Jon Snow’s blogpost and video recounting his experience of smoking ‘skunk’-type cannabis as part of a scientific study at University College London (UCL) which will be shown in a live TV programme – Drugs Live: Cannabis on Trial – on Channel 4 on March 3. We wanted to answer some of the questions raised by people about the trial as well as providing some of the wider context about this study, plus its aims and rationale. The study forms part of an ongoing research program into the effects of drugs on human cognition, emotion and behaviour at UCL’s Clinical Psychopharmacology Unit (CPU). Our cannabis research over the last six years has highlighted how different strains of cannabis have different effects. The cannabis plant contains around 100 unique ingredients called ‘cannabinoids’. Psychopharmacology The two most prominent of these are THC (tetrahydrocannabinol) and CBD (cannabidiol). THC is the stuff that makes you stoned. Our previous research, and that of a recent study by di Forti and colleagues, suggests that CBD may be a kind of antidote to some of the harmful effects of THC. It is clearly important to investigate this further given that cannabis was smoked by two million people in the UK last year and that around a third of 16-24 year olds have tried the drug. In the study which Jon snow and others took part, we are comparing the effects of two different types of cannabis. One type has high levels of THC but virtually no CBD and is often referred to as “skunk”. The other type, sometimes called hash, generally has a lower level of THC and substantial amounts of CBD. In the UK, 80% of the cannabis sold nowadays is skunk, making it hard for people to access cannabis with a THC-CBD balance. The increasing market dominance of skunk over the last decade has occurred alongside an increase in the numbers of people seeking treatment for cannabis addiction. About 10% of cannabis users now fit clinical criteria for addiction to the drug. We are concerned that skunk is far more addictive than other forms of cannabis and that it provokes greater paranoid episodes and and memory loss. Up until now, no one has ever compared the effects of hash or skunk in controlled scientific study. We designed our study so that the level of THC in the two types of cannabis was exactly the same – essentially this meant doubling the weight of hash relative to skunk. So the only difference in the two drugs was the CBD in hash. Under our Home Office licence, we imported both types of cannabis as medical cannabis from The Netherlands. We also imported the inactive placebo – which looked and smelled the same as the real cannabis – from the same medical supplier. Each of out 16 volunteers came to the laboratory on three separate days and inhaled the placebo, skunk and hash which had been evaporated into a balloon. Neither the researcher nor the participant knew which drug they would be receiving. This kind of design (placebo-controlled and double blind) is a gold standard in medical research, although we are aware that this context is not typical. We also conducted cannabis research in natural settings. The study was ethically approved and all volunteers gave informed consent which meant they could opt out of the study at any point for any reason. After inhaling a moderate amount of cannabis (about a third of a spliff) or placebo, volunteers carried out a range of tasks, some outside and some inside a brain scanner. These tasks were designed to explore potential positive as well as negative effects of the drugs. We used a technology known as functional Magnetic Resonance Imaging (fMRI); a way of looking at patterns of brain activity while subjects perform various tasks. This kind of technology is necessary in order to understand the effects of cannabis in the human brain, although a downside of this approach is that subjects have to lie very still in a narrow, noisy cylinder for about an hour. Some people find the scanner quite claustrophobic even when they haven’t taken a drug. Jon Snow’s very negative experience was therefore understandable even though it was uncommon. The vast majority of our volunteers completed the brain scanning session and all the other tests, and many of them said that they enjoyed the experience on cannabis more than on placebo. Jon himself carried out all the tasks outside the scanner and apologised profusely that he couldn’t tolerate being inside the scanner. As scientists we normally complete a study, analyse the data and then send the written report to an academic medical journal where it will be reviewed by other scientists before any decision is made about publication. The research paper is generally not accessible to the public, and is written using technical, scientific language. The results of this study will be submitted to journals in the same way. First, however, they will be revealed in a Channel 4 TV show (Drugs Live: The Cannabis Trial, 3 March 2015) for which a small number of volunteers were filmed. We feel this is important precisely because most cannabis users don’t read science journals and newspaper reporting of scientific findings on illicit drugs can be misleading. For several reasons, a few of our participants like Jon were known public figures. Firstly they were used to being filmed and were therefore able to consent to the filming in an ethical way. Second, they were mature individuals who had already achieved in life and whose reputation was unlikely to be tarnished. Most of our other volunteers were young and could be negatively affected in their future careers by appearing on television under the influence of cannabis. Third, Channel 4 largely funded the study (with DrugScience and the Beckley Foundation) and this clearly benefitted the science as well as television. Involving people in the public eye also helps the program reach a wide audience to engage a wider audience with the science of cannabis. We look forward to sharing our new findings with the public on March 3. We hope that the TV programme will be engaging and informative whether or not you’re a cannabis user. |
Cannabis update UK