The International Cannabis Survey 2018 – Dr Musa Sami of KCL Replies

Dr Musa Sami with Peter Reynolds of CLEAR
Dr Musa Sami with Peter Reynolds of CLEAR
Dr Musa Sami with Peter Reynolds of CLEAR

Following the blog I posted on Sunday 18th March (The International Cannabis Survey 2018 – Kings College London), the researcher running the survey, Dr Musa Sami responded in the comments and I offered him the opportunity to explain in more detail:


From Dr Musa Sami
MRC Clinical Research Training Fellow

Hi Derek thank you very much for these comments. Like I had mentioned in my previous post we have spoken a couple of times and I have found it insightful. I understand some of your concerns about the survey and I will try and explain some of the issues below. Broadly there are two main themes that I have identified from your comments – one is that some of the questions are impossible to answer given your experience as a cannabis user (I can understand why this is the case) and the second is that you suspect we are fishing for mental health issues to stigmatise cannabis users (I can assure you we are not). I will answer in more depth below but let me explain a little about the survey first.

First I would like to encourage as many people as possible to fill out and complete the survey till the end – there is lots of space in the survey for feedback and your views about your personal experiences. It is open to all adults whatever your level of cannabis use. These are very useful and I want to assure you we look at every individual one and do not disregard any. When we collect the experience of 1000s of users the experiences speak for themselves. That said survey design is a complex art – it is important to get it right and I welcome your input (having said that I can’t change the currently launched survey at the moment).

Secondly let me clarify that has no ideological or political bent or axe to grind. What we are interested in is the different experiences that people have when they use cannabis, why they have those experiences and how that effects the decision to go on using or stopping. At the end of the day the data will speak for itself. I am not a policy-maker and have no aspirations as such. And this survey is not about political views, it is related to cannabis experiences, how they effect use and what might explain them.

Let me explain the history of the survey as it maybe useful. For most people cannabis use is a pleasurable activity (our survey clearly shows this). A much smaller proportion have a very different experience called ‘psychotic-like experiences’. When I set up the original survey we used what we felt was a fairly non-controversial instrument – called ‘The Cannabis Experiences Questionnaire’ to examine both types of experience and with a few modifications put it online. Like a lot of research, the response I had from the respondents was unexpectedly eye-opening.

The survey was very useful. We gained important new insights which should hopefully be coming out in the coming days. But I also realized we needed to improve the survey if we were going to run this again.

There were three things I got from the feedback: (1) we are asking about experiences in a stigmatizing way; (2) the nomenclature and classification we use as academics for cannabis is not helpful (particularly the use of the work ‘skunk’) and (3) it is difficult to pin down cannabis use over lifetime as clearly use and patterns of use vary over time.

To deal with (1): since then an updated experiences scale has come out to look at different experiences. I have taken consultation with cannabis activists amongst others and the feedback I have received is that the new scale appears more acceptable to users. I have incorporated these in my survey, and it seems these have been taken up relatively well.

To deal with (2) (the way we talk about types of cannabis) is a very big issue. I have lots of data about the feedback on this and am currently up to my elbows in it. One way we thought of dealing with this in the survey was to refer to strains directly in the survey and you will find them in the survey. We also try and ask each user to select one strain (preferably the one they have used the most) and ask the experiences they have using that particular strain. We ask about indica/sativa and ask if this makes a difference or if it’s the chemical composition which is important to the strain you use.

Issue (3) (talking about pattern of cannabis use over life course) is much more difficult to deal with. Like you have mentioned Derek people have a very rich and personal history with cannabis over their life and it is difficult to fit this into a ‘tick box approach’. Clearly you have a very varied experience over a long period, whereas others may have only used a few times over a brief period and the survey needs to encompass both. We need a survey which is able to capture across the variety of settings at comparable times. To do this, and to do it in a comparable way, I thought of asking at two periods – one is the use when you were using at your heaviest, and one is the use in the last six months when you were using. Obviously for those with much more complex histories such as Derek’s I accept that we are not going to be able to capture the whole history and we can only hope for an approximation of two time points which may be comparable. Still, I hope that is an advance over considering the whole period of use as the same as that of a single time point.

Now to deal with some of the points you had raised:

Ethnicity: we were trying to make a meaningful survey which may cross nationalities and this is actually a very difficult thing to do. ‘White British’ means something specific in the UK but is probably similar to ‘White Australian’ or “White American’ as a grouping – for example if we group Black African or South-Asian together then being White Caucasian is probably an overarching entity. I take your point that not all may know the term Caucasian but it maybe that those who cannot find their stated ethnicity will comment on it specifically in the ‘other column’. Of-course ‘White Swedish’ and ‘White Brazilian’ may mean very different things but we will be able to resolve this as we ask for country of origin and birth as well.

Mental Health and well-being: I understand the concern but the questions on mental health are not designed to go fishing for mental health issues and then retroactively fit that to cannabis use. What we actually want to know is whether having mental health issues change the experience you have with cannabis.

Similarly there are some questions to screen if the respondent is using cannabis in a harmful way (again this is from a standardized scale). This is not being used to advance any notion of cannabis related harms (we already know that most users do not abuse cannabis); it is designed to see if in that smaller group who meet that criteria, whether they are having different experiences to those who are using cannabis. This is important – for example I might hypothesize that pleasurable experiences are linked to non-harmful use, whereas psychotic-like experiences are linked to harmful use. This might mean that if you are having these psychotic-like experiences think about changing your pattern of use. This might be an important way for people to think about using safely. Or it may show exactly the opposite, or no association etc. The data will speak for itself.

We are not trying to stigmatize cannabis. I can understand the concern but this survey is not trying to show cannabis causes harm or mental health if anyone ticks yes to any of these questions. The survey is not designed to pick up on prevalence rates and would not be scientifically valid or have any serious clout even if I had tried to use it for that.

You also raise the question about the quit ladder: When we undertook our last survey I understood that cannabis use was not an all or nothing phenomenon. Use and also stopping-use is complex and I understand it can be difficult to pigeon-hole people into categories. However, having some kind of scale (which has been adapted from the previous scientific literature) is perhaps better than having a simple question of use/no-use

Finally you say:

The real pity is it doesn’t seem to consider reasons why people choose to use cannabis, it doesn’t look for the way cannabis integrates so well in social activities or anything like that, instead it just seems to think of cannabis use as some sort of drug use with no cultural motivation, so much for the aim of understanding what “people experience when using cannabis”.

Here I would say that there are questions on why people use, why they continue to use, why they change their pattern of use, why they may have stopped and why they choose the strain that they do.  These are mostly the free text non-tick box questions which I look at with colleagues expert in qualitative methods. I cannot understate the importance of these in our understanding as researchers. We really look in detail at each of the answers and it lead to the three main things I tried to change about the last survey as mentioned above.

What I have, however realized from the whole project is that we have to have a better understanding of the high we get when we use cannabis. We need to work together on this, knowing all the limitations in survey design and scientific method, to try and make sense of this wonderfully mysterious drug. At the end of the day the data will speak for itself and the best way to contribute is to take part in the research.

Musa Sami


Thank you Musa I appreciate you taking the time to respond like this. I suppose I find it depressing the there is a need to conduct research like this into something as widespread and commonplace as cannabis use. Enjoying cannabis has been pretty much normalised for a great number of years now and we really should know so much more about its use and the people who choose to use it than we obviously do. Prohibition is the reason for this lack of knowledge and until it ends this dangerous state of ignorance will continue.

Of course, if it is true that different strains of cannabis with different chemical profiles have different impacts on people’s health or well-being as some have claimed with the “reefer madness” and “skunk” claims, then a case for a properly legalised and regulated commercial trade becomes stronger.

The real key to ending the stranglehold of prohibition is by sharing knowledge of cannabis and anything that helps to do that is to be supported, so do please complete the survey, but also send comments to Musa at the e-mail address you’ll find at the end of the questionnaire.



UKCIA is a cannabis law reform site dedicated to ending the prohibition of cannabis. As an illegal drug, cannabis is not a controlled substance - it varies greatly in strength and purity, it's sold by unaccountable people from unknown venues with no over sight by the authorities. There is no recourse to the law for users and the most vulnerable are therefore placed at the greatest risk. There can be no measures such as age limits on sales and no way to properly monitor or study the trade, let alone introduce proper regulation. Cannabis must be legalised, as an illegal substance it is very dangerous to the users and society at large.

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