Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 420-439)


26 APRIL 2006

  Q420  Chairman: Would you support that, Colin?

  Professor Blakemore: Yes, and there are mechanisms for doing that. Calls for proposals highlighting areas of research of particular interest, or even specific calls for proposals with ring fenced funding, are both used by the research councils in areas of particular interest, whether policy interest or scientific interest.

  Q421  Mr Newmark: How well do you think the ACMD handled the two requests from the home secretary to look into the classification of cannabis? To your knowledge did the Council have and make proper use of the right expertise in arriving at that decision?

  Professor Strang: My understanding is that ACMD were asked to give a view on cannabis with a relatively short timescale in scientific terms. It is not an area that they had either chosen to or had paid specific attention to for something like twenty years. An initial opinion was given. Public opinion was shaped by that and policing action was shaped by that. Then some correction to that occurred. I am sorry to keep repeating myself, but what an exquisite experiment: you have a situation, you make those intriguing changes and then you even partially reverse it. I do not know—maybe you know—what impact that had on levels of use, levels of harm, levels of admission with related problems. How could you make the next decision without knowing the impact of the decisions you made recently had.

  Q422  Mr Newmark: Do you think it is in the correct category now?

  Professor Strang: I genuinely want to be helpful to the Committee but I am very much in what I call the Andy Hayman camp on this. Personally I do not think it is a hugely big issue. It obviously should be handled in different ways from other drugs like heroin, for example. In practice it is handled in a massively different way and it is the "in practice" which is far more interesting than what letter is attached to it.

  Mr Hayman: I presume you are talking about the first process, not the one that has recently been completed when you are talking about classification. The interesting nuance we have following that process is that it has gone into category C but if you look at all the rest from the policing powers perspective all the other drugs in C do not have the power of arrest that was retained for cannabis. So it has retained its unique position there and operationally that does present a very difficult challenge for policing. It was an interesting development in the classification of cannabis.

  Q423  Dr Iddon: Professor Blakemore, was the evidence about its causal or non-causal factor for mental illness available before all the media fuss arose after the re-classification?

  Professor Blakemore: It was not really, no. I mean there was some epidemiological evidence which was not very secure and I think it is fair to say that has grown over time and there is now a broad consensus that there is a causal relationship, although I would qualify that again by saying that the effects are very small. I think the figure is an 8% increase in the probability of schizophrenia as a result of substantial exposure to cannabis. The evidence has grown from that point.

  Q424  Dr Iddon: Of those people whose schizophrenia is triggered by cannabis do they eventually develop schizophrenia?

  Professor Blakemore: Not always. Amongst identical twins if one twin is schizophrenic the other one has a 50% chance of developing schizophrenia. So it is not inevitable that if you have the genes which seem to be associated with schizophrenia you will always progress to develop the disease. It depends on life events and cannabis appears to be a particularly potent life event in tipping people into that, into a psychotic episode.

  Professor Strang: There was a moderate body of evidence about a relationship with different types of mental illness and as Professor Blakemore is saying it is substantially stronger now than it was a few years ago, but we have known about cannabis induced psychosis since the 1840s so it is not that recent. What in a way has been disproportionate has been the sort of flip-flop nature of the public and the political view on it—that somehow it was completely safe or then completely harmful. I imagine all three of us would be trying to say that you have to find some understanding of it which is between those two extremes.

  Q425  Mr Newmark: What input did ACPO give to the most recent review of cannabis classification and what were the key factors influencing your position? I am particularly interested in your answer in the context of lessons learned from the Lambeth pilot assimilated into your policy making process.

  Mr Hayman: We are talking about the original process.

  Q426  Mr Newmark: Yes.

  Mr Hayman: I sat through every session with ACMD. It has to be said that the majority of the discussion was around the medical and scientific evidence that was available and I think that was highly appropriate. When it was appropriate for us to give input we did and that was around the impact on the community, discussions around crime and there were certainly discussions about drug driving. I think the work that was pioneered in Lambeth did not have a major feature in the considerations of ACMD because that was more about operational application on the street. What I think it did do was that it started to set a context from which maybe politically and maybe from the community that rose up in terms of a priority of consideration. We must not lose sight of course of the Foundation report which talked about the classification of cannabis and I think that was very influential. I think the two together set the context to politically consider it. In answer to your question as to whether it had much say in the consideration by ACMD it was minimal, if any.

  Q427  Dr Iddon: Professor Nutt and Professor Rawlins told this Committee that they thought drugs were classified according to the harm to society and harm to the individual fifty fifty. Why then are psilocin and psilocybin in Class A? I have never known anybody use them; I have never seen them on sale; there is no public fuss about them so why are they in Class A?

  Professor Blakemore: I think the short answer to that is because they were initially put in Class A and it is awfully difficult to get a drug out of one class into another, as we have seen with cannabis. This is one of the problems with the Act. When a new drug appears on the street and new concerns are raised about it the perfectly natural tendency is initially to classify it as being harmful and then to reassess and reconsider over time and have the opportunity to rethink how it should be classified. But with distinct categories of harm (as in the MDA system) it is difficult to move a drug from one category to another. The placing of the hallucinogens in category A was a reaction to the concerns about drugs which were newly available on the street in the 1960s and 1970s with not much scientific evidence about their actions and certainly their long term consequences. You are quite right, the situation now is that they are not widely used. The evidence of toxicity is very low. They are not addictive and I would rate them very low in their potential for harm.

  Q428  Dr Iddon: So what you are saying to me is that in 2005 the Misuse of Drugs Act put magic mushrooms into the wrong classification because the only reason for putting them in Class A was they contained psilocin and psilocybin. Do you agree with me?

  Professor Blakemore: I would say they are in a classification that if one could look at all the evidence for harm available now, including social harms, one would say it is wrong.

  Q429  Dr Iddon: So the Government were not using evidence based science to put them in Class A.

  Professor Blakemore: I am sure they were using the evidence that was available to them at the time. The question is whether that evidence was fully formulated and was quantitatively organised in a way that would inform the decision well.

  Chairman: The ACMD are supposed to review these things.

  Q430  Mr Devine: ACPO said it would support a decision to re-classify ecstasy as Class B as long ago as 2001. Why do you think this decision has not been taken?

  Mr Hayman: I am trying to be really helpful on this but I do not know. I gave evidence to the Home Affairs Select Committee around that time and in fact the document that I alluded to earlier in answer to one of the earlier questions about the ACPO policy was in preparation for the appearance in front of the Home Affairs Select Committee. That is where it was positioned. Again, I do not know why that has not proceeded.

  Q431  Mr Devine: Have you asked ACMD to re-consider this?

  Mr Hayman: It is not a matter for us to ask that.

  Q432  Mr Devine: Do you not take the views of your organisation to that body?

  Mr Hayman: Our positioning of our view on ecstasy was in direct response to a question about it looking to advance it or lobby for that. We were asked that question and that is how we felt at the time. I would have to go back to the membership to see whether it is a valid view. My understanding was that as a professional body it was not really appropriate for us to be saying to ACMD what we should or should not be doing; it works in a slightly different way to that.

  Q433  Mr Devine: Are you on there as an individual or are you on there from the police?

  Mr Hayman: It is our body that is represented as a professional body. It just so happens I had the privilege to be asked when I became the chair of it to sit on it.[1]

  Q434 Mr Devine: What about the others on the panel, do you accept the view of the ACMD chairman that the revaluation of the classification of ecstasy is not viable because of the lack of scientific evidence?

  Professor Blakemore: If we had a flexible system of classification that would respond quickly to changing scientific evidence then there could always be the case for moving the classification of drugs. My own view—my personal view, not of the Medical Research Council—is that on the basis of present evidence ecstasy should not be a Class A drug. It is at the bottom of the scale of harm. There has been a great deal of scientific work on ecstasy in the last few years but it is still a confused field. I think John would agree that we do not have adequate evidence on the long term consequences; there is a particular concern there.

  Q435  Chairman: Andy, in 2003 (this is the issue about whether cannabis is a gateway drug) you made a very interesting comment when you were chair of the ACPO Drugs Committee, that "The theory of `gateway drugs', ie someone starts with cannabis and then migrates onto a more serious drug does not stand up". We commissioned a report from RAND who said exactly the same thing. In oral evidence to us this year the chairman of ACMD said, "We know that the early use of nicotine and alcohol is a much wider gateway to subsequent misuse of drugs than cannabis or anything like that". Do you stand by those comments? I wonder if the other two members of the panel would also stand by those comments.

  Mr Hayman: Those comments were made on the basis of what I had read. I have no professional qualification at all to make that statement but I read it in the research and that was my interpretation having read that research. That is why I made that statement. If we had a cop making those kinds of statements that would be very safe.

  Professor Strang: I am afraid my answer is that it all depends on what you mean by a "gateway drug". It is a correct observation that people who are using heroin went through gates on the way to where they are now. The crucial question is: if you had had the power to stop them going through that gate would it have altered their subsequent journey? It really does come back to experiments and opportunities that are thrown up. I presume going to primary school is a gateway to being a heroin addict but you are not implying there is a causal relationship between the one and the other and that is the bit that is missing from most of the debate. There will be individuals where you can see it in that individual's personal development, but that does not mean it is a generaliseable finding.

  Professor Blakemore: I think one should ask what is likely to be the causal basis of a real gateway effect. I cannot think of a chemical or physiological basis. The obvious basis is supply. If you are buying your first drug from a person who then tries to persuade you to use a "better" one and a stronger one then there is a causal relationship which is determined by the supplier. The fact is that as I understand it cannabis supply is, to a large extent, rather different from the supply of harder drugs. There is numerical evidence though. One can look to Holland where the attitude to cannabis use is even more relaxed than it is in this country and where cannabis use amongst the population is a little less than it is in this country even though it is more easily available. Hard drug use is about one third of the rate in this country. So the availability and the legal acceptance of a soft drug is clearly in that case not automatically leading to a high rate of hard drug use.

  Q436  Mr Newmark: So you are saying there is nothing physical, ie that taking something that has a chemical reaction on you physiologically does not cause a certain potential of people in the population then to want to crave something harder after having used that other drug.

  Professor Blakemore: I am sure that John can answer that better than me but first of all I would say that cannabis is not classically an addictive drug; it can be very habit forming and produce dependencies but it does not trigger the same mechanisms of the requirement for further and higher doses that the opiates do. I do not know about cross-craving between drugs and whether there is a physiological basis for that.

  Professor Strang: I think it is ever so important for you to get away from this notion (if you have it at all) that there is just a vulnerable percentage of the population who might develop problems and it is all right for everybody else. With alcohol and tobacco you can look at it exquisitely. With both price and availability and public acceptability the levels of use will go up and down over the decades and the amount of harm that society approves goes up and down and the amount of addiction or dependence out there in society goes up and down. You can measure it against price: roughly every 1% up you get ½% down. You suddenly think that this is not a commodity where there are just some people with the equivalent of brittle bones; this is something distributed across the population. There will be vulnerable individuals who are more likely to come a cropper and that has to be laid on top of it, but that does not explain the problems of alcohol, tobacco or illicit drug use in society.

  Q437  Mr Devine: Do you say there has been a lot of scientific evidence about re-classification of ecstasy? My understanding is that something like nearly 60% of young people going out at the weekend could be taking this going to clubs and pubs and what have you with apparently no ill effect. Is there a political reason why we are not re-classifying ecstasy?

  Professor Blakemore: I think there is always a defensible political reason to be cautious about making any substance which might have dangerous effects more easily available. That is a natural conservatism and is entirely defensible. I do think the accruing evidence on ecstasy has increased confidence in one's judgment that this is not a very highly dangerous drug in the way that crack cocaine and heroin clearly are and yet it is in the same category as crack cocaine and heroin at the moment.

  Chairman: Thank you very much indeed Colin Blakemore, John Strang and Andy Hayman. I am sorry the session has been rushed but, as always when you have an interesting subject, you want to go on and on and on.

1   Note by the witness: In fact, under Cabinet Office Guidelines, and public appointments rules, I was appointed to ACMD in a personal capacity, although clearly, as with all other ACMD members, my professional role, knowledge and experience will have played a key part in being selected for appointment. The Office of the Commissioner for Public Appointments approves the process. Back

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