Select Committee on Science and Technology Fifth Report

6  Evidence base for classification

Evidence for deterrent effect

78. The stated purpose of the classification system is to classify harmfulness so that the penalties for possession and trafficking are proportionate to the harm associated with a particular drug.[152] Although it is implicit in this policy that placing drugs in a higher Class has some kind of deterrent effect, we found little evidence to support this. Transform Drug Policy Foundation asserted that the ABC classification system was "based upon the false assumptions underlying historical prohibition of specific drugs".[153] Steve Rolles, information officer for Transform, also told us: "there is no research at all—not a single piece of research ever done by the Home Office that I am aware of—into the effectiveness of the classification system as a deterrent and the independent research that we do have—what little there is—suggests that at best it is a marginal impact on drug taking decisions".[154] The Home Office Minister Vernon Coaker was unable to provide us with any specific evidence to the contrary.

79. In oral evidence, Professor David Nutt, Chairman of the ACMD Technical Committee also said: "I think the evidence base for classification producing a deterrent is not strong",[155] while Andy Hayman, Chair of the ACPO Drugs Committee, told us: "I cannot envisage any user - a dependent user, that is - having any kind of thought as to whether it was a Class A, B or C drug they were consuming".[156] The Runciman report concluded that "such evidence as we have assembled about the current situation and the changes that have taken place in the last 30 years all point to the conclusion that the deterrent effect of the law has been very limited".[157] Charles Clarke, the then Home Secretary, appeared to acknowledge this problem in the exchanges following his statement regarding the classification of cannabis in January 2006. He said: "The key question is how best to reduce the use of cannabis. The subsidiary question is: what role does classification, as opposed to education, health and policing campaigns and so on, play in that?".[158] However, the mental health charity Rethink pointed out that even at a global level there was "very little knowledge […] on the relative effectiveness of legal status, drugs education and information campaigns on reducing usage levels".[159]

80. The penalties associated with classification can have serious consequences for users in terms of sentencing. As noted above, the classification system also plays a significant role in directing expenditure of the £1.5 billion that the Government spends annually on tackling drugs. We have found no solid evidence to support the existence of a deterrent effect, despite the fact that it appears to underpin the Government's policy on classification. In view of the importance of drugs policy and the amount spent on enforcing the penalties associated with the classification system, it is highly unsatisfactory that there is so little knowledge about the system's effectiveness.


81. The lack of evidence of a deterrent effect is particularly significant in view of the Government's eagerness to use the classification system to 'send out signals'. As Lesley King-Lewis, Chief Executive of Action on Addiction, pointed out: "We do not even know if the public see that if a drug is in Class A is that more of a deterrent or is it actually an attraction?".[160] Nevertheless, the then Home Secretary cited as justification for the review of the classification system announced in January 2006 the fact that "Decisions on classification often address different or conflicting purposes, and too often send strong but confusing signals to users and others about the harms and consequences of using a particular drug".[161] Home Office Minister Vernon Coaker also insisted that although the purpose of classification was to "categorise drugs according to harm", it "does send out messages; it does send out signals to people, in a way which people understand".[162] Mr Coaker further posed the question: "is not part of any system with respect to drugs […] not only trying to send messages out to people who misuse drugs but also about trying to send messages out to people out there in the community?".[163]

82. Transform Drug Policy Foundation was of the view that "Criminal law is supposed to prevent crime, not 'send out' public health messages" and warned that it could backfire by "fostering distrust of police and public health messages amongst young people".[164] We are inclined to agree. The Government's desire to use the Class of a particular drug to send out a signal to potential users or dealers does not sit comfortably with the claim that the primary objective of the classification system is to categorise drugs according to the comparative harm associated with their misuse. It is also incompatible with the Government's stated commitment to evidence based policy making since it has never undertaken research to establish the relationship between the Class of a drug and the signal sent out and there is, therefore, no evidence base on which to draw in making these policy decisions.

Evidence base for classification decisions


83. The ACMD told us that it makes use of a variety of sources and types of evidence in its deliberations over control of substances under the MDA. These include:

84. The ACMD told us that the evidence base available for making decisions about classification was often inadequate. For example, Sir Michael, ACMD Chairman, said of the decision to clarify the law resulting in fresh magic mushrooms being placed in Class A: "It may be better in B rather than A. The trouble is that the evidence now is so old. It all dates back to the 1960s and there was not very much evidence then".[166] On the matter of why psilocin, one of the hallucinogenic compounds found in magic mushrooms, was in Class A, Sir Michael told us: "it is there because it is there […] there have been very few publications on psilocin. It has hardly been investigated at all".[167] Nevertheless, as Martin Barnes, Chief Executive of DrugScope and a member of the ACMD also pointed out, when the ACMD has called for more investment in research, the Government has not always responded positively. He told us that the Government had taken two years to publish its response to the ACMD's Hidden Harm report which recommended more research into the issue of the effects of drug use amongst parents of young people, ultimately concluding "that we have enough research on that issue".[168]

85. Whilst physical harmfulness can usually be assessed on the basis of existing pharmacological, clinical and epidemiological literature, the ACMD warned that it could be more difficult to establish the dependence-producing potential of a substance on the basis of such sources. The ACMD further told us that evidence about social harms tended to be "the weakest data-set because of the inherent problems in gathering relevant information". For example, there is often little reliable evidence "about the quality and potency of material used by consumers, their pattern of consumption, and the social consequences of their use".[169] The ACMD explained that while "in some instances the Council has commissioned primary research into areas of particular significance", in other cases it "has had to rely on anecdotal evidence provided by individual Council members or others with expertise in the particular field".[170] We note that, despite the difficulties of conducting such research, there are a substantial number of publications focussing on social harms carried out under the auspices of bodies such as the National Addiction Centre and EMCDDA. If, as the ACMD Chairman indicated to us, the Council's work has been seriously hindered by the lack of evidence, the ACMD should have been far more vocal in pressing Ministers to ensure that more research was commissioned to fill the key gaps in the evidence base.

UK investment in research

86. Charles Clarke, the then Home Secretary, stated in January 2006 following the announcement that he would be launching a review of the classification system: "I want to emphasise to the House the importance of evidence and research on this subject".[171] However, Professor Strang, Director of the National Addiction Centre, described UK expenditure on addiction research as "an embarrassment" which caused "people like myself and my colleagues [to] get lured away" to the US and Australia, where investment was "orders of magnitude greater".[172] Professor Blakemore confirmed this:

"In 2003 to 2004 [the MRC] spent £2 million in total out of a £450 million budget on addiction research. The total budget of the three NIH [US National Institutes of Health] institutes that work in this area is $2.9 billion so even if one takes a conservative estimate of how much of that is actually devoted to addiction research it comes out to about five hundred times higher than in the UK—in other words about a hundred times more per head of the population."[173]

Professor Nutt, Chair of the ACMD Technical Committee, had previously estimated that there was a "1000 fold differential" between UK and US public expenditure on addiction research.[174]

87. Professor Strang emphasised that this had serious consequences for the UK: "The lack of policy related research severely handicaps the ACMD and it severely handicaps government's process of making decisions".[175] Indeed, Paul Flynn MP described Government policy decisions on illegal drugs as "largely evidence free".[176] The charity Rethink told us: "The government has singularly failed to commission [research] looking at the impact of cannabis on mental health. No major study so far on this issue has hence originated from the UK. This seems a significant failure on the part of the Government".[177] The observation that the UK does not invest sufficient amounts in research is not new. Authors of the Runciman report published in 2000 were similarly forthright about the UK's failure to invest in research and evaluation, saying: "we have been forcibly struck by the lack of research and the weakness of the information base about drug use in the UK […] Equally striking is the anomaly that the largest part of the drugs budget is spent on enforcement without the necessary resources being applied to the proper evaluation of its success or failure".[178] UK investment in addiction research is woefully inadequate. The Government's failure to ensure that sufficient resources are devoted to building the evidence base to underpin drugs policy is at odds with its commitment to adopt an evidence based approach. We were pleased to hear the Minister agree in evidence to us that addiction research was "something we should look at" and encourage him to do so as soon as possible.[179]


88. In light of the weakness of the evidence base, it was disappointing to hear that opportunities were being missed to gather data to evaluate the effect of changes in drug-related policies. Professor John Strang, Director of the National Addiction Centre, told us: "we are ill informed about whether the changes [in drug classifications] have made [the situation] better or worse", particularly with respect to cannabis.[180] He argued that, although "the political process sometimes needs to make decisions with a pace that does not fit science and the gathering of evidence […] when a decision is made I would expect to know three years down the line had the trajectory carried on going up or had it taken off".[181] DrugScope cited another missed opportunity: "A case in point might be ketamine, controlled in January 2006 as a Class C drug, but with no prevalence data against which to track the impact of control".[182] The Government has been remiss in failing to conduct a proper evaluation of the impact of its policy decisions in this area and has, as a result, missed out on opportunities to gather valuable data to improve policy making in the future.


89. The then Home Office Minister Caroline Flint stated in response to a question asking what research had been promoted by the ACMD in recent years that the Council "does not actively promote any external research" but "does commission its own research".[183] Professor Nutt, Chairman of the ACMD Technical Committee told us, however, that the Council did "not have the resources to do extensive novel research". Professor Nutt also suggested that one reason for the "mismatch between research needs in addiction and research outcomes" was the fact that "the ACMD is embedded in the Home Office and the Home Office does not have any particular representation at the MRC [Medical Research Council]".[184] When questioned on this, Sir Michael admitted that the Council had been "remiss" in not building better links with the Research Councils, telling us "we probably should and try to ensure that there are some formal channels of communication between the ACMD, the MRC and the ESRC [Economic and Social Research Council]".[185] The ACMD also told us that links with the Department of Health had been important in facilitating the promotion of research of relevance to drugs policy. We note that the proposed merger of the NHS research and MRC budgets provides an opportunity to strengthen these relations further.

90. The need to stimulate investment in research to support policy development has been a recurring theme in each of the case studies. We will therefore consider it in more detail in the over-arching Report on the Government's handling of scientific advice, risk and evidence. In respect of this case study, it is essential that the ACMD and Home Office develop better relationships with the Research Councils, particularly the Medical Research Council and the Economic and Social Research Council, and further improve relations with the Department of Health. The fact that the Council has not devoted much effort to this in the past has been a contributing factor to the weakness of the UK evidence base on drugs policy and addiction.

91. Finally, we note that Sir Michael argued strongly that we should take into account the fact that "This is an area in which it is extraordinarily difficult to do research", giving the example of the ethical and practical problems posed by volunteer studies involving ecstasy.[186] We do not dispute that research of that nature would present significant challenges but we also note that other methodologies have been successfully employed which do not entail such ethical difficulties. There are, for example, large numbers of publications based on observational studies of patterns of use among existing users, prospective studies of patterns of use or harm, policy change studies and clinical intervention studies. We do not underestimate the challenges involved in undertaking scientific studies concerning the misuse of illegal drugs, but the Government must not use this as an excuse for not fulfilling its obligations to undertake proper evaluations of the impacts of its policies and to fund research for the public good.

152   Q 109 Back

153   Ev 58 Back

154   Q 447 Back

155   Q 130 Back

156   Q 387 Back

157   Runciman Report, para 4 Back

158   HC Deb, 19 Jan 2006, col 994 Back

159   Ev 71 Back

160   Q 440 Back

161   HC Deb, 19 Jan 2006, col 983 Back

162   Q 1228 Back

163   Q 1229 Back

164   Ev 64 Back

165   Ev 96 Back

166   Q 230 Back

167   Q 224 Back

168   Q 451 Back

169   Ev 97 Back

170   As above Back

171   HC Deb, 19 Jan 2006, col 996 Back

172   Q 400 Back

173   Q 417 Back

174   Not published Back

175   Q 411 Back

176   Ev 75 Back

177   Ev 71 Back

178   Runciman Report, para 4 Back

179   Q 1218 Back

180   Q 376 Back

181   Q 377 Back

182   Ev 91 Back

183   HC Deb, 24 Jun 2004, col 1503W Back

184   Q 172 Back

185   Q 221 Back

186   Q 242 Back

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