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Proper assessment of the harms caused by the misuse of drugs can inform policy makers in health, policing, and social care. We aimed to apply multicriteria decision analysis (MCDA) modelling to a range of drug harms in the UK. Method Members of the Independent Scientific Committee on Drugs, including two invited specialists, met in a 1-day interactive workshop to score 20 drugs on 16 criteria: nine related to the harms that a drug produces in the individual and seven to the harms to others. Drugs were scored out of 100 points, and the criteria were weighted to indicate their relative importance. Findings MCDA modelling showed that heroin, crack cocaine, and metamfetamine were the most harmful drugs to individuals (part scores 34, 37, and 32, respectively), whereas alcohol, heroin, and crack cocaine were the most harmful to others (46, 21, and 17, respectively). Overall, alcohol was the most harmful drug (overall harm score 72), with heroin (55) and crack cocaine (54) in second and third places. Interpretation These findings lend support to previous work assessing drug harms, and show how the improved scoring and weighting approach of MCDA increases the differentiation between the most and least harmful drugs. However, the findings correlate poorly with present UK drug classification, which is not based simply on considerations of harm.
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Articles Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
Published Online
November 1, 2010
See Online/Comment
Unit, Imperial College, London,
UK (Prof D J Nutt FMedSci); UK
Expert Adviser to the European
Monitoring Centre for Drugs
and Drug Addiction (EMCDDA),
Lisbon, Portugal (L A King PhD);
and Department of
Management, London School
of Economics and Political
Science, London, UK
(L D Phillips PhD)
Correspondence to:
Prof David J Nutt,
Neuropsychopharmacology Unit,
Imperial College London,
Burlington-Danes Building,
Hammersmith Hospital, Du Cane
Road, London W12 0NN, UK
Drug harms in the UK: a multicriteria decision analysis
David J Nutt, Leslie A King, Lawrence D Phillips, on behalf of the Independent Scientifi c Committee on Drugs
Background Proper assessment of the harms caused by the misuse of drugs can inform policy makers in health,
policing, and social care. We aimed to apply multicriteria decision analysis (MCDA) modelling to a range of drug
harms in the UK.
Method Members of the Independent Scientifi c Committee on Drugs, including two invited specialists, met in a
1-day interactive workshop to score 20 drugs on 16 criteria: nine related to the harms that a drug produces in the
individual and seven to the harms to others. Drugs were scored out of 100 points, and the criteria were weighted to
indicate their relative importance.
Findings MCDA modelling showed that heroin, crack cocaine, and metamfetamine were the most harmful drugs to
individuals (part scores 34, 37, and 32, respectively), whereas alcohol, heroin, and crack cocaine were the most harmful
to others (46, 21, and 17, respectively). Overall, alcohol was the most harmful drug (overall harm score 72), with
heroin (55) and crack cocaine (54) in second and third places.
Interpretation These fi
ndings lend support to previous work assessing drug harms, and show how the improved scoring
and weighting approach of MCDA increases the diff erentiation between the most and least harmful drugs. However, the
ndings correlate poorly with present UK drug classifi cation, which is not based simply on considerations of harm.
Funding Centre for Crime and Justice Studies (UK).
Drugs including alcohol and tobacco products are a major
cause of harms to individuals and society. For this reason,
some drugs are scheduled under the United Nations 1961
Single Convention on Narcotic Drugs and the 1971
Convention on Psychotropic Substances. These controls
are represented in UK domestic legislation by the 1971
Misuse of Drugs Act (as amended). Other drugs, notably
alcohol and tobacco, are regulated by taxation, sales, and
restrictions on the age of purchase. Newly available drugs
such as mephedrone (4-methylmethcathinone) have
recently been made illegal in the UK on the basis of
concerns about their harms, and the law on other drugs,
particularly cannabis, has been toughened because of
similar concerns.
To provide better guidance to policy makers in health,
policing, and social care, the harms that drugs cause
need to be properly assessed. This task is not easy because
of the wide range of ways in which drugs can cause harm.
An attempt to do this assessment engaged experts to
score each drug according to nine criteria of harm,
ranging from the intrinsic harms of the drugs to social
and health-care costs.1 This analysis provoked major
interest and public debate, although it raised concerns
about the choice of the nine criteria and the absence of
any diff erential weighting of them.2
To rectify these drawbacks we undertook a review of
drug harms with the multicriteria decision analysis
(MCDA) approach.3 This technology has been used
successfully to lend support to decision makers facing
complex issues characterised by many, confl icting
objectives—eg, appraisal of policies for disposal of
nuclear waste.4 In June, 2010, we developed the
multicriteria model during a decision conference,5 which
is a facilitated workshop attended by key players, experts,
and specialists who work together to create the model
and provide the data and judgment inputs.
Study design
The analysis was undertaken in a two-stage process. The
choice of harm criteria was made during a special
meeting in 2009 of the UK Advisory Council on the
Misuse of Drugs (ACMD), which was convened for this
purpose. At this meeting, from fi rst principles and with
the MCDA approach, members identifi ed 16 harm
criteria (fi gure 1). Nine relate to the harms that a drug
produces in the individual and seven to the harms to
others both in the UK and overseas. These harms are
clustered into fi ve subgroups representing physical,
psychological, and social harms. The extent of individual
harm is shown by the criteria listed as to users, whereas
most criteria listed as to others take account indirectly of
the numbers of users. An ACMD report explains the
process of developing this model.6
In June, 2010, a meeting under the auspices of the
Independent Scientifi c Committee on Drugs (ISCD)—a
new organisation of drug experts independent of
government interference—was convened to develop the
MCDA model and assess scores for 20 representative
drugs that are relevant to the UK and which span the
range of potential harms and extent of use. The expert
group was formed from the ISCD expert committee plus
two external experts with specialist knowledge of legal
For more on the Independent
Scientifi c Committee on Drugs
see: http://www.drugscience.
2 Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
highs (webappendix). Their experience was extensive,
spanning both personal and social aspects of drug harm,
and many had substantial research expertise in addiction.
All provided independent advice and no confl icts of
interest were declared. The meeting’s facilitator was an
independent specialist in decision analysis modelling.
He applied methods and techniques that enable groups
to work eff ectively as a team, enhancing their capability
to perform,7 thereby improving the accuracy of individual
judgments. The group scored each drug on each harm
criterion in an open discussion and then assessed the
relative importance of the criteria within each cluster and
across clusters. They also reviewed the criteria and the
defi nitions developed by the ACMD. This method
resulted in a common unit of harm across all the criteria,
from which a new analysis of relative drugs harms was
achieved. Very slight revisions of the defi nitions were
adopted, and panel 1 shows the fi nal version.
Scoring of the drugs on the criteria
Drugs were scored with points out of 100, with
100 assigned to the most harmful drug on a specifi c
criterion. Zero indicated no harm. Weighting sub-
sequently compares the drugs that scored 100 across all
the criteria, thereby expressing the judgment that some
drugs scoring 100 are more harmful than others.
In scaling of the drugs, care is needed to ensure that
each successive point on the scale represents equal
increments of harm. Thus, if a drug is scored at 50, then it
should be half as harmful as the drug that scored 100.
Because zero represents no harm, this scale can be
regarded as a ratio scale, which helps with interpretation of
weighted averages of several scales. The group scored the
drugs on all the criteria during the decision conference.
Consistency checking is an essential part of proper
scoring, since it helps to minimise bias in the scores and
encourages realism in scoring. Even more important is
the discussion of the group, since scores are often changed
from those originally suggested as participants share their
diff erent experiences and revise their views. Both during
scoring and after all drugs have been scored on a criterion,
it is important to look at the relativities of the scores to see
whether there are any obvious discrepancies.
Weighting of the criteria
Some criteria are more important expressions of harm
than are others. More precision is needed, within the
context of MCDA, to enable the assessment of weights on
the criteria. To ensure that assessed weights are meaningful,
the concept of swing weighting is applied. The purpose of
weighting in MCDA is to ensure that the units of harm on
the diff erent preference scales are equivalent, thus enabling
weighted scores to be compared and combined across the
criteria. Weights are, essentially, scale factors.
MCDA distinguishes between facts and value
judgments about the facts. On the one hand, harm
expresses a level of damage. Value, on the other hand,
indicates how much that level of damage matters in a
particular context. Because context can aff ect assess-
ments of value, one set of criterion weights for a
particular context might not be satisfactory for decision
making in another context. It follows then, that two
stages have to be considered. First, the added harm
going from no harm to the level of harm represented by
a score of 100 should be considered—ie, a straight-
forward assessment of a diff erence in harm. The next
step is to think about how much that diff erence in harm
matters in a specifi c context. The question posed to the
group in comparing the swing in harm from 0 to 100 on
one scale with the swing from 0 to 100 on another scale
was: “How big is the diff erence in harm and how much
do you care about that diff erence?”
During the decision conference participants assessed
weights within each cluster of criteria. The criterion
within a cluster judged to be associated with the largest
swing weight was assigned an arbitrary score of 100.
Then, each swing on the remaining criteria in the
cluster was judged by the group compared with the
100 score, in terms of a ratio. For example, in the
cluster of four criteria under the category physical
harm to users, the swing weight for drug-related
mortality was judged to be the largest diff erence of the
four, so it was given a weight of 100. The group judged
the next largest swing in harm to be in drug-specifi c
mortality, which was 80% as great as for drug-related
Drug-specific mortality
Drug-related mortality
Drug-specific damage
Drug-related damage
Drug-specific impairment of mental functioning
Drug-related impairment of mental functioning
Loss of tangibles
Loss of relationships
Environmental damage
Economic cost
To users
To others
Overall harm
Physical and psychological
Family adversities
International damage
Figure 1: Evaluation criteria organised by harms to users and harms to others, and clustered under physical,
psychological, and social eff ects
See Online for webappendix
Articles Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
mortality, so it was given a weight of 80. Thus, the
computer multiplied the scores for all the drugs on the
drug-related mortality scale by 0·8, with the result that
the weighted harm of heroin on this scale became 80
as compared with heroin’s score of 100 on drug-specifi c
mortality. Next, the 100-weighted swings in each cluster
were compared with each other, with the most harmful
drug on the most harmful criterion to users compared
with the most harmful drug on the most harmful
criterion to others. The result of assessing these weights
was that the units of harm on all scales were equated. A
nal normalisation preserved the ratios of all weights, but
ensured that the weights on the criteria summed to 1·0.
The weighting process enabled harm scores to be combined
within any grouping simply by adding their weighted
scores. Dodgson and colleagues3 provide further guidance
on swing weighting. Scores and weights were input to the
Hiview computer program, which calculated the weighted
scores, provided displays of the results, and enabled
sensitivity analyses to be done.
Role of the funding source
The sponsor of the study had no role in study design,
data collection, data analysis, data interpretation, or
writing of the report. All authors had full access to all the
data in the study, and had fi nal responsibility for the
decision to submit for publication.
Figure 1 shows the 16 identifi ed harm criteria. Figure 2
shows the total harm score for all the drugs and the part-
score contributions to the total from the subgroups of
harms to users and harms to others. The most harmful
drugs to users were heroin (part score 34), crack cocaine
(37), and metamfetamine (32), whereas the most harmful
Panel 1: Evaluation criteria and their defi nitions
Drug-specifi c mortality
Intrinsic lethality of the drug expressed as ratio of lethal dose
and standard dose (for adults)
Drug-related mortality
The extent to which life is shortened by the use of the drug
(excludes drug-specifi c mortality)—eg, road traffi c accidents,
lung cancers, HIV, suicide
Drug-specifi c damage
Drug-specifi c damage to physical health—eg, cirrhosis,
seizures, strokes, cardiomyopathy, stomach ulcers
Drug-related damage
Drug-related damage to physical health, including
consequences of, for example, sexual unwanted activities and
self-harm, blood-borne viruses, emphysema, and damage
from cutting agents
The extent to which a drug creates a propensity or urge to
continue to use despite adverse consequences (ICD 10 or
Drug-specifi c impairment of mental functioning
Drug-specifi c impairment of mental functioning—eg,
amfetamine-induced psychosis, ketamine intoxication
Drug-related impairment of mental functioning
Drug-related impairment of mental functioning—eg, mood
disorders secondary to drug-user’s lifestyle or drug use
Loss of tangibles
Extent of loss of tangible things (eg, income, housing, job,
educational achievements, criminal record, imprisonment)
Loss of relationships
Extent of loss of relationship with family and friends
Extent to which the use of a drug increases the chance of
injuries to others both directly and indirectly—eg, violence
(including domestic violence), traffi c accident, fetal harm,
drug waste, secondary transmission of blood-borne viruses
(Continues in next column)
(Continued from previous column)
Extent to which the use of a drug involves or leads to an
increase in volume of acquisitive crime (beyond the use-of-
drug act) directly or indirectly (at the population level, not
the individual level)
Environmental damage
Extent to which the use and production of a drug causes
environmental damage locally—eg, toxic waste from
amfetamine factories, discarded needles
Family adversities
Extent to which the use of a drug causes family adversities—
eg, family breakdown, economic wellbeing, emotional
wellbeing, future prospects of children, child neglect
International damage
Extent to which the use of a drug in the UK contributes to
damage internationally—eg, deforestation, destabilisation of
countries, international crime, new markets
Economic cost
Extent to which the use of a drug causes direct costs to the
country (eg, health care, police, prisons, social services,
customs, insurance, crime) and indirect costs (eg, loss of
productivity, absenteeism)
Extent to which the use of a drug creates decline in social
cohesion and decline in the reputation of the community
ICD 10=International Classifi cation of Diseases, tenth revision. DSM IV=Diagnostic and
Statistical Manual of Mental Disorders, fourth revision.
For more on Hiview see http://
4 Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
to others were alcohol (46), crack cocaine (17), and heroin
(21). When the two part-scores were combined, alcohol
was the most harmful drug followed by heroin and crack
cocaine (fi gure 2).
Another instructive display is to look at the results
separately for harm to users and to others, but in a two-
dimensional graph so that the relative contribution to
these two types of harm can be seen clearly (fi gure 3).
The most harmful drug to others was alcohol by a wide
margin, whereas the most harmful drug to users was
crack cocaine followed closely by heroin. Metamfetamine
was next most harmful to users, but it was of little
comparative harm to others. All the remaining drugs
were less harmful either to users or to others, or both,
than were alcohol, heroin, and crack cocaine (fi gure 3).
Because this display shows the two axes before
weighting, a score on one cannot be compared with a
score on the other, without knowing their relative scale
Figure 4 shows the contributions that the part scores
make on each criterion to the total score of each drug.
Alcohol, with an overall score of 72, was judged to be
most harmful, followed by heroin at 55, then crack
cocaine with a score of 54. Only eight drugs scored,
overall, 20 points or more. Drug-specifi c mortality was a
substantial contributor to fi ve of the drugs (alcohol,
heroin, γ hydroxybutyric acid [GHB], methadone, and
butane), whereas economic cost contributed heavily to
alcohol, heroin, tobacco, and cannabis.
The results from this MCDA analysis show the harms of
a range of drugs in the UK. Our fi ndings lend support to
the conclusions of the earlier nine-criteria analysis
undertaken by UK experts1 and the output of the Dutch
addiction medicine expert group.8 The Pearson cor-
relation coeffi cient between Nutt and colleagues’ 2007
study1 and the new analysis presented here for the
15 drugs common to both studies is 0·70. One reason
for a less-than-perfect correlation is that the scores from
Nutt and colleagues’ previous study were based on four-
point ratings (0=no risk, 1=some risk, 2=moderate risk,
and 3=extreme risk). The ISCD scoring process was
based on 0–100 ratio scales, so they contain more
information than the ratings do.
Throughout Nutt and colleagues’ 2007 paper, harm
and risk are used interchangeably, but in the ISCD
work, risk was not considered because it is susceptible
to varying interpretations. For example, the British
Medical Association defi nes risk as the probability that
something unpleasant will happen.9 Thus, assessors
from Nutt and colleagues’ 2007 work might have
interpreted their rating task diff erently from the scoring
task of the ISCD experts. Furthermore, in Nutt and co-
workers’ 2007 study, ratings were simply averaged
across the nine criteria (called parameters in the report),
three each for physical harm, dependence, and social
harms, whereas diff erential weights were applied to the
criteria in this ISCD study, as is shown in the key of
Crack cocaine
Anabolic steroids
Overall harm score
55 54
27 26
20 19
15 15 14 13 11 910 9776
Harm to users (CW 46)
Harm to others (CW 54)
Figure 2: Drugs ordered by their overall harm scores, showing the separate contributions to the overall scores of harms to users and harm to others
The weights after normalisation (0–100) are shown in the key (cumulative in the sense of the sum of all the normalised weights for all the criteria to users, 46; and for
all the criteria to others, 54). CW=cumulative weight. GHB=γ hydroxybutyric acid. LSD=lysergic acid diethylamide.
Articles Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
gure 4. Despite these many diff erences between the
two studies, there is some degree of linear association
between both sets of data.
The correlations between the Dutch addiction medicine
expert group2 and ISCD results are higher: 0·80 for
individual total scores and 0·84 for population total scores.
As with Nutt and colleagues’ 2007 study, the Dutch experts
applied four-point rating scales to 19 drugs. However, they
used fi ve criteria: acute toxicity, chronic toxicity, addictive
potency, social harm at individual level, and social harm at
population level. Simple averages produced two overall
mean harm ratings, one each for individuals and for
populations. The probable explanation for the greater
correlation between the ISCD and Dutch data lies in the
greater relative ranges of the overall results than in Nutt
and co-workers’ 2007 study. The highest and lowest overall
harm scores in the ISCD study are 72 for alcohol and 5 for
mushrooms, which is a ratio of about 14:1; whereas in
Nutt and colleagues’ study it was a ratio of just over 3:1,
from 2·5 for heroin to 0·8 for khat. The highest and lowest
scores for the Dutch individual ratings were 2·63 for crack
cocaine and 0·40 for mushrooms, which is a ratio of 6·6:1;
and for the population ratings 2·41 for crack cocaine and
0·31 for mushrooms, which is a ratio of 7·8:1. The ratio
scaling in the ISCD study spanned a wider range, making
the three most harmful drugs—alcohol, heroin, and crack
cocaine—much more harmful relative to the other drugs
than can be expressed with rating scales, so that additional
information stretched the scatterplot in one dimension,
making it seem more linear. Additionally, because the
Dutch scale attributes only a quarter of the scores to social
factors, whereas in the ISCD scoring these factors
comprise nearly half of the scores (seven of 16 criteria),
drugs such as alcohol which have a major eff ect will rank
more highly in the ISCD analysis, with tobacco ranked
lower because its harms are mainly personal.
The correlations between the ISCD overall scores and
the present classifi cation of drugs based on revisions to
the UK Misuse of Drugs Act (1971) is 0·04, showing that
there is eff ectively no relation. The ISCD scores lend
support to the widely accepted view10,11 that alcohol is an
extremely harmful drug, both to users and society; it
scored fourth on harms to users and top for harms to
society, making it the most harmful drug overall. Even in
terms of toxic eff ects alone, Gable12 has shown that, on the
basis of a safety ratio, alcohol is more lethal than many
010 20 30 40 50 60 70 80 90
Score for harm to others
Score for harm to users
Crack cocaine
Anabolic steroids
Figure 3: Drugs shown for their harm to users and harm to others
LSD=lysergic acid diethylamide. GHB=γ hydroxybutyric acid.
6 Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
illicit drugs, such as cannabis, lysergic acid diethylamide
(LSD), and mushrooms.
The MCDA process provides a powerful means to deal
with complex issues that drug misuse presents. The
expert panel’s scores within one criterion can be to some
extent validated by reference to published work. For
example, we compared the 12 substances in common
between this study and those in Gable’s study,12 who for
20 substances identifi ed a safety ratio—the ratio of an
acute lethal dose to the dose commonly used for non-
medical purposes. The log10 of that ratio shows a
correlation of 0·66 with the ISCD scores on the criterion
drug-specifi c mortality, providing some evidence of
validity of the ISCD input scores.
We also investigated drug-specifi c mortality estimates
in studies of human beings.13 These estimates show a
strong correlation with the group input scores: the mean
fatality statistics from 2003 to 2007 for fi ve substances
(heroin, cocaine, amfetamines, MDMA/ecstasy, and
cannabis) show correlations with the ISCD lethality
scores of 0·98 and 0·99, for which the substances
recorded on the death certifi cates were among other
mentions or sole mentions, respectively.
A comparison of the ICSD experts’ ratings on the
dependence criterion with lifetime dependence reported
in the US survey by Anthony and co-workers14 showed a
correlation of 0·95 for the fi ve drugs—tobacco, alcohol,
cannabis, cocaine, and heroin—that were investigated in
both studies, showing the validity of the MCDA input
scores for those substances.
Drug-specifi c and drug-related harms for some drugs
can be estimated from health data and other data that
show alcohol, heroin, and crack cocaine as having much
larger eff ects than other drugs.15 Social harms are harder
to ascertain, although estimates based on road traffi c
and other accidents at home, drug-related violence,16 and
costs to economies in provider countries (eg, Colombia,
Afghanistan, and Mexico)17 have been estimated. Police
Drug-specific mortality (CW 5·1)
Drug-related mortality (CW 6·4)
Drug-specific damage (CW 4·1)
Drug-related damage (CW 4·1)
Dependence (CW 5·7)
Drug-specific impairment of mental functioning (CW 5·7)
Drug-related impairment of mental functioning (CW 5·7)
Loss of tangibles (CW 4·5)
Loss of relationships (CW 4·5)
Injury (CW 11·5)
Crime (CW 10·2)
Environmental damage (CW 3·8)
Family adversities (CW 8·9)
International damage (CW 3·8)
Economic cost (CW 12·8)
Community (CW 3·2)
Crack cocaine
Anabolic steroids
Overall harm score
55 54
27 26
20 19
15 15 14 13
11 910 9
Figure 4: Overall weighted scores for each of the drugs
The coloured bars indicate the part scores for each of the criteria. The key shows the normalised weight for each criterion. A higher weight indicates a larger diff erence
between the most harmful drug on the criterion and no harm. CW=cumulative weight. GHB=γ hydroxybutyric acid. LSD=lysergic acid diethylamide.
Articles Published online November 1, 2010 DOI:10.1016/S0140-6736(10)61462-6
records lend support to the eff ect of drug dealing on
communities and of alcohol-related crime.18 However,
data are not available for many of the criteria, so the
expert group approach is the best we can provide. The
many high correlations (of our overall results with those
of the Dutch addiction medicine expert group, and of
some of our input scores with objective data) provide
some evidence of the validity of our results.
The issue of the weightings is crucial since they aff ect
the overall scores. The weighting process is necessarily
based on judgment, so it is best done by a group of experts
working to consensus. Although the assessed weights
can be made public, they cannot be cross-validated with
objective data. However, the eff ect of varying the
weightings can be explored in the computer program
through sensitivity analysis. For example, we noted that it
would be necessary to increase the weight on drug-
specifi c mortality or on drug-related mortality by more
than 15 of 100 points before heroin displaced alcohol in
rst position of overall harm. A similarly large change in
the weight on drug-specifi c damage would be needed,
from about 4% to slightly more than 70%, for tobacco to
displace alcohol at fi rst position. And an increase in the
weight on harm to users from 46% to nearly 70% would
be necessary for crack cocaine to achieve the overall most
harmful position. Extensive sensitivity analyses on the
weights showed that this model is very stable; large
changes, or combinations of modest changes, are needed
to drive substantial shifts in the overall rankings of the
drugs. Future work will explore these weightings with
use of other groups—both expert panels and those from
the general public.
Limitations of this approach include the fact that we
scored only harms. All drugs have some benefi ts to the
user, at least initially, otherwise they would not be used,
but this eff ect might attenuate over time with tolerance
and withdrawal. Some drugs such as alcohol and tobacco
have commercial benefi ts to society in terms of providing
work and tax, which to some extent off set the harms and,
although less easy to measure, is also true of production
and dealing in illegal drugs.19 Many of the harms of drugs
are aff ected by their availability and legal status, which
varies across countries, so our results are not necessarily
applicable to countries with very diff erent legal and
cultural attitudes to drugs. Ideally, a model needs to
distinguish between the harms resulting directly from
drug use and those resulting from the control system for
that drug. Furthermore, they do not relate to drugs when
used for prescription purposes. Other issues to explore
further include building into the model an assessment of
polydrug use, and the eff ect of diff erent routes of
ingestion, patterns of use, and context.20 Finally, we
should note that a low score in our assessment does not
mean the drug is not harmful, since all drugs can be
harmful under specifi c circumstances.
In conclusion, we have used MCDA to analyse the
harms of a range of drugs in relation to the UK (panel 2).
Our fi ndings lend support to previous work in the
UK and the Netherlands, confi rming that the present
drug classifi cation systems have little relation to the
evidence of harm. They also accord with the conclusions
of previous expert reports11,18 that aggressively targeting
alcohol harms is a valid and necessary public
health strategy.
DJN designed and participated in the study. LAK participated in the
study. LDP participated in the running of the study and analysed data.
All authors wrote the report and responded to referees’ comments.
Confl icts of interest
DJN and LAK received travel expenses to attend the decision
conference meeting. LAK is a consultant to the Department of Health
and the EMCDDA. LDP is a director of Facilitations Limited, which
paid him a consulting fee because it was the company engaged by the
Centre for Crime and Justice Studies to run the study and analyse
the data.
This study is funded by the Centre for Crime and Justice Studies (UK).
Yuji Wu assisted with some of the data analyses.
1 Nutt D, King LA, Saulsbury W, Blakemore C. Development of a
rational scale to assess the harm of drugs of potential misuse.
Lancet 2007; 369: 1047–53.
2 Murphy PN, Britton J, Arnott D, et al. Assessing drug-related harm.
Lancet 2007; 369: 1856–57.
3 Dodgson J, Spackman M, Pearman A, Phillips L. Multi-criteria
analysis: a manual. London: Department of the Environment,
Transport and the Regions, 2000.
4 Morton A, Airoldi M, Phillips L. Nuclear risk management on
stage: the UK’s Committee on Radioactive Waste Management.
Risk Anal 2009; 29: 764–79.
Panel 2: Research in context
Systematic review
We analysed the data obtained from a multicriteria decision
analysis (MCDA) conference on drug harms. The harms were
assessed according to a new set of 16 criteria developed by
the Advisory Council on the Misuse of Drugs (the UK
Government committee on drug misuse). A panel of
drug-harm experts was convened to establish scores for
20 representative drugs that are relevant to the UK and which
span the range of potential harms and extent of use.
Participants scored the relative harms of each drug on each of
16 criteria, and then assessed criterion weights to ensure that
units of harm were equivalent across all criteria. Calculation
of weighted scores provided a composite score on two
dimensions, harm to the individual and harm to society, and
an overall weighted harm score.
These fi ndings lend support to earlier work from both UK and
Dutch expert committees on assessment of drug harms, and
show how the improved scoring and weighting approach of
MCDA increases the diff erentiation between the most and
least harmful drugs. On the basis of these data it is clear that
the present UK drug classifi cation system is not simply based
on considerations of harm.
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... According to the EU-CEG, there were a total of 4,934 tobacco or herbal smoking products on the market in the Czech Republic as of June 2021 (about 5,000 different smoking tobacco products, including about 490 brands of cigarettes). There is also a specific range such as cigars (2,723) and shisha tobacco (644) Analysing the harm caused by addictive substances is not easy and the methodology is widely debated (Nutt et al. 2010;Communities and Local Government 2009;Nutt et al. 2007;Murphy 2007;Best et al. 2003;Rhodes 2009;Van Amsterdam et al. 2010 (Hall et al. 1999), drug addiction (Anthony et al. 1997), effective dose-to-lethality ratios (Gable 2004), and drug toxicity profiles (Goldstein and Kalant 1990). 4 Drug-specific mortality (intrinsic lethality of a drug expressed as the ratio of the lethal dose to the standard dose. ...
... Prevalence of illegal substance use in the general population(Mravčík 2022b) Harm caused by substance use(Nutt et al. 2010) Trends in substance-impaired suicide rates 2017-2021 Suicidality as a direct consequence of substance intoxication SubstanceDimensions Threat Ambivalence of value content Preference for instrumental values (traits) in alcohol abstinence Preference values for alcohol abstinence Perceived threat of alcohol and users' terminal value preferences Preference for instrumental values (characteristics) when abusing tobacco, nicotine and related products Target preferences for abstinence from tobacco, nicotine and related products Perceived risk and value preferences of tobacco, nicotine and related products users Preference for instrumental values (properties) for abused drugs and medicines Target preferences for abstinence from drugs and medicines Perceived threat from medicines and medicinal products and the preferences of its users' values Preference for instrumental values (characteristics) for illegal substance use Target preferences for illegal substance use Exposure to illegal drugs and user value preferences ...
... ing to the categorisation used in the study "Drug harms in the UK"(Nutt et al. 2010). The diagram shows that harm is caused both to the user and to those around them in three domains: psychological, physical and social. ...
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The book presents the results of part of a broadly defined international Czech-Slovak interdisciplinary cross-sectional survey conducted before the Covid-19 pandemic (collection 2018–2019) and during the pandemic (collection 2020–2021). The first chapter introduces the reader to the broad context of substance use risks. Following this theoretical anchoring of the issues under study, the reader is presented in subsequent chapters with the results of a sociodemographic analysis of attitudes towards substance abuse, the results of an analysis of original measures of reflection on the risk of substance abuse in four domains that are key to the social functioning of each substance user: 1. Health and possible health risks associated with substance abuse. 2. Economic risks associated with substance abuse. 3. Social relationships, status, and ties in the local community and society. 4. The perceived threat along these four dimensions is analysed concerning the value preferences of respondents. The threat of addictive substances is strongly perceived, especially in the area of health, and media campaigns and established prevention programmes have been very successful in this respect. We are led to this interpretation by the fact that respondents feel most threatened by smoking in the health dimension but do not feel a similar threat when abusing illicit drugs. Threats in the economic dimension are similar to those in the health dimension and are felt most strongly for tobacco abuse. Again, respondents with drug abuse perceive the lowest degree of threat in this domain. The area of family life is perceived as threatening, especially for alcohol abuse. The explanation seems logical. Alcohol becomes a health risk only gradually with prolonged excessive consumption. However, before it destroys the body, it destroys the personality (many respondents see/know of families that have broken up because of alcohol). Tobacco, although it is also a legal addictive substance and its social tolerance is high, affects a person precisely in the area of physical health but has little effect on mental health. Thus, tobacco does not pose a direct threat to the family, i.e. it does not destroy the family relationally. The other drugs have a negative connotation (with perhaps the minor exception of marijuana), and their role in devastating health and the family is well known, both as a consequence and as a cause. While respondents recognise a substantial risk in the area of family relationships, this threat is not seen in the social context. It does not cause social exclusion as strongly, nor does it very often lead to a loss of social status. Drinking alcohol and smoking, in particular, appears to be socially acceptable and part of standard social integration. The results show that values that refer to a desire for adventure and varied experiences (active and exciting life, courageous/brave, open/receptive, creative) are positively associated with substance abuse. This connection is in line with all assumptions about the value orientations of people with drug abuse, where the drug symbolises a new journey, an uncharted adventure, fulfilling the need to break away from stereotypes, a rebellion against stereotypes, and the dull greyness of everyday life. Logically, in line with values that saturate the experience of adventure and discovering the new, the unknown, the group of respondents with the abuse of illegal drugs and tobacco, nicotine, and related products also cherishes the values that lead to an escape from norms (freedom, equality). A correlation can also be traced to the desire for pleasure, joy, and happiness. The positive effects of drugs, as they are generally described and understood, directly promise the fulfilment of these values. A specific category is the value of a comfortable life, which is highly valued by people abusing illicit substances. Illicit drugs are a way to escape from responsibilities; they symbolise carelessness. All of these values are highly preferred by abusers and, conversely, rated low by people who have had problems with the substance in the past but are currently abstinent. Thus, value preferences are dominated by a preference for other values. A significant challenge for interventions in the field of social pedagogy is the positive correlation of the value of friendship/friendship with abstinence from tobacco, nicotine, and related products. It is again confirmed that the problem in Czech society is not only a high tolerance for abusive behaviour but that abusive behaviour is a social norm. The quest for social bonding leads to this abusive behaviour. The analysis of value preferences thus again confirms the initial assumption that abusing legal substances is a social issue, a way of making contacts, and a way for people to get closer to each other. Primary prevention, as currently conceived, does not seem to be sufficiently compelling. The authors of the book take the view that its effectiveness can only be increased by integrating a values-based context into prevention programmes and ensuring that prevention does not only aim to prevent abuse but also has an educational effect. Indeed, as the research presented here shows, some values are intensely reinforced in respondents who have managed to stop their problematic substance use and are abstinent. They cherish these values even more than people who avoid these substances for life. On the other hand, there are also values that former substance users significantly less prefer compared to current users and the general population. Thus, reinforcing these value preferences as part of secondary prevention is an appropriate way to bring about lasting behavioural and attitudinal change. The design of specific prevention programmes and their future implementation will require a more in-depth analysis of each value in the context of the social functioning of at-risk groups. This analysis, its implications, and, above all, the design of prevention programmes dedicated to the effective reinforcement of values that influence attitudes towards substance abuse will be one of the critical tasks of social work and social pedagogy.
... This definition is unhelpfully non-specific in both scientific and legal terms, and the Act itself does not provide further guidance or examples. Controversially, alcohol and tobacco were exempted from the Act, as indeed they were previously not included under the Misuses of Drugs Act 1971, despite expert opinion showing that alcohol dependence was the most prevalent substance use disorder globally with 100.4 million estimated cases in 2016 (GBD, 2016) and alcohol being ranked as the most harmful drug in the UK (Nutt et al., 2010), while tobacco consumption accounted for 7.7 million deaths worldwide in 2019 being the leading risk factor for death among males (Drug Science, 2022; Reitsma et al., 2021). ...
... The 'technical' part refers to the model itself. This is based on multi-criteria decision analysis, first introduced by Keeney and Raiffa (1976), and now an accepted methodology for dealing with decisions that are characterized by multiple objectives and uncertainty, which in this case takes into consideration risks for the user and others The multi-criteria decision analysis (MCDA) model developed in 2010 enabled a group of diverse experts to evaluate the harm of 20 psychoactive drugs on 16 criteria of harms (Nutt et al., 2010). Note neither nitrous oxide nor poppers were included in this review as the decision making group considered them to be responsible for little harm and so of less interest than the twenty substances that were assessed. ...
... The names of the drugs that were judged most and least harmful (Nutt et al., 2010) are shown in Table 3, along with the final weighted scores for N 2 O and poppers. Most of the scores for N 2 O and poppers are low, in single digits. ...
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The recent surge in recreational (non-medical) use of nitrous oxide (N2O, also known as ‘laughing gas’) often by inhaling it from balloons, has attracted the attention of some politicians with calls to control its possession under the United Kingdom (UK) Misuse of Drugs Act 1971 (currently selling, but not possession, for recreational use is controlled under the Psychoactive Substances Act 2016). Meanwhile, the recreational use of nitric monoxide (NO) as delivered by alkyl nitrites, also known as ‘poppers’ has also raised concerns, but unlike N2O, its use was not controlled under the 2016 Act. To inform future-decision making processes and ensure that any such decisions are based on the best evidence, Drug Science conducted a Multi-Criteria Decision Analysis (MCDA) about N2O and poppers to compare the overall harms of these two drugs to the harms of 20 drugs previously evaluated and published by Nutt et al. The group assessed harm scores for N2O and poppers on the original 16 harm criteria using the associated 0 to 100 scales, on each of which 100 had been assigned to the most harmful drug and zero to the least harmful, though that often meant no harm. On the overall harm scale, N2O scored 6, just above magic mushrooms (psilocybin) while ‘poppers’ scored 5. Together these are the three lowest drugs on the overall harm scale. Although their overall scores are similar, the reasons behind the ratings differ. Nitrous oxide was considered more harmful than poppers for Dependence, Environmental Damage, Drug Related Relative Impairment of Mental Functioning, and Family Adversities, while poppers are more harmful than N2O for Injury, Drug Related Damage, Economic Cost, and Drug Related Mortality. When assessing the risk different substances may hold when making policy decisions, it is important to acknowledge the relative contribution of these diverse harms within different domains.
... We therefore only considered the data representing all volcanoes under the same conditions, and we used as many objectively measurable criteria as possible to minimise human subjectivity and inconsistency. Here, we decided on a multicriteria decision analysis (MCDA), which is a method frequently used to aid in prioritising and decision-making for complex and multifaceted problems across many scientific disciplines -for example, in medical sciences evaluating the impact of drugs (Nutt et al., 2010), in Earth sciences assisting in the management of nuclear waste disposal sites (Morton et al., 2009), or in hazard evaluations of flood-prone sites (Fernández and Lutz, 2010;Rahmati et al., 2016;Toosi et al., 2019). Our MCDA system uses weighted point scores based on five major factors to influence our final ranking. ...
... Ewert et al., 2018), which is also what we do in our ranking. MCDAs in other fields often have more quantitative scales such as 0-9 points (Fernández and Lutz, 2010;Rahmati et al., 2016) or 0-100 (Nutt et al., 2010), but the score systems are still assigned arbitrarily. Thus, all these approaches and our ranking presented here use some degree of subjective judgement, as not all factors directly translate into an empirical hazard or risk value. ...
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Tsunamis caused by large volcanic eruptions and flanks collapsing into the sea are major hazards for nearby coastal regions. They often occur with little precursory activity and are thus challenging to detect in a timely manner. This makes the pre-emptive identification of volcanoes prone to causing tsunamis particularly important, as it allows for better hazard assessment and denser monitoring in these areas. Here, we present a catalogue of potentially tsunamigenic volcanoes in Southeast Asia and rank these volcanoes by their tsunami hazard. The ranking is based on a multicriteria decision analysis (MCDA) composed of five individually weighted factors impacting flank stability and tsunami hazard. The data are sourced from geological databases, remote sensing data, historical volcano-induced tsunami records, and our topographic analyses, mainly considering the eruptive and tsunami history, elevation relative to the distance from the sea, flank steepness, hydrothermal alteration, and vegetation coverage. Out of 131 analysed volcanoes, we found 19 with particularly high tsunamigenic hazard potential in Indonesia (Anak Krakatau, Batu Tara, Iliwerung, Gamalama, Sangeang Api, Karangetang, Sirung, Wetar, Nila, Ruang, Serua) and Papua New Guinea (Kadovar, Ritter Island, Rabaul, Manam, Langila, Ulawun, Bam) but also in the Philippines (Didicas). While some of these volcanoes, such as Anak Krakatau, are well known for their deadly tsunamis, many others on this list are lesser known and monitored. We further performed tsunami travel time modelling on these high-hazard volcanoes, which indicates that future events could affect large coastal areas in a short time. This highlights the importance of individual tsunami hazard assessment for these volcanoes, the importance of dedicated volcanological monitoring, and the need for increased preparedness on the potentially affected coasts.
... Many compounds have been criminalized and effectively excluded from research without an understanding of their pharmacology and toxicology (Nutt et al., 2013). Recent studies have demonstrated that the degree of restriction for illegal drugs does not correlate with their risk of harm, and there is no formalized process for reviewing these determinations at the national or international level (Nutt et al., 2010(Nutt et al., , 2013. Current laws, not based on evidence, impede research by onerous storage and security requirements, difficulty in obtaining funding, and the near impossibility of actually obtaining restricted compounds without having them synthetically produced at great cost (Nutt et al., 2013). ...
... We do our patients a disservice by not understanding and appropriately investigating compounds with potential therapeutic value because of their prior controversial associations and on their capacity for misuse. More flexibility in research on such compounds and a more scientifically rigorous basis for classifying and restricting drugs based on their potential physical, social, and psychiatric harms may pave the road for delineation of novel therapeutic and mechanistic data from previously unavailable compounds (Nutt et al., 2010). The work presented in this issue by Griffiths et al. and Ross et al., beyond its obvious implications for patients with comorbid advanced cancer and depression and anxiety, serves as a model for revisiting criminalized compounds of interest in a safe, ethical way. ...
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... Results from the drug discrimination test reveal that 5-HT2AR agonists produce a unique profile of interoceptive cues that the animals can discriminate from other pharmacological effects (Fantegrossi et al., 2008;Hanks and González-Maeso, 2013;Nichols, 2016 (Nutt et al., 2010), such as LSD and psilocybin (Carhart-Harris and Goodwin, 2017;Nichols, 2016), these compounds are not necessarily the most optimal future drug candidates, when considering both therapeutic efficacy and long-term safety. For example, the active metabolite of psilocybin, psilocin, has ~20-fold higher binding affinity to the 5-HT2BR compared to the 5-HT2AR , and activation of 5-HT2BRs can potentially lead to heart This document is the author copy of the peer-reviewed version before copyediting. ...
Psychedelic-assisted psychotherapy holds great promise in the treatment of mental health disorders. Research into 5-hydroxytryptamine 2A receptor (5-HT2AR) agonist psychedelic compounds has increased dramatically over the past two decades. In humans, these compounds produce drastic effects on consciousness, and their therapeutic potential relates to changes in the processing of emotional, social, and self-referential information. The use of animal behavior to study psychedelics is under debate, and this review provides a critical perspective on the translational value of animal behavior studies in psychedelic research. Acute activation of 5-HT2ARs produces head twitches and unique discriminative cues, disrupts sensorimotor gating, and stimulates motor activity while inhibiting exploration in rodents. The acute treatment with psychedelics shows discrepant results in conventional rodent tests of depression-like behaviors but generally induces anxiolytic-like effects and inhibits repetitive behavior in rodents. Psychedelics impair waiting impulsivity but show discrepant effects in other tests of cognitive function. Tests of social interaction also show conflicting results. Effects on measures of time perception depend on the experimental schedule. Lasting or delayed effects of psychedelics in rodent tests related to different behavioral domains appear to be rather sensitive to changes in experimental protocols. Studying the effects of psychedelics on animal behaviors of relevance to effects on psychiatric symptoms in humans, assessing lasting effects, publishing negative findings, and relating behaviors in rodents and humans to other more translatable readouts, such as neuroplastic changes, will improve the translational value of animal behavioral studies in psychedelic research. SIGNIFICANCE STATEMENT: Psychedelics like LSD and psilocybin have received immense interest as potential new treatments of psychiatric disorders. Psychedelics change high-order consciousness in humans, and there is debate about the use of animal behavior studies to investigate these compounds. This review provides an overview of the behavioral effects of 5-HT2AR agonist psychedelics in laboratory animals and discusses the translatability of the effects in animals to effects in humans. Possible ways to improve the utility of animal behavior in psychedelic research are discussed.
... While undeniably self-serving, the techniques of neutralization presented by interviewees should not necessarily be cynically interpreted. While it falls outside the scope of this research to assess either the validity of the rationalizations presented above or the relative harmfulness of online vs offline drug trading (see Martin 2014a;Aldridge et al. 2018) many of the claims offered by interviewees are broadly consistent with a range of research that differentiates between drugs in terms of their potential to result in harms both to users and to broader society (Nutt et al. 2010), as well as the 'harm maximization' and hugely deleterious effects associated with global drug prohibition (Werb et al. 2011). ...
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Prolonged periods in space have potentially deleterious physiological and psychological effects. Ensuring the physical health and mental well-being of astronauts will inevitably supersede the need for technological innovation, as the major challenge in long-duration space travel. We propose a role for psychedelics (psychoactive fungal, plant, and animal molecules that cause alterations in perception, mood, behavior, and consciousness) and in particular psychedelic mushrooms to facilitate extended sojourns in space. Psychedelics research is in the midst of a renaissance and psychedelics are being explored not only for their therapeutic potential in psychiatry but also for their ability to promote neuroplasticity, modulate the immune system and reduce inflammation. Psychedelics may be to long-duration space travel in the 21st century, what citrus fruits were to long-distance sea travel in the 18th century-breakthrough and facilitatory. The human intergalactic experience is just beginning and it would be wise to consider the benefits of ensuring that astronauts undertaking potentially perilous space voyages benefit from our planet's rich psychedelic heritage. There is also some justification for considering the application of psychedelics in the processing and integration of the profound and spiritual experience of deep space travel.
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Studying prevalence of Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) drug dependence among Americans 15–54 yrs old, the authors found about 1 in 4 (24%) had a history of tobacco dependence; about 1 in 7 (14%) had a history of alcohol dependence, and about 1 in 13 (7.5%) had a history of dependence on an inhalant or controlled drug. About one third of tobacco smokers had developed tobacco dependence and about 15% of drinkers had become alcohol dependent. Among users of the other drugs, about 15% had become dependent. Many more Americans age 15–54 have been affected by dependence on psychoactive substances than by other psychiatric disturbances now accorded a higher priority in mental health service delivery systems, prevention, and sponsored research programs. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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How risky is heroin? How risky is ecstasy, cocaine or cannabis? Well it depends on who you talk to, what position they are coming from and what agenda they want to pursue. There is, therefore, a great deal of variance in the understanding and propagation of the dangers attached to illicit drug use. Too little of this variance however is based on reliable and appropriate risk appraisal and too much is based on historical attribution and emotive reasoning. As an assessment of prospective danger and the basis of ongoing and future policy, risk analysis and information pertaining to drug risks has got to be less subject to personal and emotional bias and more reliant on reasoned, comparative and reliable appraisal of the risks than at present. Although drugs control policy has always, in spirit at least, been strongly related to notions of dangerousness or risk it has not always (and it remains true today) been based on very sound analysis. In fact “proper” risk analysis has only really developed in the last thirty years or so and is, in many ways, still in its infancy (Renn, 1998). Despite this development however, risk assessment in relation to illicit drugs remains woefully defi-
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To determine the acute lethal toxicity of a range of psychoactive substances in terms of the dose customarily used as a single substance for non-medical purposes. A structured English-language literature search was conducted to identify experimental studies and clinical reports that documented human and non-human lethal doses of 20 abused substances that are distributed widely in Europe and North America. Four inclusion criteria were specified for the reports, and approximately 3000 relevant records were retrieved from search engines at Biosis, Science Citation Index, Google and the National Library of Medicine's Gateway. In order to account for different drug potencies, a 'safety ratio' was computed for each substance by comparing its reported acute lethal dose with the dose most commonly used for non-medical purposes. The majority of published reports of acute lethal toxicity indicate that the decedent used a co-intoxicant (most often alcohol). The calculated safety ratios varied between substances by more than a factor of 100. Intravenous heroin appeared to have the greatest direct physiological toxicity; several hallucinogens appeared to have the least direct physiological toxicity. Despite residual uncertainties, the substantial difference in safety ratios suggests that abused substances can be rank-ordered on the basis of their potential acute lethality.
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Drug misuse and abuse are major health problems. Harmful drugs are regulated according to classification systems that purport to relate to the harms and risks of each drug. However, the methodology and processes underlying classification systems are generally neither specified nor transparent, which reduces confidence in their accuracy and undermines health education messages. We developed and explored the feasibility of the use of a nine-category matrix of harm, with an expert delphic procedure, to assess the harms of a range of illicit drugs in an evidence-based fashion. We also included five legal drugs of misuse (alcohol, khat, solvents, alkyl nitrites, and tobacco) and one that has since been classified (ketamine) for reference. The process proved practicable, and yielded roughly similar scores and rankings of drug harm when used by two separate groups of experts. The ranking of drugs produced by our assessment of harm differed from those used by current regulatory systems. Our methodology offers a systematic framework and process that could be used by national and international regulatory bodies to assess the harm of current and future drugs of abuse.
Studying prevalence of Diagnostic and Statistical Manual (3rd ed., rev., American Psychiatric Association, 1987) drug dependence among Americans 15-54 years old, we found about 1 in 4 (24%) had a history of tobacco dependence; about 1 in 7 (14%) had a history of alcohol dependence; and about 1 in 13 (7.5%) had a history of dependence on an inhalant or controlled drug. About one third of tobacco smokers had developed tobacco dependence and about 15% of drinkers had become alcohol dependent. Among users of the other drugs, about 15% had become dependent. Many more Americans age 15-54 have been affected by dependence on psychoactive substances than by other psychiatric disturbances now accorded a higher priority in mental health service delivery systems, prevention, and sponsored research programs.
Drug policy makers continuously face a changing pattern of drug use, i.e. new drugs appear on the market, the popularity of certain drugs changes or drugs are used in another way or another combination. For legislative purposes, drugs have mostly been classified according to their addictive potency. Such classifications, however, lack a scientific basis. The present study describes the results of a risk assessment study where 19 recreational drugs (17 illicit drugs plus alcohol and tobacco) used in the Netherlands have been ranked by a Dutch expert panel according to their harm based on the scientific state of the art. The study applies a similar approach as recently applied by Nutt et al. [Lancet 2007;369:1047-1053], so that the results of both studies could be compared. The harm indicators scored are acute and chronic toxicity, addictive potency and social harm. The aim of this study is to evaluate whether the legal classification of drugs in the Netherlands corresponds with the ranking of the drugs according to their science-based ranking of harm. Based on the results, recommendations are formulated about the legal classification of recreational drugs at national and international level which serves a rational approach for drug control.
To determine the lethal toxicity of five commonly-used illicit substances by relating the number of associated deaths to their availability. An index of toxicity was calculated for each of five drugs [heroin, cocaine/crack, ecstasy (MDMA), amphetamine and cannabis] as the ratio of the number of deaths associated with that substance to its availability in the period 2003-2007. Three separate proxy measures of availability were used (number of users as determined by household surveys, number of seizures by law enforcement agencies and estimates of the market size). All data are related to England and Wales only. There was a broad correlation between all three denominators of availability. Not unexpectedly, heroin and cannabis showed, respectively, the highest and lowest toxicities. The index of fatal toxicity of MDMA was close to that of amphetamine and cocaine/crack. There was a rank correlation between this index and other measures of lethal toxicity based on safety ratios. These results are contrary to widely-held public views of the relative fatal toxicity of MDMA.
In 2003, the UK government set up a broad-based Committee on radioactive waste management (CoRWM) to look at the UK's policy on radioactive waste management with a view to jumpstarting a stalled policy process. The committee's brief was to come up with a set of recommendations that would protect the public and the environment, and be capable of inspiring public confidence. After consulting widely with the public and stakeholders, and drawing on advice from scientists and other experts, CoRWM arrived at a remarkably well-received set of recommendations. On the basis of our experiences of working on CoRWM's multi-criteria decision analysis of different management options, study of CoRWM documentation, and interviews with committee members, we describe the explicit and implicit principles that guided CoRWM. We also give an account of the process by which CoRWM arrived at its conclusions, covering four phases: framing, shortlisting, option assessment, and integration; and four cross-cutting activities: public and stakeholder engagement (PSE), science and engineering input, ethics and social science input, and learning from overseas practice. We finish by outlining some of the key developments in the UK's radioactive waste management process, which followed on from the publication of CoRWM's report, and present our reflections for the benefit of the risk and decision analysts of future committees that, like CoRWM, are charged with recommending to government on the management of technically complex and risky technologies, drawing on extensive public and stakeholder consultation.