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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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... It is critical to appreciate the distinction between psychedelics used in recreational contexts versus pharmaceuticalgrade psychedelics used in approved controlled clinical settings. Psychedelics overall have a low potential for addiction and harm [17,18]. The large majority of instances of harm in recreational settings involve adulterants, substances taken concomitantly [19], or other unsafe practices [20][21][22][23]. ...
... Addiction Psychedelics, to include MDMA, psilocybin, and LSD, have a low potential for dependence and harm (Fig. 5) [17,18]. When administered in a therapeutic context with trained Content courtesy of Springer Nature, terms of use apply. ...
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Purpose of Review This review discusses the current and projected landscape of psychedelic-assisted therapy (PAT), with a focus on clinical, legal, and implementation considerations in Department of Defense (DoD) and Department of Veterans Affairs (VA) healthcare systems. Recent Findings 3,4-Methylenedioxymethamphetamine (MDMA)- and psilocybin-assisted therapy have shown promising outcomes in efficacy, safety, tolerability, and durability for PTSD and depression, respectively. MDMA-assisted therapy is already approved by the Food and Drug Administration (FDA) on an Expanded Access (“compassionate use”) basis for PTSD, with full approval projected for 2024. Psilocybin-assisted therapy is projected to be FDA-approved for depression soon thereafter. Other psychedelics are in earlier stages of development. The VA is currently conducting PAT clinical trials. Summary Although there are clear legal pathways for the VA and DoD to conduct PAT trials, a number of implementation barriers exist, such as the very high number of clinical hours necessary to treat each patient, resource requirements to support treatment infrastructure, military-specific considerations, and the high level of evidence necessary for PAT to be recommended in clinical practice guidelines. Ongoing considerations are whether and how PAT will be made available to VA and DoD beneficiaries, feasibility and cost-effectiveness, and ethical safeguards that must be implemented to prioritize access to PAT given the likelihood of extremely limited initial availability. However, with imminent FDA approval of PATs and considerable national interest in these treatments, DoD and VA policymakers must be prepared with clearly delineated policies and plans for how these healthcare systems will approach PAT.
... The problematic use of alcohol and other intoxicants causes our society numerous individual harms, human suffering for significant others and the immediate environment and a burden on public institutions [1,2]. In society the costs of substance abuse are considerable in health care, pensions and sickness benefits, in addition to which the costs incurred by social services and social security through the negative effects of alcohol consumption alone amounted in Finland to some 230-260 million euros in 2016 [3]. ...
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Problematic substance use causes significant harm to individuals, communities and society as a whole. Nowadays solutions to bring substance abuse under control and provide help are being sought from digital tools. This literature review scrutinizes digital applications and internet-based self-care programs from the perspective of providing services. The purpose is to ascertain how the preconditions for the implementation of self-care are understood in studies addressing digital tools for the substance abuse sector. The question posed concerns what features in digital applications supporting control of substance abuse, their users and operating environment influence the implementation of self-care. The research method is an integrative literature review. The data consist of peer-reviewed scientific publications from the period 2012–2022. Data were gathered from two databases (ProQuest Central, PubMed). The final corpus comprises 18 research articles. The analytical frame of reference is the definition by El-Osta and others of four main dimensions of self-care. The findings suggest that factors pertaining to applications in the implementation of self-care are the technical usability of the service, the option for anonymity, variation in content, active reminders and application feedback, gamification and ability to identify with the user. Factors pertaining to the users, in addition to age and gender, are mode of substance abuse, duration of using history, severity of the problem, readiness for change, possible concurrent diagnoses, ability to process own feelings, social relations and digital literacy. Factors pertaining to the operating environment are legislation governing substance abuse, national intoxicant culture, stigma attached to substance abuse treatment, availability of support outside the application and the pandemic situation restricting face-to-face interaction. The diverse nature of the group of individuals with problematic substance use will in the future increase the need for user profiling and more individualized tailoring of application content in keeping with their life situations and stages of recovery.
... Overall, these substances appear less harmful for individuals and society when compared to alcohol, benzodiazepines, opioids, or other psychoactive drugs, and risks can be minimized with precautions related to usage, dosing, preparation, context, and supervision (Belouin and Henningfield 2018;Belouin et al. 2022;Nutt, King, and Phillips 2010;Johnson, Richards, and Griffiths 2008;Schlag et al. 2022). In fact, lifetime use of MDMA, LSD, or psilocybin appears to be associated with lower, not higher, rates of certain proxies for mental illness (Jones and Nock 2022;Krebs and Johansen 2013;Sexton, Nichols, and Hendricks 2020). ...
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As individuals and communities around the world confront mounting physical, psychological, and social threats, three complimentary mind-body-spirit pathways toward health, wellbeing, and human flourishing remain underappreciated within conventional practice among the biomedical, public health, and policy communities. This paper reviews literature on psychedelic science, contemplative practices, and Indigenous and other traditional knowledge systems to make the case that combining them in integrative models of care delivered through community-based approaches backed by strong and accountable health systems could prove transformative for global health. Both contemplative practices and certain psychedelic substances reliably induce self-transcendent experiences that can generate positive effects on health, well-being, and prosocial behavior, and combining them appears to have synergistic effects. Traditional knowledge systems can be rich sources of ethnobotanical expertise and repertoires of time-tested practices. A decolonized agenda for psychedelic research and practice involves engaging with the stewards of such traditional knowledges in collaborative ways to codevelop evidence-based models of integrative care accessible to the members of these very same communities. Going forward, health systems could consider Indigenous and other traditional healers or spiritual guides as stakeholders in the design, implementation, and evaluation of community-based approaches for safely scaling up access to effective psychedelic treatments.
... Moreover, the enhancement of plasticity is known to account for the endurable and fast-acting effects of ketamine when compared to other antidepressants (Casarotto et al., 2021). In this regard, the effects of ketamine and DMT on plasticity are comparable (Ly et al., 2018); however, while psychedelics do not seem to have addictive potential, ketamine does (Nutt et al., 2010;Dos Santos et al., 2018). Finally, DMT and other psychedelic tryptamines are known to have anti-inflammatory, immunomodulatory, and tissue-protective capabilities (Szabo, 2015); when combined to their plastogenic properties, these effects render these as promising drugs for the treatment of neurodegenerative disorders (Kozlowska et al., 2022). ...
... Fabi et al. (2014) and Mammone et al. (2014). These indicators are based on individual drug use frequency data and expert rankings of harms related to various "classical" substances, proposed by van Amsterdam et al. (2010) and Nutt et al. (2010). They allow the estimation of risk profiles for selected groups of individuals and comparisons, both over time and between populations. ...
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Poly-drug use is becoming increasingly common, in particular in young user groups. Classical single drug use indicators are not adequate to measure the combined possible harms of such patterns of use, while more complex indicators can summarize the total effects. One set of such indicators is used in this paper, based on individual frequency of use data and expert evaluations of single substance harms of various types. The indicators are applied to a set of Italian data relating to subjects who use psychotropic substances in nightlife, collected as part of the Eranid-Alama project. It is shown that the use of these poly-drug use indicators can be useful for characterizing high-risk subgroups of users and for studying associations between drug use and concomitant variables. In general, these indicators are also adequate for comparisons between different user groups and populations in various countries. An original point addressed in this study for the first time is the classification of new psychotropic substances (NPS) of interest for the survey, in collaboration with specific experts.
... A multi-criteria analysis of psychoactive substances (Nutt, King, andPhillips 2010, 1561) found heroin to be second to alcohol as contributing to the largest amount of overall physical and social harm to individuals and society in the United Kingdom. The health burden of opioids, of which heroin is the most widely used (UNODC 2022a, 16), is monitored in many countries. ...
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The City of Tshwane and University of Pretoria’s Community Oriented Substance Use Programme (COSUP) is an applied research intervention to address drug use-related harms in the city by using a harm reduction community-oriented primary care approach. This is a study of stakeholder perceptions of South Africa’s first publicly funded community-based harm reduction programme. In late 2021, purposively sampled respondents were surveyed using a cross-sectional survey. Electronically captured data were collected on respondent demographic characteristics, familiarity with COSUP and perceptions of COSUP’s effect on service users’ well-being, access to drug use services, family relationships, community integration, and on effective approaches to managing drug use. Frequencies and proportions were analysed as a total and by the degree of familiarity with COSUP, using descriptive statistics. Overall, 338 (93.1%) of the 363 stakeholders who consented to participate in the study had some familiarity with COSUP. Socio-demographically, 68.1% were female and over half (52.4%) were aged between 25–39 years. Most (70–80%) thought COSUP improved client well-being, family relationships and community re-integration. Most (80–84%) perceived COSUP to have increased service provider willingness to support people who use drugs, improved stakeholder networking and raised awareness of drug-related services. Most (76%) considered harm reduction to be the best approach to manage harmful drug use in the city. Stakeholders exposed to the work of COSUP perceive the intervention to be beneficial for individuals, families and service-providing organisations. Most favour a harm reduction approach to drug use and believe COSUP should be sustained and expanded.
... Alcohol has been considered the most harmful drug passing heroin and crack cocaine (Nutt et al., 2010). Globally, alcohol use disorders are the most prevalent substance use disorders with over 100 million cases estimated annually (GBD 2016 Alcohol andDrug Use Collaborators, 2018). ...
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Background: Alcohol use is among the topmost public health risk factors. There is a dearth of evidence on the broader impact of alcohol use on society, especially, for lower-middle-income countries like India. We retrospectively studied the economic burden of alcohol use and compared it with revenue from excise taxes on alcohol sales for India and its states in 2019. Methods: For estimating the overall alcohol-attributable disease burden, disability-adjusted life-years or DALYs for India and its 30 states were extracted for all causes, all age groups, and both sexes with alcohol use as a risk factor from the Global Burden of Disease 2019 Study. Economic burden was calculated by the value of life-year (VLY) or full-income approach. National and state-level (top 10 revenue-earning states) data on excise taxes on alcohol sales were acquired from the Reserve Bank of India. Net losses were assessed by subtracting the revenue from the economic burden. All values are in Indian rupees (INR). Sensitivity analysis was conducted using different discount rates (0%, 3%, and 7%) for VLY values while uncertainty was propagated using 95% uncertainty intervals (UIs for DALYs. Results: The economic burden of alcohol use in India was 6.2 (95% UI: 4.8, 7.8) trillion INR in 2019. State-level burden varied from 7.3 (4.7, 10.4) billion INR in Mizoram to 1.1 (0.8, 1.4) trillion INR in Maharashtra. Nationally, revenue was 1.8 trillion INR depicting a net loss of 4.4 (3.1, 6.0) trillion. Net loss was largest in Maharashtra and smallest in Telangana. Sensitivity analyses confirmed that all ten states depicted losses in the case of a 3% discount rate, while five and seven states showed losses at 0% and 7% discount rates. Conclusion: These are novel subnational estimates depicting annual net losses due to alcohol use in India with direct policy implications to disincentivize alcohol sales and raise taxes to an adequate level.
... Le champ de recherche des addictions en général, peut être perçu comme moins prioritaire que celui de la psychiatrie et, au sein même du champ des addictions, celui de l'alcool peut être perçu comme moins prioritaire comparativement par exemple aux autres substances voire aux addictions sans substances. L'alcool est pourtant la drogue qui crée le plus de dommages pour le consommateur (avec l'héroïne, le crack et la métamphétamine), son entourage et la société (14). La problématique de l'alcool est en proie à la fois au lobbying des industriels et des décideurs politiques qui ont encore une représentation beaucoup trop positive de l'alcool en France et pour qui l'alcool est un enjeu beaucoup plus économique ou électoral que de santé publique. ...
The fight against the health and social burden requires a global action plan in which research must play an important role. An inventory of alcohol research in France was conducted based on a bibliometric study of publications identified on the Web of Science over the period 2015-2020. France co-authored ≈4% of the corpus of global article production amounting to 25,311 titles reported by the query, placing it 8th in the world ranking. The temporal evolution of production over the period 2015-2020 in France is relatively constant. The mapping of alcohol research in France is characterized by a particular interest in epidemiology, toxicology, and translational studies in the field of neuroscience. France shares similarities with many countries in the organization of research (themes) but also has certain specificities, such as toxicology, which is more visible. It is also characterized by a strong delineation between basic and clinical research. The new opportunities for national organization, such as the creation of the national network of research in alcohology REUNIRA, and for financing, such as the fund for the fight against addiction, will certainly allow France to catch up internationally and to become more competitive in the field of alcohol research. However, the recognition of this theme as a national priority must certainly be improved in view of the colossal health and social damage in our country.
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Introduction: The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain limited. Methods: This prospective, longitudinal study comprised six sequential automated web-based surveys that collected data from adults planning to take psilocybin outside clinical research: at time of consent, 2 weeks before, the day before, 1–3 days after, 2–4 weeks after, and 2–3 months after psilocybin use. Results: A sample of 2,833 respondents completed all baseline assessments approximately 2 weeks before psilocybin use, 1,182 completed the 2–4 week post-use survey, and 657 completed the final follow-up survey 2–3 months after psilocybin use. Participants were primarily college-educated White men residing in the United States with a prior history of psychedelic use; mean age = 40 years. Participants primarily used dried psilocybin mushrooms (mean dose = 3.1 grams) for “self-exploration” purposes. Prospective longitudinal data collected before and after a planned psilocybin experience on average showed persisting reductions in anxiety, depression, and alcohol misuse, increased cognitive flexibility, emotion regulation, spiritual wellbeing, and extraversion, and reduced neuroticism and burnout after psilocybin use. However, a minority of participants (11% at 2–4 weeks and 7% at 2–3 months) reported persisting negative effects after psilocybin use (e.g., mood fluctuations, depressive symptoms). Discussion: Results from this study, the largest prospective survey of naturalistic psilocybin use to date, support the potential for psilocybin to produce lasting improvements in mental health symptoms and general wellbeing.
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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.