Best quotes:
[drugs &
crime not causal]
p.7 "the
distinction between drug associated effects and drug
caused effects. Here the distinction is between those
things that are associated with use of the drug
(social ostracism, criminal involvement) and those
directly caused by the drug (intoxication or
withdrawal)".
p.8 "One
particularly good example of this, as a
drug-associated effect, is the
relationship between drugs (heroin especially) and
crime, in which the complexity of the association
precludes a simplistic assertion that criminal
involvement is a danger of using drugs".
[powerful
organisations and social beliefs may distort data]
p.8 "a
powerful lobby, the alcohol industry, has an obvious
interest in minimising the number of deaths that are
attributed to alcohol. This political pressure acts
only to confound what is already a complex question
of aetiology".
p.8 "not
simply a question of monitoring but of political
decision-making, custom and practice and the dominant
belief models about the relationships between
events".
[prohibition
problems: data, discrimination & increased harm,
ineffective]
p.8 [if]
"prevalence of use is not known for certain
substances, then it is not possible to calculate the
incidence rate of the problem comparatively across
drugs. This is, in part, a result of the legal
situation in which many drugs are acquired illicitly
and so neither the total population of users nor the
total amount consumed can be readily estimated".
p.64 "there
is a fundamental dysjunction between the risks
associated with readily available legal drugs such as
tobacco and alcohol, and the illicit drugs, for which
a criminal justice component is inherent in the
profiling of dangers. Thus, while swallowing cocaine
may be generally less harmful than its injection,
this is not the case for the cocaine dealer who
swallows a package to avoid criminal detection".
p.32
"Cannabis availability: widely available across
the UK and internationally - no clear evidence of
both police or custom interventions on supply".
[drugs not
inherently dangerous]
p.48 "drugs
are not, of themselves, dangerous, with the risk
residing in the interaction between the substance,
the individual, the method of consumption and the
context of use".
[evidence that
cannabis is a safer intoxicant than alcohol]
- p.54 Table
15 chronic use
- p.55 Table
16 dependency - "cannabis is
rated as having the lowest
addictive potential on four of
the five criteria identified, with heroin
most strongly linked to reinforcement and
tolerance, tobacco to dependence and alcohol
to intoxication and withdrawal
severity".
- p.59 Table
18 deaths [in 1997 alcohol killed
30,000, tobacco 120,000, cannabis 13, heroin
255]
- p.60 Table
19 capture rates, dependency -
"What this would suggest is that tobacco
has the greatest potential for dependence
followed by heroin, then cocaine and alcohol.
Cannabis has the lowest
addictability of all the drugs
listed above".
[cannabis
self-medication & mental illness]
p.32
"Cannabis, Social Context/Setting:
- therapeutic
use
- possible
self-medication among psychiatric
patients".
[adolescents
reject value systems, independence cf drug
dependence]
p.61 "most
adolescents will go through a brief spell of
independence-assertion, called
adolescent-limited delinquency, during
which they will reject the value system of their
parents. This will lead to a period in which deviance
is valued, petty crime committed, where excessive
drinking is commonplace and where recreational drug
use occurs. In general, early adulthood signals the
end of this period, with employment and marriage the
most frequent catalysts".
[social factors
affecting drug use]
p.62
"background characteristics such as parental
drug use and family income, anti-social personality,
low intelligence and other factors that may increase
the risk of all kinds of lifetime problems".
p.62 "there
are also contemporary-contextual factors that
influence the decisions made here and now about
whether to use a drug. These may include
availability, opportunity, peer influence and
expectancies about what the drug will do".
p. 62 "the
dangerousness of an individual substance is difficult
to abstract from the context of its use a
context that is likely to include the individual
taking the drug, their expectations and beliefs about
the drug, the society that defines these beliefs and
the likelihood of sanctions and the state of the
individual at the time of consuming the drug".
p.64
"calculation of risk associated with any given
substance is a multi-faceted assessment embedded
within the typical use patterns and circumstances
commonly undertaken in particular societies. This is
partly a reflection on both societal and sub-cultural
beliefs and preferences, but will also be impacted
upon by the legal framework within which use occurs.
Thus, there is a fundamental dysjunction between the
risks associated with readily available legal drugs
such as tobacco and alcohol, and the illicit drugs,
for which a criminal justice component is inherent in
the profiling of dangers. Thus, while swallowing
cocaine may be generally less harmful than its
injection, this is not the case for the cocaine
dealer who swallows a package to avoid criminal
detection".
[perceived
benefits of drug use]
p.64 "the
current project does not attempt to enumerate the
positive effects that may be associated with
substance use, although it readily acknowledges that
part of the risk relates to this reinforcing quality
and the functionality of much substance
use".
[List of factors
affecting use:
p.5
- Chemical
properties
- Pattern of
use
- Context of
use
Scott p.6:
- the
behaviour of concern
- the
potential damage it causes
- the
probability of the behaviour
Brooks p.6:
Hall p.6:
- Individual
& social harm
- Prevalence
of use
- Relative
risk of harm
- Base rate
of harm
- Drug danger
= prevalence x likelihood
Jaffe p.6:
- Drug
properties
- Dose
- Route of
administration
- Setting
- Expectations
- Past
experiences
EMCCDA criteria
p.7:
Causes:
- Substance
properties (pharmacology &
toxicity)
- Social
factors (regulations, social norms)
- Methods
of use (patterns & context)
- Individual
characteristics (age, gender,
personality, genetics)
Consequences:
On
the user:
- Biological
(toxicity, dependence)
- Psychological
(functional impairment, effects on
personality)
- Behavioural
(neglect of social roles, violence
etc)
On
society:
- Micro-level:
Family (disruption, neglect &
violence)
- Meso-level:
Neighbourhood (public disorder &
insecurity)
- Macro-level:
Society as a whole (economic, health
& law)
Associations
(indirect consequences) p.8:
Measurements of
harm:
- Hospital
admissions
- Death
certificates
- Enforcement
statistics
- Surveys
Classification
used here p.13:
Acute
- Physical
- Psychological
- Social
Chronic
- Physical
- Psychological
- Dependence
- Social
Other factors
- Ingestion:
route, dose, purity
- Combination
use: other drug use
- Availability:
access & impact on use
- Law: itself
& its implementation
- Social
context: set, setting & class
- Age &
development: effect on harm of age of onset
& use
- Individual
vulnerability: susceptible individuals or
groups
- Incapacitation:
effect of imprisonment & treatment on use
Other:
- Individual:
BMI, expectation, dependence, social
exclusion, susceptibility to education,
development of individual responsibility
- Drug:
purity, quantity, frequency,
- Method of
use: injection, smoking, oral, nasal,
multiple drug use
- Context:
social attitudes & action (family, peers,
society), law & enforcement, education,
drug availability & advertising
Other good
quotes:
Introduction
drug effects
relate not only to chemical properties, but also to
the pattern and context of their use.
Definitions
[variables]
for such a
systematic analysis of danger to occur, it is
necessary to specify clearly the behaviour of
concern, the potential damage likely from that
behaviour and the probability that it will occur
under given circumstances. For Brooks (1984) the key
variables are the nature of the harm involved, its
magnitude, its imminence, its likelihood and its
frequency.
an appraisal of
the personal and public health impact of drug use
must account for the prevalence of use, the relative
risk of harm and the base rate of the adverse effect.
the variability
in hazard is a consequence of the drug, the dose, the
route of administration, the setting as well as the
expectations and experiences of the user.
[EMCDDA harm
assessment]
The European
Monitoring Centre for Drugs & Drug Addiction
(EMCDDA) published the guidelines for the risk
assessment of new synthetic drugs in 1999 which
includes the following taxonomies:
Sources of
hazard emanating from:
Properties of the substance (pharmacology &
toxicity)
Measures
of social control (regulatory policies & informal
norms)
Modalities of drug use (patterns & context of
use)
Individual characteristics of user (age gender
genetic personality)
Hazardous
effects of drugs:
On the
user:
Biological
(toxicity, dependence)
Psychological
(functional impairment, effects on personality)
Behavioural
(neglect of social roles, violence etc)
On the
social environment:
Family
micro level (disruption, neglect, violence)
Neighbourhood
& community meso level (public disorder
& insecurity)
Society at large
macro level (effects on the economy, public
health & judicial systems)
[association v
cause]
the distinction
between drug associated effects and drug caused
effects. Here the distinction is between those things
that are associated with use of the drug (social
ostracism, criminal involvement) and those directly
caused by the drug (intoxication or withdrawal).
Methodological
issues
[crime
associated with drugs, not directly caused]
To start with
the question of attribution of causality, it is
important to note that this applies to both
drug-associated effects and
drug-caused effects. One particularly
good example of this, as a
drug-associated effect, is the
relationship between drugs (heroin especially) and
crime, in which the complexity of the association
precludes a simplistic assertion that criminal
involvement is a danger of using drugs. On the other
hand, the recent court cases between tobacco
companies and cancer victims have highlighted the
problems of asserting causality for what would appear
a straight-forward health outcome. The problems are
twofold, the first relates to the number of potential
mediating variables, while the second is about our
confidence in asserting causal status to factors that
may be separated by
both time and
circumstances.
[Social bias]
One of the most
illuminating examples of this comes from the
death data associated with different
drugs. It relates not only to tobacco but also to
alcohol, where a powerful lobby, the alcohol
industry, has an obvious interest in minimising the
number of deaths that are attributed to alcohol. This
political pressure acts only to confound what is
already a complex question of aetiology a
person who dies from heart disease may well have had
their heart weakened by prolonged excessive drinking,
but may also have had a poor diet, little exercise
and a stressful lifestyle. In this way, alcohol may
well be an enabling condition rather than the single
causal determinant, complicating the question of
accounting. The recording of this death and its
inclusion in the statistics of alcohol dangers is
therefore not simply a question of monitoring but of
political decision-making, custom and practice and
the dominant belief models about the relationships
between events.
[prohibition
makes data collection difficult]
This is,
however, complicated by the way in which data are
recorded and information is gathered. Both Brooks
(1984) and Jaffe (1985) emphasised the issue of
frequency and prevalence of behaviour, yet this is
something around which we have limited information
for drug use, relying on epidemiological indicators
of prevalence for the baseline against which to
measure dangers. The problem this creates is that, if
the prevalence of an outcome, like treatment-seeking
or mortality is known for all drugs, yet prevalence
of use is not known for certain substances, then it
is not possible to calculate the incidence rate of
the problem comparatively across drugs. This is, in
part, a result of the legal situation in which many
drugs are acquired illicitly and so neither the total
population of users nor the total amount consumed can
be readily estimated.
Even for a legal
substance like alcohol, the quantity and prevalence
question cannot be readily calculated. Although it is
possible to record the total amount of alcohol sold
legally, this excludes illegally imported alcohol,
that consumed out of the country by UK citizens and
tells us little about patterns and prevalence of
alcohol consumption.
[data comparison
problems]
The issue of
comparability is not only a question of quality of
information (how reliable, representative,
up-to-date, etc) but of the type of indicators that
are measured across different drugs and by sources
with different objectives. Thus, two of the major
reference sources utilised in the literature analysis
for the project are Home Office statistics on drug
misuse (from which the mortality data have been
drawn) and the British Crime Survey, a national
household survey.
[top-down
reporting v bottom-up reporting]
The Home Office
data are based on reported cases, so they reflect the
system of recording and reporting used (changes in
these methods will alter the results obtained), as
well as the decision-making of those who present the
original information (is this a drug death? Does this
person qualify as an addict?).
In contrast, the
BCS is a voluntary participation survey in which the
data are compiled with the participants consent
and so is prey to the structural limitations inherent
in self-report. Thus while one source is restricted
by the methods of reporting and recording the other
is prey to the limitations and biases of self-report.
[caffeine is a
drug]
While a far
greater range of substances could have been
identified (including caffeine, khat and a number of
prescribed drugs that have been abused including
ketamine and dihydrocodeine), it was felt that it was
important to restrict the project to the drugs or
classes of drug that have the greatest impact on
health and social behaviour.
Results
Dangers
associated with use of the target substances were
initially categorised as chronic or acute, and
further classified under the main domains of physical
dangers (morbidity and mortality),
psychological/psychiatric dangers and
social/contextual negative effects.
When exploring
chronic effects, additional questions about the
addictiveness of each substance were
included. Participants were asked to describe this in
terms of how addictive the substance is, the
likelihood and circumstances of physical dependence,
as well as evidence of tolerance and withdrawal in
chronic users.
To reduce
abstraction, participants were also asked to consider
the factors that would mediate or moderate the main
effects of the substance. This was an attempt to
account for individual or group vulnerabilities and
dangers associated with the ways in which drugs were
used (such as the route of administration and popular
combinations). However, it is important to note that
there are also factors which may reduce the risk
associated with particular drugs and these were
included as moderating variables. The main framework
for this analysis is outlined in Box 2 opposite:
Box 2: Framework
for typology of dangerousness of drugs
- Acute
adverse effects dangers regardless of
frequency of use
Physical
Mortality
Morbidity
Psychological/psychiatric
Social
- Chronic
adverse effects dangers that are
cumulative with increased use
Physical
Mortality
Morbidity
Psychological/psychiatric
Dependence,
tolerance, withdrawal
Social
- Factors
that may mediate or moderate dangers
Aspects of ingestion (route of
administration, dose and purity)
Combination use (use with other drugs either
concurrently or consecutively)
Availability (how easily accessible is the
substance and how this impacts upon use)
Legal situation (both the law and its
implementation around use of the substance)
Social context (consequences of set, setting
& social milieu on the dangerousness)
Age & developmental issues (the likely
impact of age of onset & use on danger)
Individual vulnerability (particular
individuals or groups susceptible to specific
harms)
Incapacitation (the effect of imprisonment or
treatment on patterns of use including
the substitution of other drugs)
The
consideration of target drugs was then completed by
an estimation of the adequacy of the information and
the severity or likelihood of each risk factor for
each drug.
[alcohol tables
p.15-17 v cannabis p.30-32: cannabis safer
intoxicant]
[p.48:]
Strengths & limitations of tabular approach
[problems with
this analysis]
there are
fundamental limitations to this approach drugs
are not, of themselves, dangerous, with the risk
residing in the interaction between the substance,
the individual, the method of consumption and the
context of use. Among the main variables that will
shape risk relating to substance are amount and
purity, mediated by physiological and psychological
factors in the user (such as tolerance, expectation
and body mass), whether the drug is swallowed or
injected or whether it is used in a safe and familiar
environment.
it is not
possible to list all of these possible combinations
for each of the drugs (and more crucially for all of
the possible drug interactions).
[harm risk =
prevalence and likelihood]
In order to gain
an accurate picture of the potential dangers
associated with use of certain substances, we also
require a probability risk estimation to assess the
likelihood of an adverse effect occurring in any one
individual. This is the area in which prevalence of
use impacts upon the salience of certain types of
danger. Hall (1999) highlighted the fact that the
danger of a drug is related to both the prevalence of
its use and the likelihood of any harms.
An alternative
approach ranking the dangers
In their chapter
in "The Health Effects of Cannabis" (Kalant
et al, 1999), Hall, Room and Bondy undertake a
comparison of the health and psychological risks of
alcohol, cannabis, nicotine and opiates. They do
however point out a number of limitations with this
approach:
1. difficulties
in making causal inferences about the use of a drug
and adverse effects.
2. lack of
information about the extent or seriousness of drug
risks.
3. the
difficulties of making comparative appraisals of the
public health significance of identified risks.
4. the
recognition that different drugs are used in
different ways.
5. the
difficulty of predicting the consequences of changes
in either the prevalence of use of specific drugs or
in their routes of administration.
Their first
summary was of the "main adverse affects of
regular heavy use of the most harmful form of each
type of drug, as commonly used for non-medical
purposes" (p487). They did this firstly on the
basis of a literature review, differentiating between
important effects (in terms of number of heavy users
affected, marked as **) or those effects that are
less well established or less important numerically
(marked as *), see Table 15:
Table 15: Hall
et al (1999) assessment of comparative adverse
effects for heavy users of the most harmful form of
alcohol, nicotine, opiates and cannabis.
| |
Cannabis
|
Alcohol
|
Tobacco
|
Heroin
|
| Traffic and other
accidents |
*
|
**
|
|
*
|
| Violence and suicide |
|
**
|
|
|
| Overdose death |
|
*
|
|
**
|
| HIV and liver infections |
|
*
|
|
**
|
| Liver cirrhosis |
|
**
|
|
|
| Heart disease |
|
*
|
**
|
|
| Respiratory disease |
*
|
|
**
|
|
| Cancer |
*
|
*
|
**
|
|
| Mental illness |
*
|
**
|
|
|
| Dependence/addiction |
**
|
**
|
**
|
**
|
| Lasting effects on the
foetus |
*
|
**
|
*
|
*
|
A second tier of
assessment was carried out by asking two American
experts, Neal Benowitz and Jack Henningfield, to rate
the four substance types on five dimensions related
to the capacity of each drug to produce addiction and
casualties (Hilts, 1995). In Table 16 below, the
lower the score, the greater the likelihood
comparatively (ie 1 is the most likely to lead to
this problem and 4 the least).
Table 16:
Comparative ratings of the dependence potential of
cannabis, alcohol, tobacco and heroin (Hall et al,
1999).
| |
Cannabis
|
Alcohol
|
Tobacco
|
Heroin
|
| Presence and severity of
withdrawal symptoms |
4
|
1
|
3
|
2
|
| Reinforcement: Capacity to
get users to use again and again |
4
|
2
|
3
|
1
|
| Tolerance: How much more
needed by a regular user for the same effect |
4
|
3
|
2
|
1
|
| Dependence: Difficulty
quitting and avoiding relapse: perceived need
to use |
4
|
3
|
1
|
2
|
| Intoxication: Impairment
of motor abilities, distortion of thinking
and mood |
3
|
1
|
4
|
2
|
In the table
above cannabis is rated as having the lowest
addictive potential on four of the five
criteria identified, with heroin most strongly linked
to reinforcement and tolerance, tobacco to dependence
and alcohol to intoxication and withdrawal severity.
Data on
drug-related deaths
Drug related
mortality measures one of the more extreme
consequences of drug use, but one that seems
relatively free from measurement problems. There are
however, two problems in considering death data
one that relates to cause and one that relates
to attribution. The causal question results from the
distance of time between cause and the effect
if an individuals heart is weakened by chronic
heavy drinking and they die from a heart attack, it
is not obvious whether or not this is a
alcohol-related death. This has been the
subject of much politicised debate around smoking
mortality. A second, related issue, concerns the
proximal attribution of the death thus, in the
case of overdose, the death may be recorded as a
heroin death in spite of the presence of excessive
quantities of alcohol or benzodiazepines. Thus, even
death data must be considered in terms of the
recording practices employed.
Box 3: Problems
interpreting drug related mortality data.
the
deceased may be long term addict or occasional
recreational user
death may
be accident, suicide or possibly homicide
death may
be due to direct, indirect or long term effects of
drug use
dependent
drug use is not always recorded as cause of death in
situations such as where drug addict dies in fire,
road traffic accident, of viral infection (HIV,
hepatitis)
drugs
involved may be controlled drugs, prescribed
substances or a mixture
the drug
may not be detected at post mortem or recorded on
death certificate
whether a
drug is detected may depend on which part of body
sample is taken from
whether a
drug is detected may depend on how soon after death
post mortem is carried out
there is
much variation between coroners in facilities,
resources and workloads
what is
recorded as verdict/cause of death is at the
discretion of coroner (drug use may be omitted for
relatives stigma).
Table 18: Number
of deaths where target substance mentioned on death
certificate. Source: Office for National Statistics
database on drug related deaths.
| SUBSTANCE |
ANNUAL NUMBER DEATHS 1997 |
| ALCOHOL |
28,000 (over 3000 cases
alcohol specified on death certificate) |
| AMPHETAMINES |
40 |
| BENZODIAZEPINES |
temazepam 104; diazepam
122; nitrazepam 14 |
| CANNABIS |
13 |
| COCAINE HYDROCHLORIDE |
38 |
| FREE BASE COCAINE |
- |
| AMPHETAMINE TYPE (ecstasy)
|
11 |
| HALLUCINOGENS |
1 |
| VOLATILE SUBSTANCES |
78 |
| TOBACCO |
120,000 |
| HEROIN |
255 |
| METHADONE |
421 |
An alternative
approach to risk: capture rates
The issue of the
relative impact of prevalence of use on danger is the
basis for the capture rate approach. Although it is
important to know prevalence, it is just as important
to be able to work out how many of those who try a
drug will go on to use it regularly or to become
dependent on it the capture rate
for a drug.
Much of this
information comes from the American National
Comorbidity Survey (Anthony, Warner and Kessler,
1994). In a national household survey, they asked
about lifetime use and lifetime dependence for a
range of psychoactive substances. An estimated 24% of
the total sample had developed tobacco dependence at
some point in their lives, 14% alcohol dependence and
7% dependence on an illicit drug.
However,
significantly more people had used alcohol or tobacco
than had ever used illicit drugs. Therefore, the
authors also calculated the proportion of those who
had ever used a drug who had gone on to develop
dependence (see table 19 below):
Table 19:
Prevalence, dependence & capture
rates by target substance.
Drug
|
Proportion who have used %
|
Proportion who have
developed dependence %
|
Proportion of dependence
among users %
|
Tobacco
|
75.6
|
24.1
|
31.9
|
Heroin
|
1.5
|
0.4
|
23.1
|
Cocaine
|
16.2
|
2.7
|
16.7
|
Alcohol
|
91.5
|
14.1
|
15.4
|
Cannabis
|
46.3
|
4.2
|
9.1
|
What this would
suggest is that tobacco has the greatest potential
for dependence followed by heroin, then cocaine and
alcohol. Cannabis has the lowest
addictability of all the drugs listed
above.
[method
problems]
However, the
capture rate approach may be slightly misleading in
that it assumes that the people who have ever tried
heroin are the same as the people who have ever tried
alcohol so that the capture score is a property of
the drug and not of the user. Yet we know that being
offered drugs in adolescence has been associated with
poor neighbourhoods (Crum et al, 1996), with divorced
parents (Grady et al, 1986) and with prior use of
alcohol or tobacco (Stenbacka et al, 1993). For this
reason, the frequency of the shift from
experimentation to dependence reflects not only the
addictiveness of the drug but the characteristics of
those who are willing to experiment with it.
[method
advantages]
Yet the capture
rate approach is a particularly promising method for
those who wish to study the longitudinal dangers
associated with a range of substances. Thus, there is
no reason why this approach should be restricted to
the relationship between experimenters and dependent
users. An entire capture risk chain could be, in
principle, calculated in which the start point is the
first time the drug is offered to an individual,
followed by first use, then regular use, then
dependent use, and so on. Similarly, a capture
equation could be made for first use to particular
forms of morbidity and mortality. This method would
permit an actuarial approach in which hit
rates could be calculated for substance effects
according to the requirements of the policy makers.
General
developmental issues & danger
[Variables,
adolescence & independence-assertion]
The
developmental approach assumes that, across
populations, there are predictable patterns of
deviant careers in which most people will flirt with
delinquent behaviours (such as drug use) during
adolescence, but will grow out of these
in early adulthood. This will be true for all but
around 5% of young delinquents, who will develop
long-term and serious problems associated with their
adolescent delinquency. In contrast, most adolescents
will go through a brief spell of
independence-assertion, called
adolescent-limited delinquency, during
which they will reject the value system of their
parents. This will lead to a period in which deviance
is valued, petty crime committed, where excessive
drinking is commonplace and where recreational drug
use occurs. In general, early adulthood signals the
end of this period, with employment and marriage the
most frequent catalysts.
[Variables,
expectations]
Thus, there is a
danger period for two aspects of substance use
initiation and escalation that are not independent of
each other. The developmental approach has generally
involved a consideration of risk factors
as the key determinants of harm or danger. These
include background characteristics such as parental
drug use and family income, anti-social personality,
low intelligence and other factors that may increase
the risk of all kinds of lifetime problems. On the
other hand, there are also contemporary-contextual
factors that influence the decisions made here and
now about whether to use a drug. These may include
availability, opportunity, peer influence and
expectancies about what the drug will do. This
distinction allows us to incorporate both general
factors that will shape risk-taking behaviour across
the life course with factors that will determine the
outcome of a particular risk situation.
General
discussion
[context, social
expectations]
The first point
to make here is that the dangerousness of an
individual substance is difficult to abstract from
the context of its use a context that is
likely to include the individual taking the drug,
their expectations and beliefs about the drug, the
society that defines these beliefs and the likelihood
of sanctions and the state of the individual at the
time of consuming the drug. This state will reflect
not only predisposition (biological and
psychological) but other forms of substance use that
have been engaged in before or at the same time as
the target drug.
The
dangerousness of a drug cannot be generalised across
all situations the criterion specified and the
method of calculating both the likelihood of and the
extent of the negative outcome [must be?] clarified
so that it is consistent with the objectives of the
policymaker initiating the assessment of danger.
This is why the
capture rate approach offers such a potentially
useful method of calculation. As it requires the
clear specification of the outcome (e.g. mortality
rate) and the delineation of the calculation criteria
(e.g. as a proportion of all problem users or
lifetime users), the comparability between
populations and between substances is less evidently
skewed.
Similarly, for
the policy-maker attempting to assess the adequacy of
the statistical information available, it permits a
clear delineation of the gaps in the data necessary
to make this form of calculation.
A further point
this raises is about the temporal aspect of
measurement. If it is accepted that the dangerousness
of a drug is not exclusively a function of the
pharmacological properties of the substance, then
there are likely to be ephemeral factors (such as
availability and purity) that will influence the
likelihood of particular negative outcomes. The
ability to measure shifts in these danger outcomes is
also crucial to understanding shifting risk patterns,
the efficacy of public health interventions and
changing patterns of drug use. To this end it is
critical not only that measures of dangerousness are
maximised, it is also crucial that they are obtained
consistently across time.
Implications
[Variables]
there are some
intrinsic logical issues that prevent clear
delineation of risks by substance use:
a. factors
related to the substance in particular, the
quantity and purity of the drug consumed.
b. how this
relates to factors in the consumer their
physiological frame and state, their history of
consumption and consequences for tolerance, and
psychological factors including expectations and
psycho-adaptation to the drug. Individual factors
will also be mediated by career variables
including age and developmental state as well as
other use forms.
c. combination
use the concurrent or consecutive use of
several drugs both within and across drug classes
provides an enormous confounding effect on the
prediction of effects.
d. route of
administration while it is generally
acknowledged that use by injection carries the most
immediate risk it should not be assumed that other
routes smoking and swallowing in particular
are without hazards.
[social context,
beliefs, law]
What this
implies is that the actuarial calculation of risk
associated with any given substance is a
multi-faceted assessment embedded within the typical
use patterns and circumstances commonly undertaken in
particular societies.
This is partly a
reflection on both societal and sub-cultural beliefs
and preferences, but will also be impacted upon by
the legal framework within which use occurs. Thus,
there is a fundamental dysjunction between the risks
associated with readily available legal drugs such as
tobacco and alcohol, and the illicit drugs, for which
a criminal justice component is inherent in the
profiling of dangers. Thus, while swallowing cocaine
may be generally less harmful than its injection,
this is not the case for the cocaine dealer who
swallows a package to avoid criminal detection.
[perceived
benefits of drug use]
the current
project does not attempt to enumerate the positive
effects that may be associated with substance use,
although it readily acknowledges that part of the
risk relates to this reinforcing quality and the
functionality of much substance use.