The challenges in developing a rational cannabis policy
Wayne Hall
a
and Michael Lynskey
b
Introduction
If we define a rational social policy as one that uses the
most efficient means to pursue a society’s goals, then
there can be no uniquely rational cannabis policy unless
there is societal agreement on what the goals of the policy
should be. Such policy goals, however, depend on deeper
beliefs about the priority that should be given to compet-
ing ethical values such as individual freedom and the
protection of human health and well being. These turn on
questions about what role, if any, the state should have in
restricting human behavior that primarily harms the
individual. There are major differences of opinion about
these issues in most liberal democracies.
For Millian libertarians, the only relevant factor in decid-
ing on a policy towards cannabis is that individuals should
have the liberty to pursue their own choices so long as
they do not harm anyone else [1
]. Harms arising from
cannabis use that affect the user are solely the user’s
concern; harms that a user may cause to third parties
(such as car crashes if users drive while intoxicated) are
matters for the criminal law. A rational cannabis policy for
a libertarian would, therefore, be one that allowed any
adult to use the drug if they wished. The only restrictions
on its use would be limiting this to those over the age of
adult autonomy (18 or 21 years) and banning use by adults
in situations that put others at risk, for example, driving a
car while intoxicated [2].
Legal moralists, by contrast, believe that (at least some
types of) drug use is inherently wrong (e.g. because they
are intoxicating or undermine autonomy), and that such
wrongful behavior should be criminalized [3]. For legal
moralists, a rational cannabis policy then would be one
that prohibits its use and imposes criminal sanctions on
those who use it. Any societal costs in enforcing the law
are irrelevant to legal moralists, because they argue that
just as laws against murder and theft are inherently right
(and so not evaluated by the costs incurred in enforcing
them) so laws prohibiting the use of cannabis would also
be right and rational.
Many people reject both the libertarian and legal mor-
alists’ views. They are at least conditionally prepared to
accept that the state may have the right to restrict adult
a
School of Population Health, University of
Queensland, Herston, Queensland, Australia and
b
Department of Psychiatry, Washington University
School of Medicine, St Louis, Missouri, USA
Correspondence to Prof. Wayne Hall, School of
Population Health, University of Queensland, Herston,
QLD 4006, Australia
Tel: +61 7 336 55330; fax: +61 7 336 55442;
e-mail: [email protected]
Current Opinion in Psychiatry 2009, 22:258–262
Purpose of review
A rational cannabis policy would arguably be one that minimized the harms of both
cannabis use and the legal policies adopted to control its use. We, therefore, review
recent epidemiological evidence on the harmful effects of cannabis use and social
research on the costs and benefits of cannabis prohibition.
Recent findings
Epidemiological evidence suggests that cannabis increases the risk of road crash injury
if users drive while intoxicated. When used chronically, cannabis can produce
dependence, respiratory disease and psychotic symptoms, especially in vulnerable
young adults. It probably also increases poor educational outcomes and possibly
increases the use of other illicit drugs, although it is debated whether these relationships
are causal. Proponents of a relaxation of cannabis prohibition argue that prohibition has
failed to deter cannabis use, incurs substantial economic costs, has generated a large
black market, has increased the potency of cannabis and users’ access to other drugs
and involves foregone tax revenue from the legal sale of cannabis.
Summary
Development of a more rational cannabis policy requires better evaluations of both the
health consequences of regular cannabis use and of the costs and benefits of enforcing
the existing prohibition on its use. It also requires the liberalization of the international
control system to allow member states to experiment with different methods of
regulating and controlling cannabis use.
Keywords
autonomy, cannabis, drug control, evidence-based policy, policy research, public policy
Curr Opin Psychiatry 22:258–262
ß 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
0951-7367
0951-7367 ß 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI:10.1097/YCO.0b013e3283298f36
Personal choice and community impacts
Submission 116 - Attachment 11
choices if there is good evidence that these choices cause
harm to individuals and society [4
,5
]. Anyone who takes
this view would want to know whether prohibiting can-
nabis use prevents these harms and if so, whether this
outcome is achieved at an acceptabl e social and economic
cost [2]. This approach to policy formulation requires
some form of social accounting that examines the costs
and benefits of both cannabis use and the enforcement of
the prohibition on such use [6
]. A major problem in
undertaking any such accounting is that advocates of both
liberalization and of a continuation of criminal penalties
for use often have very different views on what these
costs and benefits are. The following account briefly
indicates what these contested views are [2,6
].
The harms of cannabis use
The harms of cannabis use can be beneficially divided
into acute harms that arise from a single or a few occasions
of use and chronic harms that arise from repeated use,
often near daily use, that occurs over months, years and
decades.
The main acute risks for cannabis users include anxiety
and panic, especially in naı
¨
ve users, and an increased risk of
accident if a person drives a motor vehicle while intoxi-
cated with cannabis [7
]. Women who smoke during preg-
nancy are more likely to have a low birth weight baby [2].
The most probable adverse health effects of chroni c
cannabis use are: a cannabis dependence syndrome [8];
chronic bronchitis and impaired respiratory function in
regular smokers; cardiovascular disease in older adults
who continue to smoke into middle age; respiratory
cancers in very long-term daily smokers [2]; and psychotic
symptoms and disorders in heavy users – especially those
with a preexisting history of such symptoms, a family
history of such disorders or who begin use in their early
teens [2,9
]. Among the most probable adverse psycho-
social effects of regular use among adolescents are: an
increased risk of cannabis dependence [10
]; poorer edu-
cational involvement and reduced educat ional attain-
ment [11
]; and a higher risk of using other illicit drugs
[12]. The existence of these rel ationships between ado-
lescent use and psychosocial outcomes remain conten-
tious because of the possibility that the associations are
due to residual confounding rather than cannabis use
[12,13].
Most of the adverse health effects of cannabis use are
more likely to be experienced by regular users of the drug
[2,6
]. The most conspicuous exception is a probable
increased risk of a motor veh icle crash if a cannabis user
drives while intoxicated [14]. The increase in the risk of a
road crash is less than that for alcohol-intoxicated drivers,
but the effect is of policy significance.
The public health impact of contemporary patterns of
cannabis use is modest by comparison with those of other
illicit drugs (such as the opioids) or with tobacco or
alcohol [2,6
]. In the case of illicit drugs, this reflects
the absence of fatal overdose risk from cannabis. In the
case of alcohol, it reflects the much lower risks of death
from cannabis-impaired than alcohol-impaired driving,
fewer adverse effects on health and lower rates of regular
cannabis use to into xication. In the case of tobacco, it
reflects the much lower rate of persistence of cannabis
smoking into older adulthood [2].
The costs and benefits of cannabis prohibition
Opponents of cannabis prohibition make a number of
criticisms of it. First, they argue that prohibition has failed
to deter cannabis use. Globally, cannabis is the most widely
used illicit drug, with an estimated 162 million (4%) of the
world’s adults having used it in 2004, a 10% increase on use
in the mid-1990s. In some countries, substantial pro-
portions of all adults and most young adults have used
cannabis [15,16]. In the United States in 2005, for example,
40% of the adult population reported trying cannabis at
some time in their life, and 13% of adolescents reported
use in the past year [17]. Those who defend prohibition
argue that rates of cannabis use would be much higher and
more persistent if its use was legal [5
].
Second, often the substantial police and judicial
resources that are devoted to enforcing the prohibition
on cannabis use are not available for the enforcement of
other criminal laws [18].
Third, cannabis is a much more expensive commodity
under prohibition than it would be if it was sold in a legal
market at a price that reflected the costs of production
and distribution [2]. Its black market price reflects
economic compensation for the risks of arrest and impri-
sonment [18] and, critics argue, this generates large
profits that can be used to corrupt law enforcement
officials [16]. However, because cannabis is easily grown
indoors, it is very difficult for police to prevent its
cultivation, and so there is less need for cannabis growers
to corrupt law enforcement officials [2].
Fourth, critics also observe that there is no control on the
quality of the cannabis sold in the black market [16]. Its
D-9-tetrahydrocannabinol (THC) content can vary in
unpredictable ways, and minors can purchase it in the
absence of age restrictions. The retail cannabis black
market is also not separated from that for cocaine and
heroin, so cannabis buyers may be offered other illicit
substances [15].
Fifth, the largest monetary cost of cannabis prohibition is
the foregone tax revenue that could be raised if cannabis
Developing a rational cannabis policy Hall and Lynskey 259
Personal choice and community impacts
Submission 116 - Attachment 11
was a legal commodity and taxed similar to alcohol and
tobacco [19
]. We cann ot, howev er, simply assume that
the taxation revenue under a legal market would be the
same as the black market value of cannabis. The price of
cannabis would probably be lower in a legal market in
order to undercut the black market [20]. Consumption
could increase if there was rising demand among indi-
viduals who were previously deterred by prohibition,
and if current users used more o ften and for longer
[20,21]. Without knowing how sensitive cannabis use
would be to a lower p rice, it i s difficult to estimate
whatthetotaltaxrevenuewouldbeinalegal
cannabis market. Revenue could nonetheless be sub-
stantial even if not as large as that generated by the
black market.
Other social costs of cannabis prohibition
The risk of arrest is only 1–3% per annum in Australia,
Canada and the United States [2]. This probably explains
the minimal deterrent effects of prohibition, given the
importance of a high risk of detection to any deterrence
effect [15]. The low rate of detection and prosecution for
cannabis use prompts two further criticisms. First, the
failure to enforce a widely broken criminal law brings the
law into disrepute among the young who break the law
without being prosecuted. There is no research on the
impact of disobedience to cannabis prohibition on public
attitudes towards the rule of law, but this hypothesis
deserves investigation. Second, the prohibition against
cannabis use is often applied in a discriminatory way
against unemployed and socially disadvantaged men in
New Zealand [22] and Hispanic and Black minorities in
the United States [6
].
Critics also argue that criminal penalties fail to deter the
minority of cannabis users who are arrested for using
cannabis [15,22]; it also gives them a criminal record that
adversely affects their lives [15] in ways that are more
serious than any harms caused by their cannabis use
[6
,16].
Some critics argue that under prohibition users are given
misleading information about the health effects of can-
nabis [23]. They argue that exaggerated claims about the
adverse health effects of cannabis make young people
sceptical about any health information. A related concern
is that if we tell young people that the health risks of
cannabis are as bad as those of heroin and cocaine, then
benign experiences with cannabis may encourage young
people to underestimate the adverse health effects of
heroin and cocaine [24].
Cannabis prohibition also prevents some patients with
serious chronic illnesses, such as AIDS and cancer, from
using cannabis for medical purposes [25]. There is some
evidence that THC is a modes tly effective antiemetic in
the treatment of nausea and vomiting caused by cancer
chemotherapy, it stimulates appetite in patients with
AIDS-related wasting and it has analgesic and antispas-
modic effects [26]. The number of persons being denied
these benefits is hard to quantify, but one estimate was
that there were 14 000 potential patients in a popula-
tion of 5 000 000 adults in New South Wales, Australia
[26].
Other putative benefits of cannabis use are much more
conjectural. There is no evidence that recreational can-
nabis use improves mental health, as may be the case
with moderate alcohol use [27,28]. The evidence is at
best mixed on whether increased cannabis use reduces
the use of mor e harmful drugs such as alcohol [2,29].
Choosing between evils
The formulation of a rational cannabis policy requires a
societal process for trading off the costs and benefits of
cannabis use against the costs and benefits of prohibiting
its use [2]. Ideally, in a democratic society, this process is,
and ought to be, a deliberative process in which all the
information and arguments that are relevant to the issue
are fairly considered.
In most morally pluralist ic liberal democracies, the for-
mulation of public policies often falls short of this ideal
[11
]. Cannabis policy, for example, has to compete with a
myriad of other pressing issues (such as terrorism, climate
change, oil prices, unemployment, interest rates and
more) for publi c and political attention. The time given
to cannabis policy is often accordingly brief, and policy
debates often radically simplify the deliberation process,
with evidence of harm caused by cannabis use often
taken as supporting current policy [11
]. International
drug control treaties severely restrict the available policy
options by excluding any form of legal cannabis market
[6
].
Politics being the art of the possible, the usual outcome is
a policy compromise that is the most acceptable to the
most powerful and influential citizens. The policy com-
promise that has emerged over the past 20 years in many
developed countries has been a choice between de-jure
or de-facto depenalization of cannabis use. The former
policy that involves legislating to remove criminal sanc-
tions for cannabis possession (and sometimes cultivation)
for personal use has been adopted in some Australian and
US states and in some European countries [6
]. The
latter policy is the more common one: penal sanctions
remain in the statute but they are not enforced, or more
often enforced selectively, with the courts routinely
fining or diverting the minority of users who are prose-
cuted to education and treatment [2].
260 Addictive disorders
Personal choice and community impacts
Submission 116 - Attachment 11
De-jure depenalization of cannabis use has a number of
advantages. First, it nominally removes criminal penalties
for engaging in self-injurious behavior [1
]. Second, it
brings the statutory law into line with actual practice that
is to not enforce the prohibition on cannabis use or to
impose criminal penalties on the minority of users who
come to police attention.
Depenalization also has a number of majo r weaknesses
[6
]. First, it may in fact lead via ‘net-widening’ to an
increase in the number of cannabis users caught up in the
legal system [6
]. If it is easier for the police to fine
cannabis users than to prosecute them, then, more can-
nabis users may be fined, and those who fail to pay fines
may end up before the courts, as has happened in some
Australian states [6
]. Second, depenalizing cannabis use
does not address the problems of the cannabis black
market [6
]. Indeed, it can reasonably be criticised as
hypocritical to pe rmit people to use cannabis, but not
allow a legal market to supply the drug. Third, the policy
does not provide a stable long-term policy solution.
Political pressure often builds either for further liberal-
ization, or, as has happened more recently in Australia,
the UK and the United States, for a return to criminal
penalties. The third weakness can be reframed as a virtue
[11
] if it allows for a more considered cannabis policy to
evolve over the next several decades (during which
political enthusiasm for free markets may have moder-
ated).
Conclusion
Ideally, a more rational cannabis policy could emerge
that will be based on a more accurate evaluation of the
health and other consequences of regular cannabis use
[30] and a better appreciation of the costs and benefits of
enforcing prohibition.
This will only happen, however, if governments are
prepared to fund the necessary research on both of these
important sets of policy issues [2] and if the internat ional
control system is liberalized to allow member states to
experiment with different methods of regulating and
controlling cannabis use [6
].
References and recommended reading
Papers of particular interest, published within the annual period of review, have
been highlighted as:
of special interest
of outstanding interest
Additional references related to this topic can also be found in the Current
World Literature section in this issue (pp. 331–332).
1
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editor. Pot politics: marijuana and the costs of prohibition. Oxford, UK: Oxford
University Press; 2007. pp. 189–207.
This study provides a clear and succinct statement of the case for cannabis
decriminalization on libertarian grounds.
2 Hall WD, Pacula RL. Cannabis use and dependence: public health and public
policy. Cambridge, UK: Cambridge University Press; 2003.
3 Zimring F, Hawkins G. The search for rational drug control. Cambridge, UK:
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4
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5
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prohibition.
6
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A comprehensive review of all the literature that is relevant to the formulation of
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markets; the adverse health effects of cannabis; the social and economic costs of
cannabis prohibition; and the effectiveness and social impact of various ways of
reforming cannabis prohibition.
7
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9
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A comprehensive systematic review of the research literature on the relationship
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10
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ment. London: Academic Press; 2008. pp. 117–148.
A review of the research literature on the nature, correlates and probable con-
sequences of adolescent cannabis dependence.
11
Hall WD. A cautious case for cannabis depenalization. In: Earleywine M,
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An outline of the costs and benefits of cannabis use and cannabis prohibition that
argues the case for depenalization of cannabis use.
12 Hall WD, Lynskey MT. Is cannabis a gateway drug? Testing hypotheses about
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13 Macleod J, Oakes R, Copello A, et al. Psychological and social sequelae
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19
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22 Fergusson DM, Swain-Campbell NR, Horwood LJ. Arrests and convictions for
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