Conclusions About Cannabis Use and Harms

1. In the last half century recreational use of cannabis has become widely established among teenagers and young adults in a broad range of developed countries and in some developing countries. In developed countries with the longest history of use, a substantial minority of users continue their use into middle age and beyond.
2. There are a number of health harms from smoking cannabis. Cannabis use impairs functioning in exacting tasks, and use before driving probably increases the risk of a traffic crash.  About 10 percent of those who try cannabis develop dependence on the drug, and they have a higher risk of respiratory disorders, of impaired cognitive functioning (at least in the short term), and of developing psychotic symptoms or a psychotic disorder. Early and heavy use by adolescents may increase the risks of poor educational and other psychosocial outcomes in young adulthood.
3. The probability and scale of harm among heavy cannabis users is modest compared with that caused by many other psychoactive substances, both legal and illegal, in common use, namely, alcohol, tobacco, amphetamines, cocaine and heroin.
4. Recently, concerns have been expressed about increased potency of cannabis products. Average THC content in many countries probably has increased, at least in part because of the illegality of cannabis production. The health consequences of any such increases will depend on the extent to which users can titrate the dose of THC.
5. There are variations over time in rates of cannabis use within and between countries, but these variations do not seem to be affected much by the probability of arrest or penalties for use or sale, however draconian.  The widespread pattern of cannabis use indicates that many people gain pleasure and therapeutic or other benefits from use.
6. It is probable that cannabis users who drive while intoxicated can harm others.  Measuring tools are now available to establish whether a driver is under the influence of cannabis and regulations and enforcement to deter this behaviour should be broadly implemented.  Other harms to others from cannabis use are less well established.  Role-failures from cannabis dependence (in work and family life) are probably the most important.

 

Conclusions About the Effects of Current Policies

1. There have been long standing efforts to deter cannabis use by prohibition and policing.  Enforcement efforts in most countries have focused on the arrest  of users.  In developed countries with large cannabis-using populations, the criminal penalties actually imposed for possession and use are usually modest by comparison with those possible by law. Moreover the probability of being arrested for any one incident of cannabis use is in the order of less than one in one thousand. The enforcement effort has not had much success in deterring use.
2. The rationale for severe penalties for possession offenses is weak on both normative and practical grounds. In many developed countries a majority of adults born in the past half-century have used cannabis.  Control regimes that criminalize users are intrusive on privacy, socially divisive and expensive.  Thus it is worth considering alternatives.
3. In addition to the substantial government resources expended in enforcing a prohibition regime, such a regime imposes very large secondary costs and suffering at the personal level.  For example, a criminal conviction for cannabis possession can exclude an individual from certain jobs and activities, and arrest can impose personal and family humiliation.  In countries where data are available, arrest rates are sharply higher for many minority and socially disadvantaged groups.
4. Measures to reduce penalties or to decriminalize possession and use have been adopted in numerous jurisdictions without an upsurge in use.  Moreover these reform measures have had some success in ameliorating the adverse consequences of prohibition.  However, the benefits of decriminalization can be undercut by police practices which may increase the number of users penalized, or by discriminatory enforcement of the law.

 

Beyond the International Treaties

1. The present international treaties have inhibited depenalization and prevented more thoroughgoing reforms of national cannabis regimes.  Regimes which do go beyond depenalization or decriminalization have been characterized by inconsistencies and paradoxes.  For example, the Dutch coffee shops may sell cannabis products through the front door, but are not supposed to buy their supplies at the back door.
2. That which is prohibited cannot easily be regulated’. There are thus advantages for governments in moving toward a regime of regulated legal availability under strict controls, using the variety of mechanisms available to regulate a legal market, such as taxation, availability controls, minimum legal age for use and purchase,  labeling and potency limits. Another alternative, which minimizes the risk of promoting cannabis use, is to allow only small scale cannabis production for one’s own use or gifts to others
3. There are four main choices for a government seeking to make cannabis available in a regulated market in the context of the international conventions: (1) In some countries (those that follow the expediency principle), it is possible to meet the letter of the international conventions while allowing de factolegal access.  The Dutch model is an example.
4. If a nation is unwilling to do this, there are three routes which are the most feasible:
   • Opting for a regulated availability regime which frankly ignores the conventions.  A government that follows this route must be prepared to withstand   substantial international pressure.
   • Denouncing the 1961 and 1988 conventions, and re-acceding with reservations with respect to cannabis.
   • Along with other willing countries, negotiating a new cannabis convention on a supra-national basis.

5. The record is mixed concerning whether making cannabis use and sale legal in a highly regulated market would lead to increased harm from cannabis use in the long run. Experience with control regimes for other psychoactive substances teaches that lax regimes and allowing extensive commercial promotion can result in high levels of use and of harm, while stringent control regimes can hold down levels of use and of harm.
6. A nation wishing to make cannabis use and sale legal in a regulated market should draw on the substantial experience with other relevant control regimes for psychoactive substances.  These include pharmacy and prescription regimes, alcohol sales monopolies, labelling and licensing, availability and taxation controls.  Special attention should be paid to limiting the influence and promotion of use by commercial interests. Attention should also be paid to the negative lessons from the minimal market controls which have often applied for tobacco and alcohol, as well as to the positive examples.

 

Principles for Policy Analysis

1. Our policy recommendations below are guided by general ethical principles of public health action: measures to reduce harm should be proportional to the harm they aim to prevent, they should as far as possible have positive consequences and avoid negative ones, they should minimize effects on individual autonomy and they should be fairly enforced, particularly with regard to the less powerful or more marginalized groups.
2. Current cannabis policies may do some good, but there is a dearth of evidence in support of that claim. They clearly do harm to the many individuals who are arrested, they abridge individual autonomy and they are often applied unjustly. The enforcement of cannabis prohibition is also costly.  The task is to devise policies that do better, taking all these aspects into account.  We recognize the importance of the constraints imposed on policy by popular opinion which usually supports a retention of prohibition.
3. The principal aim of a cannabis control system should be to minimize any harms from cannabis use.  In our view this means grudgingly allowing use and attempting to channel such use into less harmful patterns (e.g. by delaying onset of use until early adulthood and encouraging all users to avoid daily use or driving a car after using).

 

Policy Recommendations

1. Making policy recommendations involves value judgements and assessments of uncertainties.  We offer our own recommendations for what constitutes good policy toward cannabis, recognizing that reasonable people can differ on the relevant values and in their assessments of contingencies.

 

Actions inside the box of the current international control regime:

Under the current international control regime, the cannabis policy options available to governments are arguably limited to varying the severity of penalties for use. Given that more than minimal enforcement of prohibitions seems to do little to reduce use, the principal policy concern should be to minimize the adverse consequences of prohibition.

1. If a nation chooses to use the criminal law for controlling cannabis use, there is no justification for incarcerating an individual for a cannabis possession or use offence, nor for creating a criminal conviction. Retaining a criminal law on possession on the books as a handy tool for discretionary police use tends to result in discriminatory application of the law against the disadvantaged. Police should give very low priority to enforcing laws against cannabis use or possession.
2. A better option, the acceptability of which is more questionable under the international conventions, is to process violations administratively outside the criminal justice system.  Fines should be low, and alternative sanctions such as referral to education or counseling should not be onerous, reflecting the proportionality principle.

 

Setting the international conventions aside:

1. The international drug control regime should be changed to allow a state to adopt, implement and evaluate its own cannabis regime within its borders.  This would require changes in the existing conventions, or the adoption of a new pre-emptive convention.
2. In the absence of such changes, a state can act on its own by denouncing the conventions and re-acceding with reservations, or by simply ignoring at least some provisions of the conventions.
3. Any regime which makes cannabis legally available should involve state licensing or state operation of entities producing, wholesaling and retailing the drug (as is true in many jurisdictions for alcoholic beverages).  The state should, either directly or through regulation, control potency and quality, assure reasonably high prices and control access and availability in general and particularly to youth.
4. The state should ensure that appropriate information is available and actively conveyed to users about the harms of cannabis use.  Advertising and promotion should be banned or stringently limited to the extent possible.
5. The impacts of any changes, including any unintended adverse effects, should be closely monitored, and there should be the possibility for prompt and considered revision if the policy increased harm.