Legalise it? There is no harm-free cannabis policy
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Legalise it? There is no harm-free cannabis policy

THE media often present cannabis policy as a simple choice: either cannabis is harmful to users, especially adolescents, and so should be prohibited; or cannabis is less harmful than alcohol, and so adults should be free to use it in much the same way as alcohol.

While the first view has long dominated debate, the latter is now ascendant – we’ve seen the legalisation of recreational cannabis use in Uruguay in 2013 and eight US states since 2012, not to mention Canada’s plan to legalise recreational use in late 2018.

Advocates of the former view tend to overstate the harms of cannabis and ignore the harms arising from prohibition. Advocates of the latter tend to maximise the gains and minimise the risks of legalisation.

SEE ALSO: Philippines: One day after death penalty vote, House endorses medical marijuana

Daily cannabis use can harm users. This is especially so when use begins in adolescence and continues throughout young adulthood. This pattern of use produces cannabis dependence that is associated with increased risks of psychosis, poor mental health and academic under-achievement. Troubled, socially disadvantaged young people – especially young men – are more likely to engage in this pattern of cannabis use and spend most of their days intoxicated, much like heavy drinkers do.

The health effects of daily cannabis use are probably not as serious as the effects of daily heavy drinking (for instance liver disease and impaired brain function). Nonetheless, spending much of one’s adolescence and young adulthood ‘stoned’ interferes with schooling, working and forming satisfying personal relationships.

Formulating cannabis policy unavoidably involves making trade-offs between the costs and benefits of prohibition and allowing a legal market.

Prohibition has not eliminated cannabis use, but it has reduced regular use. The number of Australians who use cannabis in their lifetime (35 percent), is less than half that of alcohol. The number who have used cannabis within the past year (10.4 percent) is also a fraction of figures for alcohol use. Daily cannabis use (probably less than 2 percent of adults) is a small fraction of the adult daily smoking rate (16 percent).


View of an illegal marijuana crop in the mountains of Cauca, Colombia March 15, 2018. Picture taken March 15, 2018. Source: Reuters/Jaime Saldarriaga

However, prohibition also entails costs. The most obvious is the cost of enforcing the criminal laws against cannabis producers, sellers and users. These laws affect socially disadvantaged males, who predominate among regular users.

On the other side of the debate, legalisation also comes with costs. While legalisation eliminates criminal records for adult users, criminal laws must still be enforced – for instance, laws prohibiting under-age sales and black-market cannabis production. Governments also need to regulate the legal industry.

Tax revenue from cannabis sales can fund treatment and prevention, much like gambling taxes do. In the short term, however, taxes have to be set low enough to reduce black market cannabis sales. Taxes can rise later, unless the cannabis industry is able to prevent this happening.

Tax revenue from legal cannabis sales may also become a policy trap for governments. Like tax revenue from gambling, revenue from cannabis will come disproportionately from the heaviest, most socially disadvantaged users. State governments may also become hostage to the cannabis industry just as they have to the “gaming” industry, which has effectively prevented any restrictions on the size of gaming bets or access to cash machines in gambling venues.

SEE ALSO: Big Tobacco is still king in Indonesia

The legalisation of a cannabis market creates an industry with an interest in expanding sales and profits. Cannabis retailers will attempt to promote regular cannabis use because this is where their greatest profits are. It will attempt to increase the number of new users via sales promotions and campaigns to discount the evidence of harm. It will also lobby governments to loosen regulations.

We can already see evidence of these activities in the US. Glossy magazines glamorise cannabis use, celebrities endorse cannabis strains, and producers are promoting cannabis concentrates that contain 70 percent THC – the principle psychoactive ingredient of cannabis. Such concentrates now account for 20 percent of the legal market in some US states.

In addition, the US cannabis business lobby has just recruited the former Republican House Speaker to campaign for a repeal of national prohibition. If there is a national repeal in the USA, then the tobacco and alcohol industries will be able to invest in cannabis and use their expertise to “grow” the market.

For all these reasons, the commercialised model of cannabis legalisation implemented in the US is likely to increase cannabis use. In the medium term, regular use will probably increase first among current users. In the longer term, the number of new users will probably increase, as cannabis prices fall, access increases and the social stigma of cannabis use declines.


Participants attend the Global Marijuana March 2018, in support of the legalisation of marijuana in Berlin, Germany, May 5, 2018. Source: Reuters/Axel Schmidt

This may take time because cannabis use has declined over the past decade among young people in the USA and other high-income countries, including Australia, for reasons that are not well understood. As cannabis use has declined, those who use cannabis are more likely to be daily users.

So how likely is Australia to legalise recreational cannabis use?

There are major obstacles to legalisation in Australia, as the Greens propose. We do not have citizen-initiated referenda and even if we did, only 35 percent of the Australian public would support the legalisation of recreational cannabis production, sale and use.

Legalisation would also put Australia in violation of UN drug control treaties, such as the Single Convention on Narcotic Drugs. Abandoning the UN treaties would attract international criticism; it would also create precedents for Australian and other governments that want to abandon other inconvenient UN treaties, such as those on human rights and refugees.

SEE ALSO: Victoria becomes first Australian state to legalise medical marijuana

Opinion polls indicate that more Australians support the use of non-criminal penalties for cannabis possession and use. Several Australian states and territories have already removed criminal penalties (South Australia, the Australian Capital Territory, and the Northern Territory). Other states could decriminalise personal use and encourage the courts to impose lesser penalties on people who cultivate cannabis solely for personal use.

This policy could reduce some of the harms of cannabis prohibition while we wait to see the outcomes of cannabis policy experiments in the US and Canada. The Canadian experiment will be the most interesting to watch because Canada aims to legalise in ways that minimise the commercialisation and promotion of cannabis use that have so far characterised the US approach to cannabis legalisation.

By Professor Wayne Hall, a scientist internationally recognised for his research on the health effects of cannabis and public policy responses to cannabis and other illicit drugs. This article originally appeared on