With 209 Million Cannabis Users Worldwide, UN Drug Report Delves Into Legalization Impacts

The World Drug Report also analyzes regional trends in cannabis markets, including supply, use, cultivation, perceptions, COVID tendencies and more.

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As regular cannabis use has increased worldwide, so too has the proportion of people with psychiatric disorders and suicides associated with that regular use, according to the United Nations. The number of hospitalizations is up too.

Those were a couple of notable convictions in the five-booklet 2022 World Drug Report released June 27 by the U.N. Office on Drugs and Crime (UNODC). 

Highlighted in the booklet on cannabis and opioids, cannabis remains the most widely used drug worldwide, with more than 4% of the global population aged 15-64—roughly 209 million people—having used cannabis in 2020, a 23% increase from the 170 million people in 2010. The global population increased roughly 13% during that decade.

Some 40% of countries worldwide—notably in Africa and South and Central America—report cannabis as the substance related to the greatest number of drug-use disorders, according to the report.

As cannabis use and THC potencies have increased, there has been a “notable increase” in related treatment admissions and psychiatric comorbidities, per the report.

“Between 2010 and 2019, in the European Union, the rate of people entering treatment with cannabis as their primary drug increased from 27 to 35 per 100,000 of the adult population,” the report states. “In 2019, around 35 percent of all people who entered specialized drug treatment services in the European Union were for treatment of cannabis use. More than half of first-time clients were using the drug daily.”

Cannabis was also the most common substance of use reported in emergency rooms during that timeframe in the EU, where it was present in 26% of acute drug toxicity cases, usually alongside other substances.

In a case-control study conducted at 11 sites in Brazil, England, France, Italy, the Netherlands and Spain involving patients presenting first episode psychosis, UNODC reported that cannabis use was associated with a three times greater likelihood of psychotic disorder compared with individuals who had never used the drug. Also, daily use of high-potency cannabis (more than 10% THC) increased the risk of psychotic disorder more than fourfold compared with the risk of those who had never used cannabis.

Increased Use

Furthermore, harmful patterns of drug use “likely increased” during the pandemic, and more young people are using drugs compared with previous generations, UNODC Executive Director Ghada Waly wrote in the report.

“Care starts with evidence-based prevention and addressing perceptions and misperceptions of risk, including by taking a hard look at the messages our societies are sending to young people,” she said. “UNODC research has shown that perceptions of cannabis harms have decreased in areas where the drug has been legalized.”

The prevalence of cannabis use is the highest in North America, where adult-use legalization has taken effect in Canada as well as 19 states in the U.S.; as well as Australia and New Zealand; and West Africa, according to the report.

Authors of the report drew some of their conclusions about increased cannabis use during the pandemic from a web-based survey in Europe, which showed that people who regularly used cannabis (defined as weekly use) were twice as likely to report increased frequency of use as those who were occasional users during lockdowns and were three times more likely to report consuming greater quantities.

In Canada, those 24 years and younger were more likely to report an increase in the amount and frequency of cannabis use during lockdown restrictions compared to those 25 years and older who used cannabis.

“Among these older people, 25 percent reported using more cannabis during the COVID-19 pandemic, which compares to 46 percent among those aged 16-19 years and 40 percent among those aged 20 and 24 years,” the report states.

Impacts of Legalization

The report also attempts to assess the impacts of full cannabis legalization in Canada, Uruguay and much of the U.S., but acknowledges that systematic differences within countries and different contexts within jurisdictions do not offer a natural experiment in comparing outcomes across jurisdictions. UNODC authors also recognized that the increase in cannabis use the U.S. and Canada started “long before legalization.”

According to the report, “cannabis use among adolescents in state-level jurisdictions and in countries that have legalized cannabis in general seems to have remained stable following legalization, although it remains much higher in these jurisdictions than in most countries that have not legalized non-medical cannabis.”

To much of the likely dismay of many U.S. politicians who continue to oppose state-level legalization efforts, UNODC officials found that any evidence on the increase in driving under the influence and traffic fatalities attributed to cannabis remains inconclusive.

The number of fatalities in which the driver tested positive for cannabinoids as the only substance present increased in Colorado from 23 fatalities in 2013 to 42 in 2019, according to the report.

“However, while individual states such as Colorado may show an increase in traffic fatalities involving cannabis use, it has been argued that this upward trend would have taken place whether or not non-medical use of cannabis had been legalized,” according to the report.

Criminal Justice

UNODC officials expressed more confidence in the criminal justice aspects of legalization, stating that arrests for possession of cannabis use among adults had declined considerably in both absolute number and rates in states that have implemented adult-use and/or medical reform. In Colorado, for example, overall rates of arrest for possession of cannabis declined by 71% in the seven years following the state’s 2012 adult-use legalization. 

But while arrests for cannabis possession declined significantly for adults, the same could not be said for minors.

“Legalization of cannabis is explicitly for adults, and, in most cases, youth possession remains a criminal offence,” the report states “Thus, it is possible that legalization for adults has led to a focus of police attention on enforcing the law for youth.”

In 2019, juveniles accounted for 48% of all cannabis arrests in Colorado compared to 25% in 2012, according to the report. 

While cannabis possession arrests have declined in states that have legalized, other cannabis-related crimes or offenses have emerged, including cultivation on public land, illegal interstate commerce, the diversion of cannabis products out of state, and clandestine THC extraction, according to the report.

The Illicit Market

While lawmakers who vote in favor of legalization continue to state their intentions of eliminating the illicit market through a taxed and regulated system, that prohibition-era market continues to exist alongside licensed operators.

RELATED: California’s Cannabis Market at a Crossroads

In 2021, nearly half of Canadians obtained their cannabis for non-medical use from an unlicensed or illegal source, and in the fourth quarter, specifically, nearly 40% of household expenditure on cannabis products was from unlicensed sources, according to the report.

In Uruguay, by February 2022, around 69,000 people of the estimated 158,000 past-month users (based on 2018 data), or roughly 44%, were accessing cannabis through the legal market, “Thus, the legal market provided cannabis for less than half of regular cannabis users,” the report states.

In California, the illegal cannabis market accounted for about three-quarters of cannabis sales in 2019. In Washington, Colorado and Oregon, among others, licensed operators also continue to operate alongside the illicit market.

“Illegal or black markets continue to exist owing, among other reasons, to price disparities between legal and illegal sources due to taxation, the fact that some jurisdictions within states opt out of cannabis legalization measures and because of individuals or groups cultivating unlicensed cannabis on public property or organized crime groups trafficking cannabis out of state,” the report states.

Indoor Outpaces Outdoor Cultivation

While sustainable business practices continue be a widely conversed topic in the industry, growth in indoor cannabis cultivations seems to have outpaced growth in outdoor cultivations at the global level in 2019 and 2020, UNODC officials reported.

During those two years, the overall net number of countries reporting increased indoor cultivation was three times the net number of countries reporting decreased outdoor cultivation, according to the report.

“While qualitative reporting has strong limitations, the patterns that emerge from it suggest an upward trend,” the report states. “The number of countries reporting indoor cannabis cultivation rose from 48 in the period 2011–2015 to 66 in the period 2016–2020.”

Another key finding from the report was that the carbon footprint of indoor cannabis is between 16 and 100 times more than outdoor cannabis on average.

While countries in North America and Europe have historically been the most prevalent to report indoor cultivation practices, countries in numerous other regions and subregions have also reported indoor cultivation in recent years.


Cannabis legalization in parts of the world appears to have accelerated daily use and related health impacts, according to the UNODC’s World Drug Report 2022. Specifically in North America, that acceleration includes the use of more potent cannabis products and particularly among young adults.

Associated increases in people with psychiatric disorders, suicides and hospitalizations have also been reported. In many countries in Africa and South and Central America, the largest proportion of people in treatment for drug-use disorders are there primarily for cannabis-use disorders.

UNODC research has shown that perceptions of cannabis harms have decreased in areas where the drug has been legalized.

Legalization has also increased tax revenues and generally reduced arrest rates for cannabis possession. 

Cannabis cultivation has trended upward for a decade and is illicitly produced in every region of the world.

Worldwide cannabis use is the highest it’s ever been with 209 million people between ages 15 and 64 using the substance in 2020.

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