Researchers take a look at recent data on substance use to find out how it affects health outcomes on a global level.
The review was put together by specialists from prominent institutions worldwide, spanning six countries and three continents: Australia, Europe, and North America.
Its first author is Amy Peacock, who works with the National Drug and Alcohol Research Centre at the University of New South Wales in Sydney, Australia, as well as with the School of Medicine at the University of Tasmania in Hobart, which is also in Australia.
The authors sourced their information mainly through records held by the World Health Organization (WHO), the United Nations Office on Drugs and Crime, and the Institute for Health Metrics and Evaluation at the University of Washington in Seattle.
"Alcohol, tobacco, and illicit drug use are major global risk factors for disability and premature loss of life," the researchers write in the report's introduction.
"Estimating the prevalence of use and associated burden of disease and mortality at the country, regional, and global level is critical in quantifying the extent and severity of the burden arising from substance use."
These are the reasons why the team decided to publicize an up-to-date collection of available statistics — as complete as possible — about the issue of substance use and abuse, and its economic and medical burden around the world.
The report has now been published in the journal Addiction.
Alcohol, tobacco use 'far more prevalent'
Citing the Global Burden of Disease study from 2015, the researchers note that tobacco use has led to 170.9 million disability-adjusted life-years worldwide. Second in line comes alcohol consumption, to which 95 million disability-adjusted life-years are attributed.
No less worryingly, illicit drug consumption has caused individuals around the globe to claim 27.8 million disability-adjusted life-years.
Based on the data available to them, the authors note, "Alcohol use and tobacco smoking are far more prevalent than illicit substance use, globally and in most regions."
About 1 in 5 adults worldwide will have engaged in heavy alcohol consumption on at least one occasion in the past month, which may increase the risk of sustaining injuries.
Also, an estimated 15.2 percent of adults smoke on a daily basis. People who frequently smoke, the researchers warn, are at an increased risk of developing 12 different forms of cancer, respiratory diseases, and cardiovascular diseases, to name but a few related health outcomes.
The data also suggest that the "use of illicit drugs [is] far less common" than the use of alcohol and tobacco worldwide; estimates indicate that "fewer than 1 in 20 people" reported an instance of cannabis use over the past year.
Even fewer people are thought to engage in amphetamine, opioid, or cocaine use. Nevertheless, some regions — including the United States, Canada, and Australasia — have very high rates of illicit drug abuse that warrant concern.
The authors of the report note that Australasia came up as the region with "the highest prevalence of amphetamine dependence," amounting to 491.5 per 100,000 people. Australasian populations also appeared to use other drugs, such as cannabis, opioids, and cocaine, more frequently.
Europeans score high on heavy drinking
The authors also note that, in stark contrast with the populations of other continents, people across Central, Eastern, and Western Europe tend to indulge much more in alcohol consumption.
Per capita, Central Europeans drink 11.61 liters of alcohol per person, Eastern Europeans drink 11.98 liters per person, and Western Europeans consume 11.09 liters.
Europe was also discovered to contain the highest number of people who smoke tobacco, with 24.2 percent of Eastern Europeans, 23.7 percent of Central Europeans, and 20.9 percent of Western Europeans admitting to this habit.
At the opposite end of the spectrum, countries in North Africa and the Middle East reported the lowest rates of alcohol consumption, as well as the lowest percentage of heavy drinking.
However, the authors caution that the findings detailed in their report may not be complete, seeing that many regions — especially Africa, the Caribbean, South America, and Asia — have incomplete or missing data about substance use and its impact on the population's health and well-being.
They therefore advise that in the future, public health organizations should develop and apply more rigorous methods of collecting relevant data and make them available to researchers and public policy-makers.
Still, "Regular compilations of global data on geographic variations in prevalence of substance use and disease burden, such as this, may encourage the improvements in data and methods required to produce better future estimates," they conclude.