Illicit drug usage is practiced by approximately 200 million people globally, Australian researchers reported in the medical journal The Lancet. High-income nations have the highest rates, and disease burdens related to drugs are comparable to the health toll caused by alcohol consumption.

The authors explained that expert estimates of global illicit drug usage range from 142 to 271 million people – approximately 1 in every 20 people aged from 15 to 64 years.

Authors, Professor Louisa Degenhardt, National Drug and Alcohol Research Centre, University of New South Wales, Sydney, and the Burnet Institute, Melbourne, Australia; and Professor Wayne Hall, University of Queensland Centre for Clinical Research, Brisbane, Australia, wrote that the disease burden caused by illegal drug usage is very high in rich nations, for example, in Australia it is about the same as the burden caused by alcohol consumption, but significantly less than tobacco.

Because of the very nature of illicit drugs – they are illegal – it is difficult to gather accurate and reliable data and statistics. It is a serious challenge for health authorities and services to properly determine how many of their citizens are problem users, dependent, or being harmed by taking cocaine, amphetamines or cannabis. The authors explain that these are some of the unintentional negative consequences of making such drugs illegal.

The limitations in gathering accurate and reliable data on the related harms and health burdens attributable to inhalants, non-medical usage of benzodiazepines, or anabolic steroids means that their extents of use have never been properly estimated.

According to data the authors managed to collect, there are globally about:

  • 125-203 million cannabis users
  • 14-56 amphetamine users
  • 14-21 cocaine users
  • 12-21 opioid users
  • Between 15 and 39 million problematic users of cocaine, amphetamines or opioids
  • Between 11 and 21 million individuals inject their illicit drugs

Rates of illicit drug usage vary around the world:

  • Cannabis usage – rates are highest in Australia and New Zealand (Oceania), with a 15% usage rate among 15 to 64 years olds
  • Opioid usage (includes heroin) – rates are highest in the Middle East, with a usage rate that may be up to 1.4%
  • Amphetamine usage – Oceania has the highest rate, about 2.8% of all 15 to 64 year-olds
  • Cocaine – 1.9% of US citizens aged 15 to 64 year olds, the highest rate in the world
  • Speed and crystal meth – Oceania has the highest rate, at about 2.8% of all 15 to 64 year-olds

The researchers emphasized that there is not one standard way of measuring illicit drug usage rates.

There are four main types of adverse health effects caused by using illicit drugs:

  • The acute toxic effects – such as overdosing
  • The acute effects of intoxication – such as violence or accidental injury
  • The development of dependence (addiction)
  • The effects on health on long-term sustained usage (sustained, chronic, regular use), such as physical disease.

Cannabis does not appear to cause overdose, blood-borne virus infections, or a noticeable number of deaths – it can cause some accidental deaths. However, dependency is widespread. The authors believe that cannabis also contributes to some mental disorders.

Opioids cause all four types of adverse health effects, the authors wrote. Approximately 1 in every 4 lifetime users develops dependency. Opioids also cause a considerable number of premature deaths, mainly due to overdosing, as well as accidents, violence, and suicides. A significant proportion of opioid users also take other drugs at the same time. The risk of developing HIV/AIDS and/or hepatitis is also higher among opioid users. An considerable number of regular opioid users become disabled, because of infections, liver disease and dependence.

Below are some more data the authors gathered from WHO (World Health Organization); in 2004, globally there were:

  • 250,000 deaths attributed to illicit drug usage. This is still much lower than alcohol (2.25 million) and tobacco (5.1 million)
  • Years of life lost – Illicit drug use, 2.1 million. Alcohol consumption, 1.5 million. The number is higher for illicit drug use because deaths linked to drug use occur at a much higher rate among young people, compared to death due to alcohol consumption (or even smoking tobacco).
  • Disability Adjusted Life Years (DALYS) – Illicit drug use, 13 million. Alcohol consumption, 69 million. Tobacco, 57 million.

There are other burdens which are important but rarely reported, the authors stressed, such as:

  • Stigma and discrimination
  • The dangers of discarded drug injection equipment
  • Violence between drug dealing gangs
  • Violence and/or robbery/muggings that occur because of illicit drug dependence

Most reporting on the adverse events linked to illicit drug usage focuses mainly on drug dependence, and in particular, those who inject drugs.

The overall burden of illicit drug usage is considerably higher in high income countries than in developing nations

The report added that illegal opioid usage has dropped considerably since the late 1990s.

The authors wrote:

“Intelligent policy responses to drug problems need better data for the prevalence of different types of illicit drug use and the harms that their use causes globally. This need is especially urgent in high-income countries with substantial rates of illicit drug use and in low-income and middle-income countries close to illicit drug production areas.”

Written by Christian Nordqvist