Substance Abuse

Substance Abuse


    Substance abuse refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. One of the key impacts of illicit drug use on society is the negative health consequences experienced by its members. Drug use also puts a heavy financial burden on individuals, families and society.

    The evolution of the complex global illicit drug problem is clearly driven by a range of factors. Sociodemographic trends are influential such as the population’s gender, age and the rate of urbanization.

    Cannabis remains the most widely used illicit substance in the African Region. The highest prevalence and increase in use is being reported in West and Central Africa with rates between 5.2% and 13.5%.

    Amphetamine-type stimulants (ATS) such as "ecstasy" and methamphetamine now rank as Africa’s second most widely abused drug type. Other substances that were used by children and youth surveyed in Sierra Leone, included benzodiazepines such as diazepam, chlorpromazine and different inhalants, while 3.7% were injecting drugs.

    Injecting drugs carries a high risk of infection with bloodborne viruses such as HIV, hepatitis B and hepatitis C, and the sharing of contaminated needles and syringes is an important mode of transmission for those viruses.


    The bare facts

    We know what can and needs to be done to help reduce the burden of psychoactive substance use. Therefore, WHO is committed to assisting countries in the development, organization, monitoring and evaluation of treatment and other services.

    • The harmful use of alcohol results in 3.3 million deaths each year.
    • On average every person in the world aged 15 years or older drinks 6.2 litres of pure alcohol per year.
    • Less than half the population (38.3%) actually drinks alcohol, this means that those who do drink consume on average 17 litres of pure alcohol annually.
    • At least 15.3 million persons have drug use disorders.
    • Injecting drug use reported in 148 countries, of which 120 report HIV infection among this population.

    Alcohol is a psychoactive substance with dependence-producing properties that has been widely used in many cultures for centuries. The harmful use of alcohol causes a large disease, social and economic burden in societies. Environmental factors such as economic development, culture, availability of alcohol and the level and effectiveness of alcohol policies are relevant factors in explaining differences and historical trends in alcohol consumption and related harm.

    Alcohol-related harm is determined by the volume of alcohol consumed, the pattern of drinking, and, on rare occasions, the quality of alcohol consumed. The harmful use of alcohol is a component cause of more than 200 disease and injury conditions in individuals, most notably alcohol dependence, liver cirrhosis, cancers and injuries. The latest causal relationships established are those between alcohol consumption and incidence of infectious diseases such as tuberculosis and HIV/AIDS.

    A wide range of effective global, regional and national policies and interventions are in place to reduce the harmful use of alcohol, with a promising trend over the past few decades.

    1. Alcohol consumption:
      • Worldwide consumption in 2010 was equal to 6.2 litres of pure alcohol consumed per person aged 15 years or older, which translates into 13.5 grams of pure alcohol per day.
      • A quarter of this consumption (24.8%) was unrecorded, i.e., homemade alcohol, illegally produced or sold outside normal government controls. Of total recorded alcohol consumed worldwide, 50.1% was consumed in the form of spirits.
      • Worldwide 61.7% of the population aged 15 years or older (15+) had not drunk alcohol in the past 12 months. In all WHO regions, females are more often lifetime abstainers than males. There is a considerable variation in prevalence of abstention across WHO regions.
      • Worldwide about 16.0% of drinkers aged 15 years or older engage in heavy episodic drinking.
      • In general, the greater the economic wealth of a country, the more alcohol is consumed and the smaller the number of abstainers. High-income countries have the highest alcohol per capita consumption (APC) and the highest prevalence of heavy episodic drinking among drinkers.
    2. Health consequences
      • In 2012, about 3.3 million net deaths, or 5.9% of all global deaths, were attributable to alcohol consumption.
      • There are significant sex differences in the proportion of global deaths attributable to alcohol, for example, in 2012 7.6% of deaths among males and 4% of deaths among females were attributable to alcohol.
      • In 2012 139 million net DALYs (disability-adjusted life years), or 5.1% of the global burden of disease and injury, were attributable to alcohol consumption.
      • There is also wide geographical variation in the proportion of alcohol-attributable deaths and DALYs, with the highest alcohol-attributable fractions reported in the WHO European Region.
    3. Policies and interventions
      • Alcohol policies are developed with the aim of reducing harmful use of alcohol and the alcohol-attributable health and social burden in a population and in society. Such policies can be formulated at the global, regional, multinational, national and subnational level.
      • Delegations from all 193 Member States of WHO reached consensus at the World Health Assembly in 2010 on a WHO Global stratgy to reduce the harmful use of alcohol.
      • Many WHO Member States have demonstrated increased leadership and commitment to reducing harmful use of alcohol over the past years.
      • A significantly higher percentage of the reporting countries indicated having written national alcohol policies and imposing stricter blood alcohol concentration limits in 2012 than in 2008.
    Other psychoactive substances

    Recent estimates are that in 2008, 155 to 250 million people, or 3.5% to 5.7% of the world's population aged 15-64, used other psychoactive substances, such as cannabis, amphetamines, cocaine, opioids, and non-prescribed psychoactive prescription medication. Globally, cannabis is the most commonly used (129-190 million people), followed by amphetamine type stimulants, then cocaine and opioids.

    The use of psychoactive substances causes significant health and social problems for the people who use them, and also for others in their families and communities. WHO estimated that 0.7% of the global burden of disease in 2004 was due to cocaine and opioid use, with the social cost of illicit substance use being in the region of 2% of GDP in those countries which have measured it.

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