This was revealed from the first report in a series of papers published in the journal Lancet. The true number of illegal drug users may be higher than estimated in the report, because the method used to measure the prevalence of drug use, such as household and school surveys, can not be resolved by drug users or people may not admit to drug use.
Researchers using information from the UN Office on Drugs and Crime and other published literature, estimates that there are about 149 million to 271 million people worldwide use illicit drugs.
Most of the cannabis users (125 to 203 million), followed by amphetamine users (14 to 56 million), cocaine users (14 to 21 million) and opioid users (12 to 21 million).
Cannabis users highest in Oceania (Australia and New Zealand), with up to 15 percent of the population aged 15 to 64 years who use drugs. Oceania also has the highest amphetamine, with 2.8 percent of age group who use illegal drugs.
The use of opioids, including heroin use, the highest in the Near and Middle East (up 1.4 per cent of the age group 15 to 64 years), whereas the highest cocaine use in North America (1.9 percent).
There are 4 types of hazards that occur from the use of drugs, namely:
- Toxic effects of drugs, as seen in overdose.
- Intoxication effects, such as injuries due to accidents and violence.
- The development of addiction.
- Adverse health effects of chronic continuous use, such as physical illness, brain damage, HIV /AIDS and hepatitis, as well as contributing to disability.