The report, produced by the UN Office on Drugs and Crime (UNODC), also indicates that drug use has stabilised in the developed world but is growing in the developing countries.
Globally, the number of people using amphetamine-type stimulants -- estimated at around 30-40 million -- is soon likely to exceed the combined number of opiate and cocaine users, it said.
There is also evidence of increasing abuse of prescription drugs."We will not solve the world drugs problem if we simply push addiction from cocaine and heroin to other addictive substances - and there are unlimited amounts of them, produced in mafia labs at trivial costs," Antonio Maria Costa, chief of UNODC, said.
The market for amphetamine-type stimulants is harder to track because of short-trafficking routes as manufacturing usually takes place close to the main consumer markets and the raw materials are both legal and readily available.
"These new drugs cause a double problem," Costa said.
"First, they are being developed at a much faster rate than regulatory norms and law enforcement can keep up. Second, their marketing is cunningly clever, as they are custom- manufactured so as to meet the specific preference in each situation," he added.
On the other hand, the report shows that the world's supply of the two main problem drugs – opiates and cocaine – is declining.
Coca cultivation, down by 28 per cent in the past decade, has declined in 2009.
World cocaine production has declined by 12-18 per cent over the period of 2007-2009.
Global potential heroin production fell by 13 per cent to 657 tons in 2009, reflecting lower opium production in both Afghanistan and Myanmar.
The actual amount of heroin reaching the market is much lower (around 430 tons) since significant amounts of opium are being stockpiled, according to the UN.
The World Drug Report 2010 shows that in the past few years cocaine consumption has fallen significantly in the US and shifted across the Atlantic to Europe where the number of cocaine users in Europe has doubled, from 2 million in 1998 to 4.1 million in 2008.