The UK has one of the highest number of users of “legal highs” in Europe, according to a UN report.
Figures showed that 8.2% of people in Britain surveyed in 2011 had taken psychoactive substances, generally called “legal highs”.
Portugal also ranked in the top tier on the European chart, showing 5.8% of people saying that they had used such substances. The majority of countries on the continent had lower, and often much lower, percentages.
The report from the UN Office on Drugs and Crime said 348 legal highs have been identified in more than 90 countries since 2008. The true number is likely to be much greater as only official sources could be consulted and because new substances are frequently pushed onto the market.
Some 97 new chemical compounds were identified in the last year alone.
Some people buy drugs thinking they are more common substances such as ecstasy without realising they are actually a new designer drug, the UNODC added. If people do not know what they are ingesting, it is far more difficult to get the right emergency treatment.
"Emergency services may therefore find themselves unable to identify life-threatening substances and powerless to administer the proper treatment to users," the 2014 Global Synthetic Drugs Assessment noted.
It warns that designer drugs are a global phenomenon among the young and are no longer restricted to "niche" markets.
"New substances are quickly created and marketed, challenging law enforcement efforts to keep up with the traffickers and curb public health risks."
None of the 348 novel psychoactive substances (NPS), also known as designer drugs, reported at the end of 2013 are currently under international control, the UNODC said.
