Although the use of drugs such as heroin and cocaine is declining in some parts of the world, there has been a proliferation in the use of prescription drugs and new psychoactive substances.

That information comes from the UN Office on Drugs and Crime (UNODC) which has just released the 2013 World Drug Report.

The agency says while these so-called “designer drugs” are marketed as “legal highs,” their effects are not well known.

Anne Thomas at the UN information office in Vienna asked Thomas Pietschmann, a UNODC Research Officer, about the report’s main trends and findings.

Duration: 2'30"