A recent report from the National Programme on Substance Abuse Deaths [1] presents misleading estimates of the number of UK deaths linked to so-called "legal highs" in 2012, according to a letter to The Lancet from Dr Leslie King and Professor David Nutt, writing on behalf of the Independent Scientific Committee on Drugs.

According to the authors, many of the deaths recorded in the report which were widely attributed in the media to "legal highs" (more precisely known as new psychoactive substances) were, in fact, attributable to substances which are already illegal in the UK, such as p-methoxyamphetamine (PMA), which has been a controlled drug in the UK since 1977. Further examples include deaths attributed to khat or anabolic steroids, which are either not new, or not classed as psychoactive. The misuse of medicinal products such as phenazepam was also misrepresented as deaths from new psychoactive substances.

Similarly misleading definitions of new psychoactive substances were used in the Office for National Statistics' 2012 report on deaths related to drug poisoning in England and Wales [2], say the authors, with misuse of gammahydroxybutrate (GHB) accounting for 13 deaths even though this has been a controlled drug since 2003.

"There is...no simple answer to how many deaths were associated, let alone caused, by new psychoactive substances or even "legal highs" in any given period," write the authors. "If we are to develop a sensible drugs policy, such failings of data collection and presentation need to be rectified immediately."