Passed in 2016 in the United Kingdom and due to come into force on 26 May, the Psychoactive Substances Act bans all new psychoactive substances (NPS) except those specifically exempted, such as alcohol and tobacco. The Act has attracted much criticism from scientists and experts. But what better alternative exists? The scientific journal Addiction has today [25 May] published the opening statement in a debate by leading addiction researchers from around the globe.

The opening statement, by Prof Peter Reuter and Bryce Pardo of the School of Public Policy, University of Maryland, outlines three problems with the Psychoactive Substances Act's total ban of NPS:

1. The Act's definition of psychoactivity is too broad: it applies to substances of potential and known minimal to moderate harm.

2. The Act does not provide a way to establish psychoactivity. On this topic, the Advisory Council on the Misuse of Drugs has warned that "There is currently no way to define psychoactivity through a biochemical test, therefore there is no guarantee of proving psychoactivity in a court of law."

3. The Act's penalties for violations of a total ban are not proportional to the harm of the substance involved. Under the Act, judges cannot impose a common sense approach in sentencing since they will have little if any evidence on the harms of the specific drug involved in the case.

On the other hand, Reuter and Pardo point out that total prohibition of NPS has two major potential advantages:

1. The Act will likely reduce the number of different NPS introduced in a given period.

2. The Act should reduce the cost of managing the NPS problem by eliminating the need to study and classify each newly emerging NPS.

Professor Reuter says: "Given the prominence of the United Kingdom in drug policy affairs internationally, the choice made by the UK is likely to reverberate throughout the world. The Expert Panel that developed the Psychoactive Substances Bill identified several alternative approaches but did not have sufficient time to study them fully. So little is known about the subsequent Act's feasibility and consequences that it would have been better to delay until more effort was made to assess all the alternatives."