by Ric Treble and Caroline Copeland
The illicit drug trade is international, and different countries have developed different strategies intended to minimize its negative effects, most commonly through controls on, or prohibition of, specified substances. But which approaches to banning substances are actually most effective in reducing harm?
The advent of NPS, and the range of subsequent legislative controls introduced by different countries, has created a natural experiment. Using data from the UK’s National Programme on Substance Abuse Mortality (NPSUM), our study examines how different national and international control strategies have translated into real-world outcomes within England, Wales, and Northern Ireland by examining NPS deaths.
Internationally, there has been a high degree of consistency in drug control. The United Nations (UN) annually reviews and updates the lists of substances (and precursors) named in its drugs conventions, based on recommendations from the World Health Organization’s expert committee. All signatory nations of the conventions are then required to incorporate these controls into their national laws. However, this process of problem identification, data compilation, formulation of recommendations, and achieving international consensus followed by national legislation, is inevitably slow. In contrast, the appearance and spread of NPS within drug markets can be incredibly rapid, so there can be significant delays between local identification of issues arising from novel substances and the international introduction of new controls.
Beyond international laws
In response, some nations have therefore chosen to act sooner, introducing their own national controls in response to local concerns, in advance of, or in addition to, those required by the UN. This means that there is an international patchwork of legislation regarding emerging drug threats, with different substances being controlled in different countries at different times. Whilst challenging for policymakers, this variation provides a valuable opportunity to assess the impact of the application of different nations’ controls on particular substances.
In the UK, there have been very few examples of the illicit synthesis of NPS and the vast majority of such substances are imported instead, often facilitated by internet trading and ‘fast parcel’ delivery services. To address the rapid appearance of NPS, the UK’s Misuse of Drugs Act (1971) has been supplemented by other measures, such as the introduction of Temporary Class Drugs Orders (2011) and the much broader Psychoactive Substances Act (2016). These measures effectively prevented open sale of NPS via ‘head shops’ and UK-based websites. However, NPS remained accessible to both individuals and distributors via internet trading and traditional drug distribution networks.
The power of foreign legislation
Over the period studied, the major sources of NPS in the UK were chemical supply companies based in China. In response to both local and international concerns, China introduced a series of national controls over and above those required by UN scheduling, initially on specifically named substances and, more recently, on whole families of NPS by means of ‘generic’ controls.
When we compared trends in NPS detections within the NPSUM’s mortality data with the timing of the UN’s international control requirements and the UK’s and China’s national legislations respectively, a clear pattern emerged: controls implemented in the producing countries were associated with larger reductions in NPS detections in deaths than controls introduced solely within the consuming country.
Action at home
National legislation within consumer countries is, of course, still essential. It enables national law-enforcement activity, including restricting the import and trafficking supply chain and the implementation of possession offences. However, national legislation and enforcement alone cannot eliminate drug use or its associated harms. For this reason, they must be complemented by wide-ranging harm-reduction strategies. However, legislative controls can also drive unintended consequences. Targeted bans on specific substances often stimulate the development of novel NPS, including the production of new, as yet uncontrolled, variants of substances controlled by name. This pattern has been particularly evident in the case of synthetic cannabinoids, where successive generations of legislation-avoiding substances have continued to appear, prompting the development of ever broader generic controls.
However, even generic controls have limits. Where entire families of drugs are prohibited, new drug families which produce similar effects may emerge instead. This dynamic is currently being seen in the case of highly potent synthetic opioids, a particularly concerning cause of drug-related deaths. Broad controls on fentanyl and their pre-cursors have been followed by the appearance of nitazenes and, as controls on nitazenes are being introduced, a new group of potent opioids, the orphines, has begun to appear. These cycles of control and innovation are therefore likely to continue.
Early legislative action by consumer countries remains necessary to limit the distribution and harms of newly emerging NPS. The findings of our study also demonstrate the particular effectiveness of prompt action to restrict production within source countries to prevent international distribution. If, as a result of Chinese legislative actions, production of NPS for the illicit drug trade becomes more geographically diverse, action to identify new sources of production and to encourage and support supplier nations to restrict production as soon as practicable will be required. This will present particular challenges if the substances being produced and exported are not perceived to present a threat within the producing country.
However, supply-side interventions alone cannot provide a lasting solution: as long as there is sustained demand for psychoactive substances, there will be strong incentives for suppliers to adapt, innovate, and profit. Reducing drug harms will therefore require not only responsive legislation and international co-operation, but also investment in education, prevention, and treatment to address the drivers of demand.
Journal
Frontiers in Pharmacology
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
Legislating novel psychoactive substances: Lessons from 15 years of UK mortality data (2007-2022)
Article Publication Date
29-Jan-2026
