In 2001, nearly two decades into Pereira’s accidental specialisation in addiction, Portugal became the first country to decriminalise the possession and consumption of all illicit substances. Rather than being arrested, those caught with a personal supply might be given a warning, a small fine, or told to appear before a local commission – a doctor, a lawyer and a social worker – about treatment, harm reduction, and the support services that were available to them.

The opioid crisis soon stabilised, and the ensuing years saw dramatic drops in problematic drug use, HIV and hepatitis infection rates, overdose deaths, drug-related crime and incarceration rates. HIV infection plummeted from an all-time high in 2000 of 104.2 new cases per million to 4.2 cases per million in 2015. The data behind these changes has been studied and cited as evidence by harm-reduction movements around the globe. It’s misleading, however, to credit these positive results entirely to a change in law.

Portugal’s remarkable recovery, and the fact that it has held steady through several changes in government – including conservative leaders who would have preferred to return to the US-style war on drugs – could not have happened without an enormous cultural shift, and a change in how the country viewed drugs, addiction – and itself. In many ways, the law was merely a reflection of transformations that were already happening in clinics, in pharmacies and around kitchen tables across the country. The official policy of decriminalisation made it far easier for a broad range of services (health, psychiatry, employment, housing etc) that had been struggling to pool their resources and expertise, to work together more effectively to serve their communities.

Portugal’s radical drugs policy is working. Why hasn’the world copied it?