The European Union is being inundated with ultra-potent cannabis, significantly increasing the risk of psychosis and other mental health disorders, according to a warning from the EU’s drugs monitoring agency.
Alexis Goosdeel, director of the EU Drugs Agency (EUDA), told the Financial Times that some of the cannabis now circulating in Europe is up to five times stronger than what was smoked at the iconic 1969 Woodstock festival. “It’s a concern because with such a high potency, the probability of it being the cause of a psychotic episode or other mental health issues is much higher,” Goosdeel said.
The warning comes as several EU member states — including Germany, the Netherlands, Luxembourg, Malta, and the Czech Republic — have either decriminalised cannabis, launched legalisation plans, or expanded regulated access. Germany decriminalised possession of small amounts and permitted home cultivation last year, while the Netherlands is piloting a legal supply chain to stock its renowned cannabis “coffee shops.”
Goosdeel acknowledged that rising THC potency — the psychoactive component responsible for the drug’s “high” — is a worrying trend, but he argued it is not necessarily a reason to reverse legalisation. Instead, he said, regulation could offer governments the ability to set potency limits, making consumption safer.
According to the EUDA’s annual report released Thursday, cannabis remains the most widely used illicit drug in Europe, with an estimated 24 million adults (8.4% of the population) using it in the past year. Wastewater analyses show Amsterdam, Groningen, Barcelona, Tarragona, Oslo, and Lisbon as some of Europe’s heaviest cannabis-consuming cities.
The report also reveals that the average THC content in cannabis resin — often used in edibles or mixed with tobacco — has soared to 23%, up from 13% in 2013. By contrast, traditional herbal cannabis now averages about 11% THC, while cannabis smoked during the Woodstock era contained only around 4%.
Medical research has long linked high-THC cannabis to increased risks of hallucinations, paranoia, and long-term psychotic disorders, especially among young people and those predisposed to mental illness. “There is strong evidence that the impact in terms of psychotic episodes seems to be associated with the fact that some people have a vulnerability. But there is no way to detect the vulnerability,” Goosdeel said.
He also pointed to Uruguay’s experience after becoming the first country to legalise cannabis in 2013. Legal sales there initially lagged behind expectations because the product was significantly weaker than what was available on the black market. Authorities later increased the potency of legal cannabis — within what they considered safe levels — to better compete.
Goosdeel, who will step down later this year after leading the Lisbon-based agency for a decade, leaves amid growing debate over how Europe should balance public health risks with the push for cannabis regulation and market control.
