The Netherlands ranks in the European top three when it comes to ketamine use, along with Belgium and Germany, according to a sewage water analysis by the European drug agency EUDA. Ketamine remnants in Dutch sewage increased by over 40 percent compared to 2024, AD reported.

More ketamine was found in Amsterdam, Eindhoven, and Utrecht than in 2024. In Eindhoven, the amount of ketamine increased by over a third. Rotterdam saw a decrease, but the city still ranks in the European top 20.

Amsterdam also topped the European ketamine list last year. Thomas ter Laak, who provided the Dutch data on behalf of the water research institute KWR, points out that a Belgian study three years ago observed an increase in ketamine in sewage water between 2012 and 2023. So he thinks the increase could be structural.

The Netherlands remains Europe’s top MDMA user, with Amsterdam topping the list by a considerable distance. However, the researchers did note a decrease in MDMA residues in Amsterdam for the first time since the pandemic.

Cocaine is most popular in the Netherlands and Belgium. In absolute terms, cannabis remains the most widely used substance, especially in the Netherlands and Germany, though Slovenia is catching up.

The researchers also looked at amphetamine (speed) and methamphetamine (crystal meth). Historically, these drugs are much more popular in Eastern Europe and are rarely seen in the Netherlands. Relative to 1,000 inhabitants, Eindhoven, Utrecht, and Rotterdam are the main amphetamine users in the Netherlands.

The researchers tested samples of sewage water daily for a week in 115 cities in 25 countries, focusing on “typical” weeks with no holidays or festivals in the area. For drugs like cocaine and MDMA, the researchers noted an increase between Friday and Monday, with traces of both drugs peaking on Sundays. According to the EUDA, this indicates primarily recreational use on weekends.