It’s huge progress for both animals and science: Following urging from PETA U.K., the use of the forced swim test (FST) to model human depression is likely to end in the country!
Influential scientists working for the U.K.’s Medicines and Healthcare products Regulatory Agency have concluded in a scientific paper published online that the FST and equivalent tests on animals cannot predict the effectiveness of potential new antidepressant drugs. The authors cite PETA’s work with pharmaceutical companies to end the test, in which small animals are dropped in beakers of water and forced to swim for their lives.
After reviewing the evidence and seeking input from experts, the authors have independently reached the same conclusions as PETA scientists: The FST is not a model of depression and could even rule out effective new drugs for humans. U.K. animal-experiment regulators commissioned the paper, so it’s safe to say that the absurdity of the test has finally been recognized, and scientists must now devise more effective, ethical, human-relevant alternatives.
More Than Half a Century of Terror
Since its inception in the 1950s and its unfortunate rise to popularity in the late 1970s, the FST has been used by experimenters in crude attempts to study human depression and find new antidepressant drugs. In the test, experimenters put mice, rats, guinea pigs, hamsters, or gerbils in inescapable containers filled with water. The panicked animals try to escape by attempting to climb up the sides of the beakers or even diving underwater in search of an exit. They paddle furiously, desperately trying to keep their heads above water. Eventually, they’ll start to float.
According to published reports, the test has been widely used—up to 700 papers describe FST experiments published over the course of a year. In each experiment, tens to hundreds of small animals may be used.
Experimenters have claimed that the FST can be used to measure despair and screen potential antidepressant drugs for humans, but experts disagree.
The test doesn’t accurately predict whether a drug will work as a human antidepressant. It yields positive results for compounds that aren’t prescribed as human antidepressants, such as caffeine, and negative results for some compounds that are. Antidepressant compounds that could work in humans may be mistakenly abandoned based on the test, a point made by the authors of the new paper:
“[I]f excessive reliance is placed on the FST as a gatekeeper for clinical development, then the existence of potentially effective ADs [antidepressants] that are inactive in the test will remain unknown. In the absence of compelling data on the neurobiological basis of the FST and its translatability to [humans], this remains a possibility.”
After hearing from scientists with PETA and our international affiliates, most major drug makers—including Johnson & Johnson, Bayer, GlaxoSmithKline, AbbVie Inc., Roche, AstraZeneca, Novo Nordisk A/S, Boehringer Ingelheim, Pfizer, and Bristol Myers Squibb—have already left the FST in the dust.
PETA U.K. previously wrote to the country’s Animals in Science Regulation Unit, which initiated this review, regarding the validity of the FST and the dubious grounds on which experimenters are authorized to use it.
The test has also been banned by two major research universities in the U.K., including King’s College London, where another author of the paper is employed.
The scientists who wrote the new paper also reiterate the widely accepted fact that the FST “is no longer regarded as an animal model of depression.”
It’s clear that the test will soon be a thing of the past.
Take Action for Animals Today
Despite a vast industry move away from the FST, there are notable holdouts: Eli Lilly and Sanofi are dragging their feet. Urge them to be on the right side of history—a decision that most of their competitors have already made—and ban the cruel test: