What is the Forced Swim Test?
The Forced Swim Test is a cruel and invalid animal test that is used as a misguided attempt to mimic depression or hopelessness in humans. A small animal, usually a mouse or rat, is given an experimental treatment and then placed into a beaker partially filled with water.
Unable to escape, the animal will paddle desperately until they give up and float. Many animals are terrified. The amount of time that the animal spends struggling versus floating is measured. The claim is that when animals spend more time floating, they are deemed to be more “depressed.” See a short video demonstrating this here.
Why is the Forced Swim Test invalid?
The Forced Swim Test is fundamentally flawed and evidence shows that floating is actually a learned and adaptive behaviour, one that saves energy and is beneficial for survival. Individual animals who are quicker to float will save energy and are less likely to sink, meaning that animals who more rapidly pick up on this reality, and spend less time struggling, are simply learning this adaptive behaviour quicker.
The Forced Swim Test doesn’t predict how humans will respond to drugs and has no relevance to human depression. The causes of depression are not properly understood yet - many different factors could contribute to symptoms of depression in humans. Trying to replicate a complex human condition by dropping mice or rats into inescapable beakers of water is questionable, to say the least!
People for the Ethical Treatment of Animals (PETA) scientists have found that in the US, in 30 years from 1989 to 2018, experimenters gave animals 47 different test drug compounds before subjecting them to the FST. 36 of them "showed promise" based on the invalid interpretation of the test. But exactly zero of those are now on the market to treat human depression. Also, an analysis conducted with data from four major pharmaceutical companies found that the Forced Swim Test was less predictive than chance at determining if a compound would have antidepressant efficacy in humans.
Read more about the invalidity of this test here.
Why care about rats and mice?
Rats and mice are social, curious animals who will even take care of a sick member of their community. They can be trained to fetch, roll over and run through obstacle courses, just like a dog! Mice are very chatty and communicate using ultrasonic sound. When tame, mice and rats love being petted and make great companions. These animals deserve to live free from cruelty.
Why do New Zealand universities still use the Forced Swim Test?
In the 1950s, it was thought that the longer an animal in water struggled before ‘giving up’ and floating, the less depressed that animal was. This supposedly showed that the antidepressant had worked and contributed to making the Forced Swim Test become a routine part of testing experimental treatments.
But we’ve learned a lot in the past 60 years – including that the Forced Swim Test is not a valid way to measure if an antidepressant works. In fact, the evidence now shows that the behaviour of the animal in the Forced Swim Test represents a survival strategy rather than a state of ‘depression’.
Find out which NZ universities are using this test here.
Pointless suffering for animals that also harms people
The Forced Swim Test doesn’t predict if new treatments will be effective in humans. This means that antidepressant treatments that might help humans could be abandoned based on the results of this outdated test. More than 95% of drugs that work in animal experiments fail to lead to drugs or therapies for humans and some of the drugs we rely on today would not exist if they’d been first tested on animals.
The Forced Swim Test highlights just how ridiculous the claim is that animal models can predict the human response and go on to save human lives. In the same way mice in cylinders of water with no way of escape, don't accurately model human depression, animals used in cancer, stroke, diabetes research and as a model for any other human illness, is a complete waste of time and resources
What tests should be used instead?
There are already many reliable methods to test human drugs without using animals. These include computer modelling of human systems, and a drug re-purposing programme currently being used in the USA. There is also research into how diseases occur and in what ways drugs can be toxic to humans. More time and resources should be spent on developing additional effective tests for drugs so animal testing becomes a thing of the past. Read more here.
Industry rejects the Forced Swim Test
In Dec 2018 pharmaceutical Giant AbbVie committed to not funding or conducting forced swim tests. Johnson and Johnson (March 2019 ) and DSM Nutritional Products (May 2019) made the same commitment. NutriFusion LLC, Astraea Therapeutics and Roche Pharma (July 2019) have also made a commitment not to use or fund this test in the future. Now, three of the top ten pharmaceutical companies worldwide (in terms of revenue) have committed to no longer use the Forced Swim Test!
This shows that even the pharmaceutical industry is recognising this test as outdated and irrelevant. Now let's make sure NZ keep up with this global shift!
NZAVS and SAFE have joined forces to ask the NZ Government to not only ban the Forced Swim Test in NZ but to also conduct a full review and evaluation on the validity of animal tests used for psychological tests in NZ. Using animals to try and predict human outcomes makes no sense. Read more about the Forced Swim Test and why it needs to be outlawed in NZ here. Find the latest campaign updates here.
To help the many people suffering from addiction and depression, researchers should be looking at human-relevant studies, not torturing and nearly drowning mice and rats. Sign the petition today!
Noteworthy articles recently published:
Depression researchers rethink popular mouse swim tests in Nature (International Journal of Science)
Letter to the editor: Use of the forced swim test to assess “despair” in Brain Stimulation (Basic, Translational, and Clinical Research in Neuromodulation)
Forced-Swim Test Criticized as Uninformative, Cruel in The Scientist (magazine for life science professionals)