Crude animal tests slowing down progress for Mental Health treatments
World Mental Health Day
- The ‘forced swim test’ is often used to study depression in mice or rats. Animals are placed in cylinders of water and timed to see how long it takes for them to ‘give up’ swimming. It is thought that depressed animals will ‘give up’ sooner and those that have been given effective antidepressants will keep trying for longer. A similar test is called the ‘tail suspension test’, where mice are literally suspended by their tails and the time taken for them to give up struggling is measured.
- In patients with schizophrenia, the startle reflex is often exaggerated and they react very strongly to loud noises, even when they know they are coming. In the ‘startle test’, mice and rats, who have artificially been given the disease through genetic modification or brain damage, are trapped in cages and blasted with loud noises up to 120dB (which is equivalent to a sandblaster or thunderclap). They are then injected with drugs to see if the drugs have an effect on their reaction. The animals usually freeze, but may also run, jump, defecate in fear or even convulse in response to the noise.
- In an attempt to mimic human anxiety disorders, marmosets are used in cruel tests that exploit their fear of snakes. In these experiments, the animals are first conditioned to become anxious by being repeatedly forced into boxes and blasted with loud noise over a period of several weeks. Once they have become suitably nervous, plastic cobras are introduced into their cages and their reactions are observed. Anxious marmosets are seen to stay as far away as possible from the snake, freeze in fear or make frightened alarm calls.
- Why is mental illness so hard to treat? (2012). Science, 338 (6103): 32-33. http://www.sciencemag.org/content/338/6103/32.full
- New antidepressant suicide risks from infamous trial. (2015). New Scientist, 3039: https://www.newscientist.com/article/mg22730394-500-new-look-at-antidepressant-suicide-risks-from-infamous-trial/