Long-time depression researcher Eva Redei recently reported some of her latest findings. She has spent decades breeding rats who are severely depressed (mating depressed rats with depressed rats so you get ‘who are believed to be the most depressed rats in the world’ (!!)). This meant she could identify genes linked to depression. Next she exposed a different group of rats to stressful situations for two weeks which enabled her to identify the genes that consistently were associated with a poor response to stress.

The big news is that there was no overlap between the depression genes and the stress genes. This suggests that the idea that stress causes depression may be wrong. And, furthermore, she claims the reason antidepressants are often ineffective is because they treat stress and not depression and she has now shown that the two are not linked, though they may co-occur. So that’s one reason why antidepressants only work for some people (those suffering from stress and depression). Before you say ‘ah well, this is just an effect in rats’, Redei claims that rat brains are very similar to human brains, so it is reasonably to draw analogies. It also may explain why we like cheese. (No, that last bit was a joke).