Bristol: A loss of taste may be a sign of depression, according to scientists at the UK’s Bristol University.

When levels of our good mood chemicals fall in the brain our taste is desensitised. On the other hand when levels of mood enhancing chemicals such as serotonin and noradrenaline increase, sense of taste improves.

The team from Bristol University say their findings, which examined the links between brain mood chemicals and taste, could explain why loss of appetite often goes hand-in-hand with depression.

Their discovery could lead to the development of a taste test allowing doctors to quickly and accurately choose the right drug to treat a patient’s depression. But this will not be available for several years.

In the study volunteers were asked to taste a range of foods and their ability to pick up different tastes was rated.

They were then given antidepressants which raise the levels of serotonin or noradrenaline.

The results showed that raising serotonin levels enhanced their ability to recognise bitter and sweet tastes.

Raising noradrenaline levels made them more sensitive to bitter and sour tastes.

Some anti-depressants such as Prozac raise serotonin levels. Edronax increases the amount of noradrenaline. Other drugs can improve levels of both chemicals.

Doctors currently have no way of knowing which medicine will work for which patient and often initially prescribe the wrong drug.

Being able to pinpoint the right drug early on would enhance recovery from the condition that affects one in five Britons at some point in their lifetime.