Taste Test Could Help Depression Sufferers

Ivanhoe Newswire
Friday, December 8, 2006; 12:00 AM

(Ivanhoe Newswire) -- If you're feeling stressed and anxious, potato chips may not give you the salty satisfaction you might sometimes crave. That's because British researchers discovered the more anxious people are, the less sensitive they are to the taste of salt.

The finding is part of new research into the links between taste, brain chemistry, and depression. Now, researchers report a taste test could one day help determine which drug is best to treat depression. Researchers from the University of Bristol in England report levels of certain brain chemicals are not only linked to depressive disorders but also to how well taste buds detect tastes.

Depressed patients have reported a decrease in their sensitivity to all tastes. British investigators wanted to know if there was a neurochemical reason for this effect. They focused on the neurotransmitters serotonin and noradrenaline. Low levels of these brain chemicals are linked to depression. The researchers hypothesized their study subjects would experience fluctuations in their ability to detect certain tastes depending on their brain chemistry.

For the study, three drugs were given to volunteers, including a serotonin specific reuptake inhibitor (SSRI) to raise serotonin levels, a noradrenaline reuptake inhibitor (NARI) to raise noradrenaline levels, and an inactive placebo. Before taking the drugs, investigators tested participants on their ability to recognize certain tastes, like sweet, sour, bitter and salty. Two hours after giving them medications, researchers tested the patients again. The volunteers' anxiety level was also evaluated.

Researchers report taste sensitivities change in response to changes in the two different neurotransmitters. For example, the patients with increased serotonin levels could detect sweet and bitter tastes at much lower concentrations than before taking the SSRI. Patients with increased noradrenaline levels could detect sour and bitter tastes at lower concentrations than before taking the NARI.

The researchers theorize this research could lead to a taste test which would tell doctors which neurotransmitter their depressed patients need more and if the medication is working.

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SOURCE: The Journal of Neuroscience, 2006;26:12664-12671