Depression is a disorder that occurs when the levels of chemicals serotonin and noradrenalin fall down in the brain. The decrease of these levels has also been linked to the loss of sense of taste.

Doctors have a lot of problems with realizing which of the chemicals’ levels had decreased and caused depression and with prescribing an appropriate drug. There are drugs that boost the levels of serotonin and the drugs that boost noradrenalin levels.
When choosing which drug to prescribe to a patient that suffers from depressions, doctors get the right drug 60 to 80 percent of the time. It takes them additional 4 weeks to determine if the drug is working or not and then switch drugs if the initial treatment doesn’t help.

This new finding, the link between loss of sense of taste and decreased chemical levels may help the doctors to pick the right drug.

When doctors used antidepressant drugs in patients who lost the sense of taste, their senses improved. When they administered Prozac, a drug that enhances serotonin levels, the patients recognized bitter and sweet tastes. When the noradrenalin levels were raised by using Edronax, the patients recognized bitter and sour tastes.
By developing a sense taste, the researchers are hoping to be able to identify which of the brain chemicals depressive patients lack and prescribe them with an appropriate drug.

Such test should be available within three to seven years.