(March 11) - Does demolishing a salty bag of potato chips seem to put you in a better mood? If so, you're not alone, according to psychologists at the University of Iowa who say salt may be nature's anti-depressant.

Researchers based the conclusion on studies on rats. They found that rats that were deficient in sodium chloride avoided activities they normally enjoyed, like drinking a sugary substance or pressing a bar that stimulates a pleasant sensation in their brains.

"Things that normally would be pleasurable for rats didn't elicit the same degree of relish, which leads us to believe that a salt deficit and the craving associated with it can induce one of the key symptoms associated with depression," said University of Iowa psychologist Kim Johnson.

The study cannot definitively conclude that the salt-deficient rats are suffering from depression, but the lack of interest in normally pleasurable activities is a key sign of the condition.

The notion of salt as a natural mood-elevating substance could help explain why people are so drawn to it, despite its known risks for high blood pressure, heart disease and other health problems, researchers said.

Past research has shown that most people consume way too much salt. The worldwide average for salt intake per individual is about 10 grams per day, which is greater than the U.S. Food and Drug Administration recommended intake by about 4 grams, and may exceed what the body actually needs by more than 8 grams.

Johnson said the human body has "a taste system" designed to detect salt, while the brain remembers the location of salt sources. A pleasure mechanism in the brain is activated when salt is consumed.

"This suggests that salt need and cravings may be linked to the same brain pathways as those related to drug addiction and abuse," Johnson said.

Johnson's findings will be published in the July issue of Physiology & Behavior.