03/21/2012 05:35 pm ET Updated May 21, 2012

The Secret Power of Depression

Any student of body language knows that there is one universal truth: Whether we wish to or not, we communicate what we feel. We may keep our mouths shut, but our bodies inevitably find other ways to make our emotions known.

In the language of kinesics, this principle is called "leakage": the involuntary betrayal of emotions through body language and gestures.

We play with a simple version of this principle as children. In the game "Hot or Cold," one player hides an object in a room, and the second player moves around the room, asking whether he is "hot" or "cold." The behavior of the hider, who is sitting on the sidelines, is telling. Some hiders studiously look everywhere but at the hidden object, while others surreptitiously flick their eyes in that direction, as if to reassure themselves that it is still safely tucked away. With still other hiders, it's not so much the eyes as the body -- every movement is telling. If you're watching the hands, the eyes and the feet of the hider, you've got a veritable map. The object can be easy to find, because the person who hid it has been silently shouting its location the entire time.

In trying to understand the evolutionary purpose of depression, scientists like psychiatrist Andy Thomson and evolutionary psychologist Paul Andrews have discovered that depression may function in the same way as leakage. When a person represses their true feelings, depression can serve both to signal the repression and point the way to the hidden object that is causing the pain.

As children, repression is one of the most powerful tools in our emotional repertoire. Traumatic situations frighten and overwhelm us before we have the emotional schema to process and appropriately deal with them. The size of the trauma is irrelevant -- the response it evokes is not. Repression acts as a defense mechanism, but over time it distances people from their true selves.

Numbness, confusion, sadness -- these are signals, the brain's gestures and twitches, designed to reveal that a person has become emotionally out of touch with him or herself. Therefore, scientists theorize that depression lasts longer than mere sadness because it is meant to provoke a ruminative thought process that can naturally lead to deep personal analysis. According to Thomson and Andrews' article in the Scientific American, "Analysis requires a lot of uninterrupted thought, and depression coordinates many changes in the body to help people analyze their problems without getting distracted."

If, as Thomson and Andrews argue, depression serves as "nature's way of telling you that you've got complex social problems that the mind is intent on solving," then therapies that encourage thoughtfulness rather than attempt to stop it can help people truly address their problems.

Even though depression motivates us to address our problems, a person in the throes of depression may not be ready or able to address them alone. With the aid of counseling, our body's clues can be uncovered and used to locate the hidden object -- our true selves.

For more by Evan Bailyn, click here.

For more on mental health, click here.