Brain: Searching for Roots of Fear

You are taking a hike up a —pleasant and calming—with the sun shining dully through the brown tinted leaves. Suddenly, a rattlesnake appears at your feet.

At that very moment you experience something. You freeze, your heart starts to pound faster and faster, then you begin to sweat frantically—a quick, automatic sequence of physical reactions. That reaction is fear.

A couple of months later your friend wants to go hike the same mountain. You are taking the same walk again but this time it is different. The sunshine and pleasure are still there, but no rattlesnake. Still, you are worried that you will encounter one. The experience of walking through the woods is fraught with worry. You are anxious.

This simple distinction between anxiety and fear is an important one in the task of defining and treating anxiety disorders, which affect many millions of people, accounting for more visits to mental health professional each year than any of the other categories of psychiatric disorders.

Scientists merely define fear as a negative emotional state triggered by the presence of a stimulus, such as the snake, that has the potential to cause harm. Whereas, anxiety is defined as a negative emotional state in which the threat is not present but anticipated.

Society often confuse the two. For example, a student "afraid" he will fail the brutal final exam that he did not study for, should by the definition stated above, use "anxious" instead.

However the truth is, the line between fear and anxiety can get cloudy and fuzzy. If you saw the rattlesnake at a particular rock on the hike, and are now at that spot, the rock may stand in for the snake and elicit fear, even though the snake itself is nowhere to be found.

In the modern world, many fear states are like this—they are brought on by things, signposts or signals that stand for harm rather than things that are truly harmful. For example, after the Sept. 11, 2001, terrorist attacks, many Americans feel uneasy at the sound of low-flying airplanes.

How do things come to symbolize threats? Take students at , for example. When the bells rings for lunch, all the kids automatically rise from their seats to rush to the lunchroom with hungry, craving stomachs. This happens because the bell previously has run and the students stomachs have fluctuated with joy. The students' brain has formed an association between the sound and the food.

As the above examples, Sept. 11, 2001, and the rattlesnake, illustrate, the same thing happens in dangerous situations.

Pathological fear and anxiety are due to alterations of the brain system that normally control fear and anxiety. A tremendous amount has been learned about the normal system from studies of animals, whch gives us a good shot at understanding the pathological forms and developing ways to treat and maybe even prevent them.

Indeed, extensive research in animal models are giving scientists new clues about how to treat problems of fear and anxiety in humans, but is it actually possible to pull people back once they've crossed that blurry line?