I just read this interesting article about overactivity in the amygdala and how a failure to activate the ventral prefrontal cortex can contribute to some people being more subject to anxiety reactions.
I know that with the use of hypnosis and NLP we can retrain the brain.
Quote from this article:
"If we can train those individuals who are not naturally good at this to be able to do this, we may be able to help chronically anxious individuals as well as those who live in situations where they are exposed to dangerous or stressful situations over a long time frame,"
Click here for the article