Fighting Fear: Researchers Seek Targets for Treatment
"What we are learning is that the amygdala is part of a whole network," Davis says. It is now known that while the amygdala appears to play a subtle yet important role in distinguishing signals of danger, its role appears to be associated with the emotional aspects of danger, rather than the thinking part of the response to fear.
"A face is just a face in the visual cortex, but it becomes an angry or happy face when it reaches the amygdala," explains David Amaral, PhD, a research director at the University of California Medical Center in Davis, who spoke at the conference.
Understanding the different components of fear responses -- both emotional and based on thought -- and how they interact is important for developing treatments, Davis tells WebMD. But in terms of treatment, a major target is getting rid of disruptive memories that can recur and spark fears at any time, he says.
To that end, Davis and his colleagues are now working on the development of compounds to inhibit the reactions triggered by the amygdala. The research is still in its infancy, but someday, they hope these compounds can be used as treatments for a number of fear-related conditions, including posttraumatic stress disorder (PTSD).
PTSD is the severe emotional reaction to a traumatic event, such as a flood, fire, war, assault, domestic abuse, or rape. People with PTSD often re-experience the event in the form of recurring nightmares or flashbacks. These events usually follow the exposure to a symbolic trigger, such as a loud noise or an anniversary of the traumatic event.
At present, PSTD is treated using common behavioral techniques. These techniques are based upon either gradual or frequent exposure of the patient to symbolic triggers of their emotional trauma. The goal of this therapy is to help them gain a sense of mastery over the experience.
Medications also may be used. But for the most part, these medications are used to treat associated symptoms, such as feelings of anxiety.
The goal of the new treatments would be to suppress the fear-related response caused by the amygdala, when it occurs at inopportune moments, Davis says. In essence, he tells WebMD, the goal of the new treatments would be to reinforce the behavioral therapy by helping the amygdala to master the experience as well.
One such compound might be an inhibitor of glutamate, a chemical that transfers messages between nerves and that has been shown to influence various brain functions, Davis says. By inhibiting this chemical in certain parts of the brain, scientists may be able to assist the amygdala to suppress the fear-related response when exposed to symbolic triggers, he says.
According to Davis, there is a desperate need for these types of treatments. Despite the development of newer agents such as Prozac, which has antidepressant and antianxiety properties, the actual treatment of people's fears and phobias has remained largely difficult because these disruptive memories easily can be re-triggered, he says.