Supplement Yohimbine May Relieve Anxiety
Preliminary Study Shows Supplement Helps Overcome Fear Faster

By Peggy Peck
WebMD Medical News

April 7, 2004 -- About 19 million Americans suffer from anxiety disorders -- everything from fear of flying to obsessive compulsive disorders -- but now researchers say that a supplement, which causes an adrenaline rush, may turn out to be a new way to treat anxiety.

The drug called yohimbine, which is made from the bark of the yohimbe tree, has a number of uses, but it is probably best known as a treatment for impotence. Mark Barad, MD, PhD, assistant professor in psychiatry and biobehavioral sciences at the University of California, Los Angeles Neuropsychiatric Institute tells WebMD that yohimbine was used before Viagra so it is a drug that people have a lot of experience with.

Barad and his colleagues are interested in yohimbine because it "works on the adrenergic system, which is the system that is associated with adrenaline." He says adrenaline causes rapid heart beat and increased metabolism that are the hallmarks of the so called "fight or flight" response.

The researchers reasoned that if they could manipulate the adrenergic system with medications that turn it on or off, these drugs might also be useful in "training" people to quickly overcome the fear that drives anxiety.

His study is published in the March/April issue of the journal Learning and Memory.

In the study mice were repeatedly exposed to a fearful situation. The mice were then taught how to "unlearn" this fear.

Prior to unlearning this fear, some of the mice were given yohimbine, which triggers a rapid release of adrenaline and symptoms of the "flight or fight reaction."

"Surprisingly, we found that yohimbine, which increases anxiety, actually was useful helping mice overcome fear faster." says Barad.

"We are very optimistic," he says and hopes to get funding for human studies in the future. He says he plans to first test the drug in people with phobias such as fear of heights, but he predicts that yohimbine will be most effective for people with the most severe anxiety disorders, such as obsessive-compulsive disorder.

William Callahan, MD, assistant clinical professor of psychiatry at the University of California, Irvine tells WebMD that "additional drugs with fewer side effects -- drugs that work in a different way from current treatments -- are always welcome and would be a good thing.

He cautions that even the most positive mouse study is, at best, a preliminary finding. "Mice are a lot different than humans," says Callahan, who is a spokesman for the American Psychiatric Association.

Moreover, Callahan, who was not involved in the study, cautions that drug treatment may not be the best approach for people with anxiety disorders. He says even the best drugs may not be useful over the course of a lifetime. Other behavioral therapies may be a better option for many patients, he explains.

Original source: http://www.webmd.com