Athletes know all about an amino acid called Creatine.

It's been used for decades to improve performance in competition. Our body makes about half of what we need. The rest comes from eating meat and fish. But this dietary supplement appears to do a lot more than just build muscles.

Researchers at the University of Utah and three South Korean universities have documented what may be the brain protecting properties of this substance.

In a specific study involving women with depression researchers observed dramatic improvements in their brain chemistry after combing only five grams of creatine with their daily doses of antidepressant medications.

"What we found is that if you were taking creatine together with your antidepressant from the start, that you would get better twice and fast and twice and much as women who just got the placebo," said Dr. Perry Renshaw with the University of Utah Brain Institute.

The University now has a grant from the Institutes of Health to expand the study to adolescents who have been taking anti-depressants but haven't really been feeling better. Researchers will also look at doses. Is four grams of creatine enough, or would higher doses bring on even more dramatic results?

Though the collaborative study with South Korea involved only women, creatine has the potential to benefit both women and men. For those who don't respond well to anti- depressants, creatine could become an inexpensive way to improve treatment outcomes.

But depression isn't the only malady creatine seems to treat effectively. It's protective effect on the brain is now being tested in third stage clinical trials on patients with Parkinson's and Huntington's disease.

According to Renshaw: "Creatine is really emerging as a compound which may have benefits for the brain that we really have never considered. There are a number of cell and animal experiments where we have a great deal of experimental control that shows adding creatine to the solution in cells or administering it as a supplement to animals does really protect against a range of different brain insults."

How about drug addiction?

Matt, who prefers to keep his full identity anonymous, remains hopeful creatine might become a part of drug rehabilitation. He was addicted to methamphetamine at age eighteen and is now going through rehab at the Journey Healing Centers at Willow Creek. Matt is doing very well in recovery and is now able to recognize how meth addiction was destroying his life.

"I had lost all emotions," he said. "I had no family left. I had completely destroyed all relationships. You burn all your bridges, leaving nothing behind but sadness."

Since depression is as much a part of drug addiction as the addiction itself, creatine may speed up the therapy process. The supplement appears to improve mood, memory and cognitive function, and may actually protect the brain from methamphetamine damage - especially in young people.

"For now, we are recruiting methamphetamine using women who would like to try creatine," Renshaw said. "Our hypothesis: They'll show improvement in mood and cognitive function which could make it easier to use less amphetamine."

"We know methamphetamine causes damage to the neurons of the brain and we know that when we have damage like that, you have a harder time thinking," said Michael Desjardins, who works with those undergoing rehab at the Journey Centers. "You have a harder time processing. A substance like creatine which is natural is something they could take for a period of time to improve the way they engage in treatment.