Narrator: This is Science Today. Psychiatrists like Owen Wolkowitz of the University of California, San Francisco are excited by a hormone called DHEA. Over the years it's shown an intriguing ability to restore memory. In the 1950s it was given to elderly mice.

Wolkowitz: Their memory performance was restored back to the levels of young mice, even after one dose of DHEA. It was really quite a remarkable finding.

Narrator: In the 1980s, other researchers found that elderly people in nursing homes had lower levels of DHEA and a related hormone than elderly people living independently.

Wolkowitz: And not only that, but within the nursing home groups, those patients that were the most severely impaired had the most lowered levels of the hormones DHEA.

Narrator: Wolkowitz himself gave DHEA to elderly depressed people.

Wolkowitz: We did find that there was significant anti-depressant effects of restoring DHEA levels in these elderly depressed people to levels they saw when they were about 20 years old. We also found that there were specific but significant improvements in memory.

Narrator: The next step: see if DHEA can treat Alzheimer's disease. Wolkowitz is conducting two studies to see if the hormone makes a difference. For Science Today, I'm Steve Tokar.