Narrator: This is Science Today. Researchers are trying to track genes that may be able to better predict how depressed patients will respond to certain antidepressants. Dr. Steve Hamilton, a psychiatrist and geneticist at the University of California, San Francisco says previous studies have found that genes thought to be related to the biological processes that antidepressants were linked to, were actually not involved to a great extent.

Hamilton: What this highlights is that we know very little about how antidepressants work - what they do in the brain. We know that they work and we know there's a period of time that's usually required for them to work, but we are only now beginning to get a glimpse of the biological processes that are underlying people getting better on these drugs.

Narrator: Hamilton's work so far suggests that genes they had not previously known about may actually be involved.

Hamilton: If we're able to identify more specific targets for these drugs through genetic analysis that may give us a leg up in coming up with better treatments that make people feel better faster and with much more reliability.

Narrator: For Science Today, I'm Larissa Branin.