How do antidepressants work?

Robert Thompson Photo: Martin Vloet

In 2001, Americans spent $12.5 billion on antidepressants to treat the debilitating symptoms of depression. Scientists know that antidepressants work by restoring the normal balance of hormones and neurotransmitters in the brain. But no one knows exactly how they do it. Robert Thompson, Ph.D., an assistant professor of psychiatry in the Medical School, is trying to find out.

By analyzing subtle changes in the brains of laboratory rats receiving one of three common antidepressants, Thompson and U-M colleague Juan F. Lopez, M.D., have found 10 to 20 neural genes whose expression patterns change in response to medication. They use advanced DNA microarray technology to analyze the activity of thousands of genes just to find a few that change in response to more than one type of antidepressant. It is tedious, painstaking — but important — work.

The next step is tracking complex biochemical changes in the brain, which are controlled by changes in gene expression. “Understanding how antidepressants work at a genetic and molecular level could help us address their limitations, like delayed responses and side effects,” Thompson says. “It also could lead to new medications to help people who
don’t respond at all to the antidepressants we have today.”

Also:

Conquering Depression

What’s the best way to help depressed teens?

What does stress do to your brain?

Can primary care docs treat depression?

What happens to when Mom is depressed?