March 11, 2008 — Researchers may be a step closer to creating a lab test to detect depression.

“We may be able to tell you if you are depressed and more importantly, whether you are responding to the chosen antidepressant therapy,” says researcher Mark Rasenick in a news release.

Rasenick and his team at the University of Illinois at Chicago College of Medicine compared specimens from 16 brains of depressed people who had committed suicide to 16 who had no history of mental illness.

Most of the brains were obtained from men. The researchers found that all the brains had a protein known as Gs alpha. But in the depressed group, the protein pooled in specific areas of the cell membrane. According to Rasenick, this protein is “responsible for the action of neurotransmitters such as serotonin.”

It is believed that this protein could serve as a depression biomarker, leading researchers to create a simple lab test to determine whether someone is depressed.

Rasenick says once a test is developed, “this test could serve to predict the efficacy of antidepressant therapy quickly, within four or five days, sparing patients the agony of waiting a month or more to find out if they are on the correct therapeutic regimen.”

Rasenick and colleagues are expanding the research to confirm the findings.

The study is published in the March 12 issue of the Journal of Neuroscience.