New blood test suggests depression is an illness, not a state of mind

A new, simple blood test shows promise in diagnosing depression rapidly, indicating whether treatment is successful, and identifying those who may be predisposed to developing the condition.

by John Tyburski

Copyright © Daily Digest News, KPR Media, LLC. All rights reserved.

First published at Daily Digest News on September 17, 2014

Diagnosing depression has remained an inexact science, taking months if not years to come to definitive conclusions. Depression also comes with significant social stigma, and a general notion that depression is a state of mind that its suffers chose to enter persists.

A new report published recently in the journal Translational Psychiatry challenges the dominant depression paradigm by suggesting that diagnosing depression can be as simple as a rapid blood test. By identifying molecular associations with depression, the authors of the report also provide cogent support for the idea that depression is an illness that is outside the will of its sufferers.

Eval Redei and colleagues at the Northwestern University Feinberg School of Medicine found strong correlations between depression diagnosed using gold standard assessments and altered molecular concentrations in the patients’ blood. Using the altered molecular signatures, the new test can be used to not only diagnose depression but also predict which therapies may work best for which patients. One of the more surprising features of the test is that the predictions can be made in patients with no prior history of depressive episode.

Redei said that finding a molecular basis for depression has the potential to take some of the stigma out of the condition. Confirming depression in the same way physicians confirm other ailments means that depression may exhibit many common aspects that come with other diseases, challenging the popular notion that depression can be changed with one’s own will.

“I really believe that having an objective diagnosis will decrease stigma,” Redei said in a statement. “Once you have numbers in your hand, you can identify that [depression] is an illness — not a matter of will.”

The blood test involves a measurement of nine specific RNA molecules which were found to differ significantly in depression patients compared with healthy individuals. The RNA molecules are among many that link the instructions in genetic DNA to proteins, the molecules that carry out the genes’ instructions.