The first blood test to diagnose major depression in adults has been developed by Northwestern Medicine scientists, a breakthrough approach that provides an objective, scientific diagnosis. The test measures the levels of nine RNA blood markers. RNA molecules are the messengers that interpret the DNA genetic code and carry out its instructions.
The blood test also predicts who will benefit from cognitive behavioral therapy based on the behavior of some of the markers. And the test showed the biological effects of cognitive behavioral therapy’s success. The levels of markers changed in patients who had the therapy for 18 weeks and were no longer depressed.
“This clearly indicates that you can have a blood-based laboratory test for depression, providing a scientific diagnosis in the same way someone is diagnosed with high blood pressure or high cholesterol,” says Dr. Eva Redei, professor of psychiatry and behavioral sciences at the Feinberg School of Medicine, who developed the test. “This test brings mental health diagnosis into the 21st century and offers the first personalized medicine approach to people suffering from depression.”
The current method of diagnosing depression is subjective and based on non-specific symptoms such as poor mood, fatigue and change in appetite, all of which can apply to a large number of mental or physical problems.
Dr. Redei and Dr. David Mohr, a professor of preventive medicine and director of the Center for Behavioral Intervention Technologies at Feinberg, are co-lead authors of the study published in Translational Psychiatry.
Dr. Redei previously developed a blood test that diagnosed depression in adolescents. Most of the markers Dr. Redei identified in the adult depression panel are different from those in adolescents.
The new blood test will also allow physicians to use lab tests to determine what treatments will be most useful for each individual.
“Currently, we know drug therapy is effective but not for everybody and psychotherapy is effective but not for everybody,” Dr. Mohr says. “We know combined therapies are more effective than either alone, but maybe by combining therapies we are using a scattershot approach. Having a blood test would allow us to better target treatment to individuals.”
Another finding ― the blood concentration of three of the nine RNA markers remained different in depressed patients and non-depressed controls, even if the depressed patients achieved remission after the therapy. This appears to indicate a vulnerability to depression.
“These three markers move us toward the ultimate goal of identifying predisposition to depression, even in the absence of a current depressive episode,” says Dr. Redei, the David Lawrence Stein Research Professor of Psychiatric Diseases Affecting Children and Adolescents.
“Being aware of people who are more susceptible to recurring depression allows us to monitor them more closely,” Dr. Mohr notes. “They can consider a maintenance dose of antidepressants or continued psychotherapy to diminish the severity of a future episode or prolong the intervals between episodes.”
The study was supported by grants R21 MH077234 and R01 MH059708 from the National Institute of Mental Health of the National Institutes of Health and by grants from the Davee Foundation.
See journal article: http://www.nature.com/tp/journal/v4/n9/full/tp201466a.html