The test, created by Northwestern University researchers, promises to change the way mental illnesses are diagnosed

Sep 18, 2014 20:59 GMT  ·  By
Researchers develop blood test that can diagnose depression, predict response to therapy
   Researchers develop blood test that can diagnose depression, predict response to therapy

Presently, specialists looking to figure out whether or not an individual might be suffering from depression have no choice but to talk to that person and try to get an accurate reading of what exactly is going on inside their health.

Poor mood, fatigue and changes in appetite are among the textbook symptoms of depression. The problem is that, because such symptoms can either be ignored by the patient or poorly interpreted by a physician, diagnosing depression is still a tricky business.

Thanks to researchers with US' Northwestern University, identifying the people suffering from this mental condition might soon be a very easy thing to do. Thus, as detailed in a recent paper in the journal Translational Psychiatry, these brainiacs have developed a blood test for depression.

How to use blood to diagnose depression

Study co-lead author Eva Redei explains that, in order to develop this biological test for depression in adults, she and her colleagues started by looking at the makeup of blood samples collected from several dozen volunteers.

All in all, the scientists studied the blood of 32 people already diagnosed with depression and 32 healthy individuals who served as a control group. It was thus discovered that the depressed patients and the volunteers in the control group had distinct levels of nine RNA blood markers.

Following these initial tests, the people that were suffering from depression at the beginning of the study were asked to attend cognitive behavioral therapy sessions for a total of 18 weeks. Once the treatment period was over, the researchers once again tested their blood.

During this second round of laboratory analyses, they found that the makeup of some of the volunteers' blood had changed and had come to resemble that of the healthy individuals. The patients who experienced this change in RNA blood markers were the ones that had responded to therapy.

Hence, it was concluded that a blood tests focusing on pinning down the levels for the RNA blood markers linked to depression would efficiently serve as a tool to diagnose this mental condition in the laboratory and not by sitting down and talking to the patient.

“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,” researcher Eva Redei said in a statement.

“This test brings mental health diagnosis into the 21st century and offers the first personalized medicine approach to people suffering from depression,” the Northwestern University scientist went on to comment on the importance of this research project.

Looking at blood to predict the outcome of depression therapy

What's interesting about this study is that, according to Eva Redei and fellow researchers, blood analysis focusing on the same nine RNA blood markers can also serve to predict how a depressed patient will respond to cognitive behavioral therapy.

Specifically, the scientists claim that, as shown by their experiments, people who recover from depression after undergoing said form of therapy have a specific baseline pattern of marker levels. This pattern was not documented in the case of the volunteers whom cognitive behavioral therapy failed to help.

The importance of this study

The Northwestern University specialists behind this research project expect that their work will help make it easier to diagnose and treat depression. Specifically, they argue that their blood test has high chances to pave the way to more effective, individualized treatment options for depressed patients.

“Mental health has been where medicine was 100 years ago when physicians diagnosed illnesses or disorders based on symptoms. This study brings us much closer to having laboratory tests that can be used in diagnosis and treatment selection,” explained study co-lead author David Mohr.

Furthermore, “Currently we know drug therapy is effective but not for everybody and psychotherapy is effective but not for everybody. We know combined therapies are more effective than either alone but maybe by combining therapies we are using a scatter-shot approach. Having a blood test would allow us to better target treatment to individuals.”