First Blood Test Developed To Diagnose Depression

Clinical depression, a disease that affects millions, has always been subjectively diagnosed. A new blood test from Northwestern University researchers, however, may provide a way to objectively identify measurable indicators of depression.

Diagnosing depression is a very subjective matter, usually based on non-specific symptoms like poor mood or feelings of fatigue. The shortcomings are well known, and a search for a better way to identify the disease has been ongoing for some time. According to a recent press release, a new lab test may allow physicians to diagnose the disease — and even personalize how they treat each patient — based on its results.

“Mental health has been where medicine was 100 years ago when physicians diagnosed illnesses or disorders based on symptoms,” said co-lead author David Mohr, a professor of preventive medicine and director of the Center for Behavioral Intervention Technologies at Northwestern University Feinberg School of Medicine, in the press release. “This study brings us much closer to having laboratory tests that can be used in diagnosis and treatment selection.” 

The study, published in the journal Translational Psychology, describes the new test, which is based on nine RNA markers. RNA molecules translate DNA information into proteins and cell products, and the nine chosen are related to depressive disorders. In a sample of depressed patients who received 18 weeks of cognitive behavior therapy, there was a measurable decrease in these markers. This decline was correlated with the patient’s remission from depression.

In addition, comparing the depressed group to a non-depressed sample of patients showed that the markers indicated who was susceptible to depression, even if they weren’t currently undergoing a depressive episode, according to the study.

“Being aware of people who are more susceptible to recurring depression allows us to monitor them more closely,” Mohr noted in the press release. “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.” 

By looking at different characteristic patterns of the RNA markers, personalization of treatment may be possible to achieve.

“Currently we know drug therapy is effective but not for everybody and psychotherapy is effective but not for everybody,” Mohr said in the press release. “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.” 

Detection of biomarkers is a fruitful area of research, providing early detection of many diseases. In a recent article published on Med Device Online, an RNA biomarker was identified that may allow early diagnosis of pancreatic cancer.