Blood Test Can Diagnose Major Depression

A first-of-its-kind blood test delivers an objective diagnosis of major depressive disorder, as well as predicts which adult patients will benefit from cognitive behavioral therapy.

Scientists from Northwestern Medicine have developed a blood test that can deliver an objective diagnosis of major depressive disorder, as well as predict which adult patients will benefit from cognitive behavioral therapy (CBT).

According to the developers, the test successfully detects the levels of 9 RNA blood markers tied to major depression. Additionally, it offers measurable, blood-based evidence of the success of CBT in adults with depression, which allows for more effective, individualized treatment.

“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,” said Eva Redei, a professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine who developed the blood test, in a press release. “This test brings mental health diagnosis into the 21st century and offers the first personalized medicine approach to people suffering from depression.”

While major depressive disorder affects approximately 6.7% of the US adult population annually, there is often a 2- to 40-month delay in diagnosis. Consequently, a blood test may provide a timelier and more accurate depression diagnosis, the scientists noted.

“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 Feinberg. “This study brings us much closer to having laboratory tests that can be used in diagnosis and treatment selection.”