“Cheer up!” If you’re one of the estimated 6.7 percent (14.8 million) of American adults who suffer from major depression, hearing those two words may make you want to respond with two other words, the second of which is “you.” Depression is not sadness, you insist. You can’t just “snap out of it.” But now, you may have something to smile about.
Researchers at Northwestern University’s Feinberg School of Medicine have announced the development of the first blood test to diagnose clinical depression in adults, dispelling the notion that depression is “all in your head.” According to a study published in September in the journal Translational Psychiatry, the test—which is the first scientific, objective, diagnostic tool for depression—identifies the disease by measuring the levels of nine RNA blood markers, or molecular levels, proving that while depression is in the mind—it’s also in the body.
The test, developed by Eva Redei, PhD, a Feinberg School professor of psychiatry and behavioral science, is the result of research conducted by Redei and six other scientists who tested the blood of 32 adults who’d been diagnosed with depression and 32 who had not. They found common markers in all of the depressed patients.
The researchers also tested the blood of depressed patients after 18 weeks of therapy, and the test was able to determine which patients had benefitted from the therapy and which had not. “If a patient is resistant to taking medication, it could be predicted if he or she will respond to psychotherapy,” Reidi says. “In the future, we hope to be able to identify who will respond to what medication.”
Redei, who has been working for 16 years to develop a scientific way to diagnose depression in adults (she’d previously developed a blood test to diagnose adolescent depression, which uses different markers), says that the science behind the test will help destigmatize depression. “Patients who did not go to the doctor because they were worried about the stigma can one day have a blood test and say, ‘See? Even a lab test shows that I am depressed,’” Redei says. Jessica Nowillo, MD, a Mount Kisco-based psychiatrist, believes that a scientific test will help both patients and clinicians in terms of accurate diagnoses. The blood test, she says, “is not to replace the diagnostician, but to confirm or rule out other differential diagnoses.”
But don’t fire your $200-an-hour shrink yet: More funding, research, and testing is needed before the test can receive the required FDA approval to be marketed.
Still, the technology exists. Could a cure be next? Says Reidi: “It would definitely bring us closer to that!”