Blood test can diagnose depression in adults

CHICAGO – A group of Northwestern University professors and researchers has developed a blood test to diagnose depression in adults.

But the discovery does not mean the test can be offered to the public just yet, officials said.

Depression is one of the most difficult mental health disorders to diagnose because patients frequently underreport or inadequately describe their symptoms.

It is also one of the toughest mental illnesses to treat.

The new study found that adults with depression have biological markers of the illness, said Eva Redei, a professor of psychiatry and behavioral sciences at Northwestern’s Feinberg School of Medicine who helped develop the test.

Blood work can indicate if treatment is working.

“If we had an objective, laboratory-based blood test just like a cholesterol test or glucose test, we could reduce the stigma of depression,” said Redei.

For 16 years, Redei has been working to develop a scientific way of diagnosing depression, she said last week. She started her work in laboratory animals and eventually was able to study humans.

She already has developed a blood test that diagnoses depression in adolescents, she said. But her new study shows that the markers in the bloodstream that identify depression in youths are different from the markers in adults.

The results of Redei’s most recent study will be published in the journal Translational Psychiatry. She is co-lead author of the study, along with six other scientists.

To develop their test, Redei and the other scientists examined 32 patients ages 21 to 79 who had been independently diagnosed as depressed. They also tested the blood of 32 adults who weren’t depressed. After studying all the patients’ blood work, the researchers found common markers in the patients who were depressed and those who were not.

The researchers also tested the patients after they underwent 18 weeks of therapy. The tests were able to determine which patients had benefited from the treatment and which ones remained depressed.

“I would really like to see if the test can predict which antidepressant would be beneficial for which patient,” she said.

Now that the results of this study are complete, Redei said she is seeking funding to repeat the experiment in more adults. She also wants to determine whether a blood test can differentiate between major depression and bipolar depression