Depression is not just a thing of the mind. It's a thing of the blood, too.
A new study, published in Translational Psychiatry, found that it is possible to identify depression with a simple blood test. Researchers developed a blood test which can find molecules in the blood associated with depression.
The study was able to identify nine RNA markers in the blood that differ between people with clinical depression and people who don't suffer from depression. Using a blood test that searched for these markers alone, lead author Eva Redei, Ph.D., was able to correctly identify depression in adults.
Those who think that people with clinical depression can just "snap out of it" should take this study to heart. Depression is a disease, with real physical symptoms, like diabetes or heart disease. People who suffer from depression need help and support to get treatment.
Depression can be hard to diagnose, but this test could be an easier way to find depressed people and help them. Imagine if your doctor could screen for depression as easily as she screens for vitamin deficiencies.
But the new study does one better: the blood test for depression, once fully developed, may also be able to help identify which treatment patients would benefit most from. It may also be able to identify markers of risk for depression even before someone becomes really depressed.
The new study consisted of 64 people, half of whom had depression and half of whom did not. Redei tested the patients' blood at the start of the study, and then had the patients with depression go through 18 weeks of cognitive behavioral therapy. When she tested their blood again at the end of the therapy, she was able to tell which participants benefited the most from therapy. The possibilities for this test are endless - it offers physical proof that depression exists, and that CBT can effectively help some people.
Redei said she hopes this test can make people understand depression more and make it less of a taboo subject. She hopes that once there is an approved blood test for depression, people will feel less bad about being diagnosed.
"I really believe that having an objective diagnosis will decrease stigma," Redei said. "Once you have numbers in your hand, you can identify that [depression] is an illness -- not a matter of will."
According to another study, it can take a long time for depression to be diagnosed. Cases of major depression often take up to 40 months to be diagnosed, a 2010 study found. While there is a stigma associated with visiting a psychiatrist for diagnosis, many people may be too embarrassed to seek the help they need. However, if blood tests for depression became routine, it may help people to get treatment before depression becomes more of an issue. Psychiatrists believe early treatment is key for helping people with depression.