Could a blood test be used to diagnose, monitor clinical depression?

Statistics show that clinical depression is a reality for more than 18 million people here in the U.S. What's perhaps even more staggering is that many medical experts have indicated that the methods for diagnosing clinical depression -- subjective observations of moods and behaviors coupled with firsthand patient information -- are not always effective.

Interestingly, this may all soon change for the better thanks to the efforts of researchers at Northwestern University who may have found a much easier way to not only diagnose clinical depression, but also determine whether cognitive behavioral therapy is working.

According to the researchers, who published their findings in the latest edition of the medical journal Translational Psychiatry, a simple blood test -- akin to that used for checking a patient's cholesterol levels -- could perhaps be used to diagnose clinical depression.

The blood test developed by the researchers examines levels of nine distinct RNA blood markers, which they determined appear in differing levels among those suffering from depression and those who are not. In general, RNA is a cellular component responsible for a variety of functions, including processing and executing the instructions found in DNA genetic code.  

As part of their study, the researchers also tested the blood of 32 clinically depressed study participants ranging in age from 21 to 79, finding that the levels of the nine RNA blood markers changed significantly among those who reported feeling better after receiving 18 weeks of cognitive behavioral therapy.

This study, while preliminary, is certainly encouraging in that it could not only provide physicians with a better diagnostic tool, but also help them determine whether a patient is showing improvement thanks to therapy. This last point is particularly important as not all patients respond to antidepressant medications.

It's important to remember that if you have been diagnosed with clinical depression or another type of debilitating mental illness that prevents you from working that you may be eligible for Social Security disability benefits to help make ends meet.

Source: CBS News, "New blood test could be first to detect clinical depression," Jessica Firger, Sept. 16, 2014