Doctors may soon use a blood test to diagnose depression

Researchers at Northwestern University in Chicago have developed a blood test that not only diagnoses clinical depression, but also shows that changing thoughts and beliefs changes brain chemistry. The test provides clear evidence of the mind-body-spirit connection, Karl Benzio, psychiatrist, founder, and director of Lighthouse Network told me.

The study, published last week in the journal Translational Psychiatry compared blood samples from 32 clinically depressed patients with samples from 32 people who were not depressed. The researchers found a significant difference between the two groups in the levels of nine RNA blood markers. RNA is a nucleic acid present in all living cells. The levels of these nine biomarkers identified which patients had depression.

The depressed patients received 18 weeks of cognitive behavioral therapy. CBT, the most widely used psychological talk therapy for depression, is based on the premise that thoughts cause emotions, which motivate behavior. Therapy seeks to change distorted thoughts and beliefs.

A follow-up blood test confirmed patients whose symptoms went into remission following CBT showed changes in the blood levels of the RNA biomarkers. In other words, merely changing thoughts and beliefs resulted in a measurable difference in RNA blood levels and remission of depression.

“The Bible is again validated by science, as the Bible teaches good godly decision-making will renew, or in medical terms, re-wire your mind,” Benzio said, noting most people don’t understand how intricately intertwined spirit, mind, and body are. When doctors discovered medications to treat depression, the treatment focus primarily switched to the biological, ignoring the spiritual.

Although the blood test was not designed to show a genetic component to the disease, much research does indicate a strong hereditary link for mood disorders. The blood test results offer objective, measurable evidence that renewing the mind can even override genetic predispositions, Benzio said.

The blood test is a diagnostic breakthrough for the field of mental health, where early detection and intervention is vital. Fifteen percent of those who are clinically depressed commit suicide. But accurate diagnosis is difficult because it is based on patients’ subjective self-reporting. Those suffering from depression often under-report symptoms, or have difficulty describing what they are experiencing. There is little agreement among various depression scoring systems. And many other disorders mimic depression.

An estimated 12.5 percent of primary care patients have a major depressive disorder in any given year, but only 47 percent of those cases are diagnosed.

It takes between two and 40 months, on average, to diagnose depression. The longer it takes to obtain an accurate diagnosis, the greater the risk of suicide and the more difficult it is to treat the disorder.

The test also will help to remove some of the stigma of depression, Benzio said. So often people think depression is just a sign of weakness or lack of motivation. A lab test could give proof that something is going on biologically.

Three of the biomarkers even distinguished between people whose depression had remitted and those who had never had depression. The test results can identify people who have not yet become depressed but appear vulnerable to the disorder and can tell which patients are likely to benefit from CBT. The blood test may also be useful in monitoring response to other treatments and predicting prognosis. And it may enable doctors to devise individualized treatment plans tailored to the specific needs of each patient.

Before applying for Food and Drug Administration approval, the test will need to be replicated and validated by other independent studies.