A new study has found that simply measuring a depressed person's brain activity using an electroencephalogram (EEG) can effectively indicate whether or not an SSRI (selective serotonin reuptake inhibitor) antidepressant would be an effective treatment for their condition.

The study tracked nearly 300 patients diagnosed with chronic major depressive disorder. The participants were randomly administered an 8-week course of sertraline hydrochloride, which is an SSRI class antidepressant, or a placebo. EEG recordings were taken before the trial and one week after commencing treatment.

The main focus of the study was to measure activity in the rostral anterior cingulate cortex (rACC), an area of the brain that previous research has indicated is a good target for predicting a positive response to certain depression treatments. Higher rACC theta activity before treatment was found to clearly correspond with greater treatment response to the antidepressant.

"We showed that the rostral ACC marker predicted clinical response eight weeks later, even when statistically controlling for demographics and clinical variables previously linked to treatment response," says Diego Pizzagalli, joint first author on the new study.

This study is the first to be published as part of a larger multi-center project called EMBARC (Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care). The project involves researchers from several major universities examining a variety of methods to accurately, and objectively, measure biomarkers that can evaluate patients with depression. Other soon to be published studies are set to examine both DNA and blood biomarkers.

The overall goal of the EMBARC project is to incorporate these new diagnostic methods into mental health fields and fundamentally improve the way mood and anxiety disorders are treated. Madhukar Trivedi, from UT Southwestern, is one of the founding organizers of EMBARC, and his research has focused on tracking blood biomarkers that can indicate the best drug-related depression treatments for certain individuals.

"When the results from these tests are combined, we hope to have up to 80 percent accuracy in predicting whether common antidepressants will work for a patient," says Trivedi. "This research is very likely to alter the mindset of how depression should be diagnosed and treated."

While no one individual test will prove completely definitive, the plan is to combine a variety of blood and brain imaging diagnostics to assist doctors in determining the most successful course of treatment for any one individual. This is hoped to remove the frustrating element of trial-and-error doctors currently face when prescribing patients different antidepressants.

Take a closer look at the new EEG research in the video below.

The research was published in the journal JAMA Psychiatry.

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