Scientists at the Feinberg School of Medicine at Northwestern University have recently developed a blood test to diagnose depression in adults, making this approach the first scientifically objective diagnosis for the illness. According to Dr. Eva Redei, co-lead author of the study, “This test brings mental health diagnosis into the 21st century and offers the first personalized medicine approach to people suffering from depression.”
Depression is commonly diagnosed through a clinical interview, where a mental health professional evaluates the patient by discussing various factors including symptoms and family history of mental illness. Dr. Redei believes that this blood test has the potential to erase the stigma often associated with a diagnosis of depression because it allows the illness to be tested like any other physical illness.
How the Study Worked
Dr. Redei and a team of researchers compared the blood samples of 32 patients who had been diagnosed with depression in a clinical interview and compared their samples with 32 people without depression. They found nine RNA blood markers that differed significantly between the two groups. RNA molecules carry out the instructions of the DNA genetic code and are considered the “messengers” of genes. This discovery led the researchers to form a basis for a diagnosis of depression.
The patients who had been diagnosed with depression then underwent 18 weeks of cognitive behavioral therapy, which is an evidence-based treatment for depression that focuses on proactive ways in which patients can interpret and cope with their environment. Upon re-testing their blood, Dr. Redei discovered the patients who had benefited the most from therapy had changes in their RNA markers, further showing a biological and objective way to determine if treatment was working.
Perhaps most interestingly, Dr. Redei discovered that three RNA markers did not change in depressed patients, regardless of whether their blood work showed that they had benefited from therapy. She suspects that these markers may show a predisposition to depression, a groundbreaking discovery that could possibly pinpoint individuals who are vulnerable to the illness even if they have never experienced symptoms of depression.
Because this research is still in an early stage, there are several factors that should be further investigated before the FDA will approve the blood test for every screening of depression. Regardless, researchers believe they are coming closer and closer to the point where there will not be a question as to whether mental illness is a matter of will.