The test as the first objective and scientific diagnosis can predict treatment response via cognitive behavioral therapy according to the behavior of some of the markers, according to Press TV.
The research conducted by the scientists at Northwestern Medicine in Chicago found that the levels of nine RNA blood markers in 32 patients, who were aged from 21 to 79 and had been independently diagnosed with depression after clinical interviews,
The study also shows that the recorded measures were significantly different compared to levels in 32 non-depressed controls in the same age range.
The patients’ various therapies including face-to-face and over the phone during 18 weeks reveal different responses among them.
The created changes in the levels of the markers allowed the researchers to differentiate between patients who had responded positively and were no longer depressed and those that remained depressed.
Examining the baseline levels of the nine markers aided the researchers to identify a "fingerprint" from the blood test that would indicate which patients would benefit from cognitive behavioral therapy, while this fingerprint did not appear in depressed patients who did not have the therapy.
"This distinction could be used in the future to predict who would respond to the therapy," said Eva Redei, who developed the test and is a professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.
“This is the first time a biological indicator has been used to indicate the success of cognitive behavioral therapy in adults suffering depression,” researchers say.
"Being aware of people who are more susceptible to recurring depression allows us to monitor them more closely," said the study co-lead author David Mohr.
An earlier study uncovered an association between blood type and risk of cognitive impairment.
The study showed people with rare blood group, in particular with type AB blood, might be more prone to cognitive and memory decline in their later life.