Globally, over 350 million people suffer from depression, according to the World Health Organization. The WHO quantifies the burden of diseases through a calculation called Disability Adjusted Life Years (DALY), where one DALY can be thought of as one lost year of “healthy life.” By the year 2020, depression is predicted to reach second place in the DALY ranking for all ages around the world.
Diagnosing depression presents an additional challenge. The current methods include a clinician’s ratings of depression symptoms and the patient’s self report, which may underreport or inadequately characterize symptoms.
Researchers at Northwestern may be changing the practice in upcoming years. A study published on September 16 details a blood test for diagnosing depression.
The test uses nine RNA blood markers that were found to be significantly different between patients in the study with depression and those without. RNA carries the information of DNA to express genes in the form of proteins.
The test also showed biological indicators of the effects of therapy. The study participants then participated in 18 weeks of cognitive behavioral therapy, in which the patient and the therapist work together to address the challenges of mental disorders in a goal-directed way. The levels of the nine blood markers changed for those who improved from therapy and those who remained depressed.
The markers may also indicate which patients will benefit from cognitive behavioral therapy. When patients had a certain pattern of the nine marker levels, they were more susceptible to improving with therapy. In the future, this may guide decisions on the best treatment for patients.
With the global challenges presented by depression, this blood test may improve the diagnosing and treatment of the condition. The findings from this study will be tested on larger populations in the near future to evaluate the reliability.