Currently the standard protocol for diagnosing depression involves asking a patient a series of questions or administering a self-report questionnaire about a patient’s mood, energy level, interest and engagement in activities, appetite, sleep, and so on. A patient’s responses as well as observations of mood and behavior would then be used as an indicator for depression. Depression is often difficult to diagnose because diagnosis is dependent on patients being truthful in reporting symptoms and being clear in their description of symptoms.
Researchers at Northwestern University (Redei et al., 2014) have developed a blood test that examines nine RNA blood biomarkers associated with adult clinical depression. This is the first objective measure of depression that has been developed. The blood test was able to differentiate adults who were clinically depressed from adults who were not depressed in a relatively small sample size of 32 depressed adults and 32 non-depressed controls. The blood test was also able to differentiate which patients benefitted from an 18-week course of Cognitive-Behavioral Therapy (CBT) based on the pattern of the nine biomarkers prior to starting treatment.
The researchers plan to test the results on a much larger sample. They also plan to see if the blood test can differentiate between major depression and bipolar depression. Although this research is preliminary, it is exciting to think that a simple blood test may soon be the standard for diagnosing clinical depression in adults and helping determine which treatment(s) may be most effective.
Source: EE Redei, BM Andrus, MJ Kwasny, J Seok, X Cai, J Ho, DC Mohr. Blood transcriptomic biomarkers in adult primary care patients with major depressive disorder undergoing cognitive behavioral therapy. Translational Psychiatry, 2014; 4(9): e442.