By Dr. Manoj Sharma-

Dr. Sharma is a Professor and Chair of the Social and Behavioral Health Department and an Adjunct Professor in Internal Medicine at the University of Nevada, Las Vegas (UNLV). He is a global expert in health promotion.
Depression, which is characterized by sustained deep feelings of sadness and melancholy, and bipolar disorder which is marked by mood swings between extreme elation and severe depression are two distinct but serious causes of disability. Both require correct diagnosis and distinct treatments. Bipolar illness usually starts in the early 20s but on average takes 8-10 years, often longer, for a correct diagnosis. Needless to say, this delay prolongs the agony of the patient and increases the negative sequelae for the patient and their families. Depression usually starts in adulthood but can occur at any age.
The diagnosis for both these conditions at this point mainly relies on clinical examination and self-reported questionnaires which lead to inaccuracies. This is a big problem, particularly in differentiating unipolar depression from bipolar depression. Bipolar disorder affects about 1% of people but it is commonly misdiagnosed as major depression to the extent that 40% of patients with this condition initially receive an incorrect diagnosis and thus wrong treatment.
Recent advances in the form of developing blood tests to diagnose these conditions hold promise for clinicians to bring more objectivity to the process and for the patients to be diagnosed early and begin timely treatment. A recent article in JAMA Psychiatry by scientists from the University of Cambridge reported that biomarkers through a blood test combined with patient-reported questionnaires enhanced the accuracy of differential diagnosis. A patent on this test by the University is pending.
Likewise, a company in France has developed an RNA-editing-based biomarker blood test for differentiating bipolar depression from unipolar depression. The results have been published in Translational Psychiatry. The test uses artificial intelligence to identify 8 RNA sequences to differentiate unipolar depression from bipolar depression and claims a sensitivity and specificity of over 80% (two indicators that assess the value of any diagnostic test in detecting false positives and false negatives). This test is available for about 900 Euros but is not reimbursable by any insurance and psychiatrists and psychiatric associations have not yet endorsed it.
So, we see that biomarker-based blood tests using both DNA and RNA technology are being developed all over the world. These reinforce the biological basis of psychiatric conditions and make these just like physical ailments. These advances will help in reducing the stigma and discrimination associated with mental illnesses. Soon patients with these illnesses will be diagnosed accurately and with more objectivity and early treatment can be instituted so that they can resume their lives in the mainstream with fervor.