Scientists develop blood test for depression, bipolar disorder

A group of researchers at the Indiana University of School of Medicine in the United States have developed a blood test that they say could identify mood disorders like depression and bipolar.

The study, which was published in the journal Molecular Psychiatry, also builds on previous research into the blood biomarkers that track suicidality as well as pain, post-traumatic stress disorder, and Alzheimer’s disease.

Biomarkers are indicators of a biological condition often measured using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.

The study described the creation of a test composed of RNA (ribonucleic acid) biomarkers that can distinguish how severe depression is, the risk of developing severe depression in the future, and the risk of future bipolar disorder.

The research took place over four years with about 300 participants primarily from a patient population at the Richard L. Roudebush VA Medical Center using a four-step approach of discovery, prioritisation, validation, and testing.

The participants were followed over time with researchers observing them in both high and low mood states. Each time, they recorded what had changed in terms of the biological markers in their blood between the two states.

They used large databases from previous studies in the field to cross-validate their findings. Thus, they validated the top 26 candidate biomarkers in independent cohorts of clinically severe people with depression or mania.

The biomarkers were tested in additional independent cohorts to determine how strongly they can predict who is ill or who would become ill. This way, they exhibit how to match patients with medications and potential drugs.

“Through this work, we wanted to develop blood tests for depression and for bipolar disorder, to distinguish between the two, and to match people to the right treatments,” said Alexander Niculescu, an author of the study.

“Blood biomarkers are emerging as important tools in disorders where subjective self-report by an individual, or a clinical impression of a health care professional, are not always reliable.

“These blood tests can open the door to precise, personalized matching with medications, and objective monitoring of response to treatment.”

Apart from the diagnosis and therapy discoveries in their study, Niculescu’s team also found that mood disorders are underlined by circadian clock genes, the genes that regulate seasonal, day-night, and sleep-wake cycles.

According to the researchers, the study has opened the door for their findings to be translated into clinical practice.