Image by Paweł Czerwiński via Unsplash / Futurism

In recent years, it's become increasingly clear that clinical depression can leave biological traces throughout the body — and now experts want to take advantage of that to improve the way it's treated.

Scientists say they can now determine the severity of a patient's depression through biomarkers in a straightforward blood test, according to research published in the journal Molecular Psychiatry on Thursday. The Indiana University School of Medicine researchers behind the project say that they developed the test to make the diagnoses and treatment of mood disorders not only more precise and objective, but also to help doctors offer better and more personalized care ­— eliminating the subjectivity and trial and error that happens in depression treatment today.

"This is part of our effort to bring psychiatry from the 19th century into the 21st century," lead study author and IU psychiatrist Alexander Niculescu said in a press release. "To help it become like other contemporary fields such as oncology. Ultimately, the mission is to save and improve lives."

The work provides a far more precise look into how depression changes over time, even at the scale of an individual's circadian rhythm. With all of that information in hand, the researchers say they can also develop and deliver far more precise treatments tailored to a patient's specific, individual case.

"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," Niculescu said in the release. "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," he added.