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Shannon Shelton Miller

Shannon Shelton Miller is an award-winning writer and journalist who specializes in education, parenting, culture and diversity, sports, and health and beauty articles. She has been published in the New York Times, the Washington Post,, Slate, InStyle and the Huffington Post.

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Can a Blood Test Diagnose Depression?

An Indiana University researcher has identified biomarkers that provide clues about a patient's mental health. It could lead to a breakthrough in diagnosis and treatment.

Self-Care & Mental Health

More than 264 million people suffer from depression globally, and many never receive treatment. For those who have access to mental health care, treating depression and mood disorders can often feel like a guessing game with doctors and patients cycling through different medications in hopes of finding what works.

"Mental health is not like other areas where you go to your primary care doctor for lab work and based on that, they adjust your diabetes or thyroid medication," said Dr. Alexander B. Niculescu, a professor of psychiatry at the Indiana University School of Medicine. "We need to have the same standard in mental health care, which unfortunately has been stuck in the 19th century. We want to bring it into the 21st century and make people's lives better by providing cutting-edge, precise mental health treatment as opposed to trial and error."

Niculescu leads an ongoing study examining biological causes for depression and mood disorders, which prompted the development of a blood test that helps diagnose the severity of a patient's mental health condition and matches them to the best medication option. We recently spoke with him about this mental health breakthrough.

This interview has been lightly edited for clarity and length.

Alexander B. Niculescu

HealthyWomen: How could your research change the current state of mental health care?

Alexander B. Niculescu: I'm a practicing psychiatrist and I've been seeing patients with complicated cases for more than 20 years. When somebody shows up with depression, the doctor doesn't know if it's only depression or if the person is also suffering from bipolar disorder. That's a key concern because an antidepressant will make a person with bipolar disorder feel worse over time, and they will experience manic episodes. This also explains why many patients still aren't doing well after they've tried three, four or five different antidepressants because bipolar disorder requires different treatments like mood stabilizers. It can take five to 10 years for somebody to be properly diagnosed as bipolar when they begin to seek treatment after experiencing depressive episodes. In addition to having a blood test that gives you a readout on how you're doing biologically, these markers can indicate how severe your condition might be and match you to appropriate medication.

HealthyWomen: How was the research conducted?

Alexander B. Niculescu: We've been following a cohort of people for 10 to 15 years and seeing what changes they experience with each visit to our lab. We test them when they're doing well and when they're not doing well, and then compare how they describe their feelings with any changes in certain biomarkers we can examine through a blood test. We've looked at depression and bipolar disorder, and we developed a blood test for pain. We then developed a way to figure out which biomarkers should be prioritized in these tests. We started examining those biomarkers specifically in additional populations of clinically ill patients, and once we confirmed we had a good set of biomarkers, we looked into additional independent cohorts to see if these biomarkers could predict who got sick or who could be hospitalized in the future.

HealthyWomen: How would these tests work in real-world settings?

Alexander B. Niculescu: We hope to improve people's lives from the beginning by providing doctors with additional information about a patient's condition through this blood test. A doctor can look at the test, use their clinical judgment, and prescribe a medication that would best fit. We also hope to help pharmaceutical companies develop new and better compounds to help people because there hasn't been much success in recent years with antidepressants. Many pharmaceutical companies are exiting the area of mental health because there haven't been many new breakthroughs or innovations. We hope this can give people more and better options.

HealthyWomen: How soon can we see this in doctor's offices?

Alexander B. Niculescu: We've set up a startup company that can start offering these tests, and we have a laboratory partner to run the tests for us. It's rolling out this year as an early access program for some hospital systems and doctors, but we hope it will be more widely available next year. These are very expensive tests, so the company is working on getting codes for insurance and Medicare reimbursement so we can roll this out more widely.

HealthyWomen: Were differences noticed between men and women?

Alexander B. Niculescu: We found biomarkers that are better for women and biomarkers that are better for men, so we will have specific panels for men and women. The good news for women is that the biomarkers were more accurate. We think some of it is related to women being more comfortable expressing their feelings, so when they were reporting that they felt depressed, that matched with what we saw on the blood test. The connections were good for men, but not as strong as the connections for women. We also think the brain-immune correlation and inflammatory responses are stronger in women, so biomarkers in the blood that correlate with what's happening in the brain are more strongly expressed in women. We saw similar results by gender with the blood test for pain.

HealthyWomen: What future applications do you see for this technology?

Alexander B. Niculescu: As we grow our database, we hope to develop biomarkers tailored to consider ethnic diversity. We haven't seen differences between different racial and ethnic groups, but we're always looking for markers to better optimize our work and see whether certain treatments are better for different groups. So far, it looks like we're all depressed in very similar ways. I also work with a number of veterans, and they're hoping we can determine whether there are biomarkers for post-traumatic stress disorder (PTSD). They know what they're experiencing, and they've told me that having a blood test would validate that their trauma is not just in their head.

As an M.D., I believe in doing no harm and making sure that you're helping people. We're very passionate about this effort and we take our responsibility to patients very seriously.

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