Amanda Miller developed depression while pregnant with her second child at age 30 in Hershey, Pennsylvania. After giving birth, her depression worsened. In addition, many unexplained health problems arose.
Miller, a neuroscientist, said she has seen several psychiatrists and been prescribed one drug after another. Over the course of two years, she tried four antidepressants and two antipsychotics. None of that helped until her doctor noticed high levels of autoimmune markers in her blood.
Experts then ran “every test in the book,” Miller said. Eventually, she was diagnosed with the autoimmune disease lupus and prescribed steroids to reduce inflammation. Some of her symptoms subsided within hours. Her depression quickly subsided.
“I was convinced it was a placebo effect,” Miller said. “But the effects continued after that.”
Was inflammation contributing to her mental health issues all along? Miller thinks so, but she doesn’t know for sure. Her psychiatrist never raised that possibility, she said.
In most practices, your doctor can confirm whether you should receive some kind of treatment through tests such as blood tests, imaging tests, or biopsies. However, mental illnesses have historically been diagnosed and treated based on outward symptoms. That may change.
In a January paper, the American Psychiatric Association included ideas for how to incorporate biomarkers – biological indicators of mental illness that may show up on diagnostic tests – into future versions of the report. Diagnostic and Statistical Manual of Mental Disorders.
of DSMis sometimes referred to as the “Bible of Psychiatry” due to its influence in the field and provides diagnostic criteria. It is used by clinicians to evaluate patients and by insurance companies to determine whether to cover treatment.
‘Coordinated’ research needed
Psychiatric biomarkers are not yet ready for widespread use, the paper emphasizes. Scientists have been studying this topic for decades, but there has been little to show for it. The APA paper says more research is needed to prove these metrics are valid and reliable enough to be used in patient care, and other researchers say they have raised questions about how their use could impact health care costs, insurance coverage, and patient privacy.
Add a biomarker DSM Jonathan Alpert, author of the January paper and vice chair of APA’s Future DSM Strategy Committee, said this “is going to be a huge problem.”
Access to test results along with symptoms could streamline insurance coverage decisions and allow clinicians to make faster and more accurate diagnoses and treatment recommendations, he said. If a patient’s biological results suggest that they will respond better to one treatment than another, doctors can start there right away.
Matthew Eisenberg, director of the Center for Mental Health and Addiction Policy at the Johns Hopkins Bloomberg School of Public Health, said prescribing psychiatric drugs can be “a little tricky” right now, and clinicians can’t predict whether they will work for a particular patient.
In a seminal trial in the early 2000s funded by the National Institute of Mental Health, about 30% of study participants with depression had symptoms disappear after initial antidepressant treatment. The study remains one of the most powerful trials of antidepressants, but researchers have recently argued that fewer people are cured by these drugs than the results suggest.
This trial-and-error approach can lead to ineffective and unnecessary prescribing, and has been the subject of attack by supporters of the “Make America Healthy Again” movement led by Secretary of Health and Human Services Robert F. Kennedy Jr. Kennedy has been particularly critical of antidepressants, linking them to violence after mass shootings without evidence and accusing doctors of overprescribing drugs to children.
HHS spokeswoman Emily Hilliard said in a statement that HHS analyzes trends in psychiatric diagnosis and prescribing and evaluates alternative mental health treatment approaches with a particular focus on children. Mr. Hilliard did not respond to questions about Mr. Kennedy’s previous comments.
Biomarkers are already used to guide treatment in other medical fields, such as oncology. Arizona, Georgia, Kentucky, Texas and more than a dozen other states require insurance companies to pay for these tests. Blood tests and imaging tests are now also used to diagnose Alzheimer’s disease.
In its paper, APA highlighted a variety of ways in which psychiatric biomarkers could be used in the future, including testing for brain activity, genetic profiles, and immune markers associated with specific psychiatric conditions, such as schizophrenia and substance use disorders.
For example, in depression, about a quarter of patients have elevated levels of an inflammatory protein called C-reactive protein, which can be detected with blood tests. Research shows that people with high levels of this protein respond better to drugs that change dopamine levels in the brain, rather than using only selective serotonin reuptake inhibitors (SSRIs), a common type of antidepressant. The APA paper says C-reactive protein still needs to be “robustly validated” as a biomarker, but it is one of the most promising proteins currently being studied.
Achieving such validation requires a “coordinated and well-funded” research effort, APA writes, but the outlook is murky since the Trump administration cut research funding.
At the National Institute of Mental Health alone, at least 128 grants worth about $173 million were terminated in 2025, according to a research letter published in JAMA.. Although some grants have since been restored, researchers who rely on federal funding remain concerned that their research is vulnerable to cuts.
Alpert said that while “research related to mental health is in great need of continued and active funding,” scientists must contend with “uncertainty in the funding landscape.”
Ripple effects on coverage and costs
Patients with poorly controlled mental illnesses tend to have higher medical costs due to the costs of hospital visits, outpatient appointments, and prescriptions. Some studies suggest that biomarker testing may save money by finding the right treatment faster and avoiding some of these costs.
One modeling study estimates that Canada’s health-care system could save $956 million over 20 years if testing for genetic factors that can influence drug effectiveness was performed on adults with major depression in British Columbia. Another study by Spanish researchers found that such testing reduced costs for most of 188 participants with severe mental illness.
It is unclear whether the same is true for the U.S. health care system. Johns Hopkins University’s Dr. Eisenberg said that biomarker-based approaches could increase health care costs in the short term due to testing costs.
He added that insurance companies may refuse to cover expensive biomarker tests. “It takes time for new science to be proven to be safe and effective,” Eisenberg said. “And once that happens, the insurance company won’t immediately cover you.”
Some researchers have expressed concern that insurance companies and employers may discriminate against people whose biological profile suggests they are at risk for developing serious neuropsychiatric disorders.
Gabriel Lázaro Muñoz, a member of Harvard Medical School’s Center for Bioethics, said it is a “critical time” to consider legal approaches to protect patients and train clinicians on how to properly use these tools.
“I don’t think the field of psychiatry is ready to deal with this at this point,” he says.
Andrew Miller, a professor of psychiatry and behavioral sciences at Emory University School of Medicine who studies inflammation-related depression, said the mental health system is not ready to “jump in with both feet.” But APA’s adoption of biomarkers marks “the beginning of a revolution,” he said.
“This is…a recognition that what we’ve been doing hasn’t been good enough,” Miller said. “And we can do better.”
