Almost 50% of psychiatric patients get a change in diagnosis over a 10-year period—meaning they may end up taking a slew of unhelpful drugs until doctors finally decide what mental illness they have. But what if a simple blood test could help discern whether patients have schizophrenia, major depression, or bipolar disorder? Rules-Based Medicine, a company that specializes in research and development for drugs and diagnostics, thinks it can.
Six months ago, the company launched VeriPsych, the first blood test for schizophrenia. The test, developed in conjunction with Cambridge University, relies on 51 biomarkers in the blood that are associated with schizophrenia (pathways are for inflammation, metabolism, cell-to-cell signaling, and more) according to samples of blood from patients with a confirmed diagnosis. It is a protein-based test in the blood—not a genetic test signaling that you have a risk of the disease.
Since its launch, psychiatrists have ordered the test for approximately five hundred patients. That's not an unexpectedly low number, explains Dr. Michael Spain, the Chief Medical Officer for VeriPsych. "There's not so much resistance as trepidation. Physicians that routinely do lab tests understand that [the doctor] puts it all together and makes the diagnosis. Psychiatrists have it in their minds that the test makes the diagnosis," he says.
The VeriPsych team has tried to rule out the possibility that biomarkers used in the test are actually the result of, say, drugs used to treat schizophrenia. That would mean anyone who has taken drugs for the disease would have the biomarkers. "The advantage of working with Cambridge is they had access to three German academic centers that had significant numbers of drug-naive schizophrenics that have never been treated," says Spain. That's hard to find in the U.S., where schizophrenics are often treated with a variety of drugs before finally making it into a psychiatrist's office.
Schizophrenics are also diagnosed relatively young (average age of diagnosis is 21), so there is less of a chance that the biomarkers could be the result of other diseases. A similar blood test for Alzheimer's would have to rule out the possibility that the biomarkers are related to heart disease, Type 2 diabetes, or other issues that arise as people age.
Schizophrenia is just the beginning for VeriPsych. By the end of 2011, Spain and his team will have a differential blood test for major depression and schizophrenia ready for the market. Next year, they plan to add bipolar disorder into the mix. VeriPsych and Rules-Based Medicine may have more success with these tests, simply because depressive and bipolar patients are often treated in primary care facilities, where doctors are comfortable using blood tests for diagnosis. The depression market is also 10 times the size of the schizophrenia market—13 million people in the U.S either carry the diagnosis or soon will.
At the very least, these blood tests stand to change the way we think about mental illness. "These are systemic diseases," Spain says. "It's just that the main symptoms come from the brain."