If you’re having chest pain, your doctor can test you for a heart attack. If you’re having hip pain, your doctor could test for osteoarthritis.
But what if you’re depressed? Or anxious? Currently there are no physical tests for most disorders that affect the mind. Lab tests like these could transform the field of mental illness. So far efforts to come up with biomarkers for common mental health disorders have proved largely fruitless.
That doesn’t stop people from trying. Doctors are looking to create them, and patients are taking them, too, even though they know that existing biomarkers — for Alzheimer’s disease, for instance — have serious limitations.
by Amy Standen, NPR