Right now, diagnosing depression in teens isn't easy. Figuring out what's normal or not depends on a patient's willingness to report symptoms and a doctor's ability to interpret them.
Researchers at Northwestern Medicine say they have developed a breakthrough blood test that can give a more objective diagnosis.
The test was first developed by studying rats specially bred to model human depression. Then, in a small study of 28 children, scientists were able to a specify a set of genetic markers in the blood to help identify which teens were depressed and which were not.
It works much like the way cholesterol levels are tested.
Getting a teen's mental health right can be crucial because untreated depression in youth can make them more vulnerable to substance abuse, physical illness and suicide.
Eva Redie is co-author of the study..
"It's by far not replacing the psychiatrist," said Redie. "It's really augmenting. It's helping the psychiatrist to make an informed decision that in the future may help them to decide what treatments they would recommend."
Redie says there is much more research needed but that this is a good start.
There is more on the study in the journal Translational Psychiatry.