A new blood test designed at Massachusetts General Hospital appears to accurately indicate whether a person is suffering from depression, according to a paper published in Molecular Psychiatry.

Depression, a psychological disorder currently diagnosed by matching a certain number of patient symptoms to those listed in the Diagnostic and Statistical Manual, has been known to have physiological indicators. According to George I. Papakostas, the primary researcher for the new test at MGH, after more than 50 years of experimenting with depression there were still many questions about the biological signals of the disorder.

“There were signs, but not strong enough for a test,” said Papakostas, who is also a professor of psychiatry at Harvard Medical School.

He and the other researchers in his lab wondered, “what if the solution is multi-faceted?”

After a series of experiments, a blood test was designed to measure the level of nine different chemicals shown to be associated with depression. According to Papakostas, when the results of the blood tests were compared to the diagnoses of a trained clinical psychologist, the blood test proved to be surprisingly accurate.

The test is designed to be simple, Papakostas said. The patient comes in for a regular blood draw and then the blood is sent to a lab for testing.

The results of this test are translated into a point system that indicates whether a patient is likely suffering from depression.

According the Papakostas, the most important implications of this discovery are the new questions it raises and its potential applications. He and his researchers are now asking whether it can be used to monitor the recovery of a patient suffering from depression, find patients who have a potential to be depressed, or indicate that a patient is likely to relapse into depression. However, the question currently at the forefront for Papakostas is whether or not this test is effective in screening subjects in a doctor’s clinic.

Papakostas said the test will undergo further study, this time in a clinical field, to gauge how effective it is in the real world. He hopes it will become a helpful tool for diagnosticians and a clue to help researchers better understand depression.

Papakostas does not see this test as a new standard for clinical diagnosis.

“Testing negative is not a reason for insurance companies to not cover the expenses of treatment or reason to absolutely reject depression as a diagnosis,” said Papakostas. “The test is supposed to complement clinical care.”

—Staff writer Armaghan N. Behlum can be reached at behlum@college.harvard.edu.