Scientists Find Biomarkers for Depression

Scientists believe they have discovered a biomarker for depression. This finding may lead to blood tests that can determine the effectiveness of various antidepressants as early as a week after the start of treatment.

In a small proof-of-concept study, researchers took blood samples from 41 patients with major depressive disorder and compared them to 44 controls without depression, a biomarker that could track the disorder. Was separated.

“We have developed a test that can not only show the presence of depression, but also a therapeutic response with a single biomarker, which has never existed before,” he said. Professor Mark Rasenick of the University of Illinois said. Illinois Chicago and Research Leader, Said in a press release.

Previous studies have shown that people with depression also have reduced adenylate cyclase. Adenylate cyclase is present in almost every cell and is part of a complex process that signals neurotransmitters such as serotonin and epinephrine.

“When you’re depressed, adenylate cyclase is low,” Rasenick said. “The reason adenylate cyclase is attenuated is that Gsalpha, an intermediate protein that allows neurotransmitters to make adenylate cyclase, is well packed in a cholesterol-rich membrane matrix (lipid raft). Because it doesn’t work. “

In a new study published in the January edition of the journal Molecular Psychiatry, researchers identified a cellular biomarker (shift of protein Gsα from lipid rafts) that indicates depression. They say that this biomarker can be found on a blood test.

Researchers obtained data from a 6-week study of patients experiencing acute major depressive episodes who agreed to be part of the study. Patients were found in a study from September 2013 to May 2016 and compared to a control group with no history of depression.

In this study, blood samples were taken from patients at least two instances at weekly intervals. On the second visit, patients who wanted to take medication to treat depression were prescribed antidepressants after consulting with a research psychiatrist.

These patients were followed up after 6 weeks to evaluate their symptoms and draw more blood.

Researchers have specifically focused on platelets in the blood, where they found biomarkers.

This study found that patients with depression were “significantly lower.” […] “Activation of adenylate cyclase activity in platelet samples” was more responsive to antidepressant treatment than in healthy controls. […] Comparison of “adenylate cyclase” at 6-week check-in with those who did not respond to the antidepressant treatment they were receiving.

This supported a previous study in which it was found that the Gs alpha protein was transferred from lipid rafts when patients taking antidepressants reported improvement in depressive symptoms. However, patients taking antidepressants who did not improve their symptoms remained trapped in lipid rafts with Gsalpha.

Some antidepressants can be life-changing, but they can take months to see their effects, and they need to go through a thorough process of testing different types to find one that works. There may be.

If a blood test can show whether the Gs alpha protein is shifting out of the lipid raft as an indicator of drug success, it may help streamline the process of finding an effective drug for an individual patient. .. Many antidepressants are on the market.

“Platelets turn over in a week, so there are changes in people who get better,” Rasenick said. “You can see biomarkers that predict the success of the treatment.”

It may also identify which patients will benefit from the medication to treat depression and which patients will need other means to relieve their symptoms.

Rasenick hopes to develop a screening test with his company, Pax Neuroscience, in the future if further research is successful.

“About 30% of people don’t get better — their depression doesn’t go away. Perhaps failure causes failure, assuming that both the doctor and the patient do nothing,” Rasenick said. .. “Most depression is diagnosed in the clinic of an unscreened primary care physician. With this test, the doctor can say, so this may need to be revisited. not.”

Researchers have pointed out in the study that they lack the placebo group, so it is not entirely established whether antidepressants caused an increase in adenylate cyclase. This study is also limited due to its narrow scope, and researchers hope to conduct larger studies in the future, including studies that can compare different types of antidepressants. ..