tiny molecule cause of depression tiny molecule cause of depression Scientists are researching the root of depression and other mental disorders. (Photo: Evgeny Atamanenko/Shutterstock)

Micro-molecule could help treat mood disorders

Researchers discover how a tiny molecule causes depression and anxiety disorders – and the role it could play in treating them.

One-tenth of the world's population suffers from mood disorders like depression and bipolar disorder, but for many, antidepressant medication offers little to no relief. Professor Alon Chen of Israel's Weizmann Institute of Science sought to better understand the root of such disorders to create more effective medications and told From The Grapevine how his team discovered the inner workings of a molecule that could lead to new forms of treatment.

"Depression is the most common mental disorder and affects all aspects of a person's life; relationships with family and friends, productivity at work, and an impaired sense of self," said Dr. Alyssa Berlin, a clinical psychologist, co-founder of Berlin Wellness Group, who did not participate in the study.

Depression and anxiety have been linked to misregulated serotonin systems in the brain, so Chen and his team investigated the role that microRNA molecules play in the nerve cells that produce serotonin. For the first time, they were able to identify the unique characteristics of a particular microRNA molecule that affects serotonin-producing nerve cells.

"Although we have numerous treatment options available and have seen tremendous success utilizing psychotherapy and psychopharmacology, there is still a lot we don't know about this disorder and a sub-sect of the population that doesn't respond well to standard treatment, and appear to struggle with Treatment-Resistant Depression," said Berlin.

The researchers found that the levels of the miR135 molecule increased when antidepressant medications were introduced. Mice that were genetically engineered to produce higher-than-average amounts of microRNA were found to be more resistant to constant stress, while mice that had low levels of microRNA were more prone to develop stress-related mood disorders and were also less responsive to antidepressant medication.

The research suggests that the brain needs the correct amount of miR135 – high enough to avoid depression, but low enough to form a healthy stress response.

The team tested its hypothesis on human blood samples and discovered that blood drawn from subjects who suffered from depression had unusually low levels of miR135.

“Our finding strongly suggests miR135 as possible treatment for mood and anxiety disorders,” Professor Chen told From The Grapevine. “The big challenge now is to deliver this miR135 mimetic into the brain.”

Chen said current research is being focused on the development of the miR135 mimetic, which could result in more effective treatments for people who are not responding to already available medications.

"The research coming out of the Weizmann Institute is exciting and I am optimistic that this new development will help deepen our understanding of this disorder enabling us to treat a larger proportion of the population struggling with depression," said Berlin.


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Micro-molecule could help treat mood disorders
Researchers discover how a micro-sized molecule causes depression and other mood disorders – and the role it could play in treating them.