How chronic stress influences the brain and causes depression

Chronic stress affects the immune system, potentially leading to a host of health issues, including heart disease, insomnia, and even depression. In fact, many stress-related mental illnesses are linked to changes in the immune system. But it remains unknown how the immune system could cause such behavioral changes like depression. How do changes in the immune system affect the brain?

How chronic stress may lead to depression

Researchers from the University of Zurich have discovered that chronic stress causes a particular enzyme in the immune system to enter the brain, affecting neurons and causing the individual to withdraw and display social avoidance, signs of depression. This enzyme is known as matrix metalloproteinase-8 (MMP-8).

When MMP-8 travels through the blood under stress to the brain, it alters the functioning of some specific neurons.

"We were able to show that stress increases the amount of the matrix metalloproteinase-8," says study author Flurin Cathomas, "an enzyme in the blood of mice. The same changes were found in [human] patients with depression."

These changes lead to social withdrawal and avoidance, which is a symptom of depression.

This is a new discovery as regards how chronic stress and the immune systems affect the brain and lead to depression. If the substance responsible (the enzyme in this case) has been identified, then this can present opportunities for developing more targeted treatments for depression.

More on the research here.

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Depression can be quite complex. For most patients, they do not exactly know why they feel the way they do. They just know nothing makes sense anymore. If that's your situation, or you know a loved one battling depression, we want to help. We have a range of treatment options, and we will recommend what's best for your unique situation.

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Author

Satu H. Woodland, PMHCNS-BC, APRN Satu Woodland is owner and clinician of Hope Mental Health, an integrative mental health practice located at Bown Crossing in Boise, Idaho. She sees children, adolescents, and adults.  Ms. Woodland with her background in nursing, prefers a holistic and integrative approach to mental health care that addresses the mind and body together. While Ms. Woodland provides medication management services in all her patients, she believes in long-lasting solutions that include a number of psychotherapies, namely cognitive behavioral therapy, exposure and response prevention therapy, attention to lifestyle, evidenced based alternative psychiatric care and spirituality. If you’d like to gain control over your mental health issues, call Hope Mental Health at 208-918-0958, or use the online scheduling tool to set up an initial consultation.