Uncovering the biological root of depression and suicide

September is National Suicide Prevention Month, a time to raise awareness

Each year, an estimated 300 million people worldwide will experience depression, making it one of the most common health problems on a global scale.

At its most severe, depression can lead to suicide, which is responsible for more than 800,000 deaths annually, according to the World Health Organization.

“Unfortunately, there still is a social stigma around depression, which can discourage people from seeking help or speaking openly about it,” said Dr. Lena Brundin, a physician-scientist in Van Andel Research Institute’s Center for Neurodegenerative Science. “It is important to realize that depression is more than a feeling of sadness—it is rooted in biology. Understanding this fact is a crucial step toward prevention and new strategies for care.”

What is depression?
Depression differs from the usual ups and downs that are part of everyday life. It is caused by a complicated mix of psychological, social and biological factors that vary from person to person.

There are many types of depression, but they share several common symptoms, including a sustained feeling of malaise, loss of interest and a lack of energy. Some people may also experience anxiety, trouble sleeping and loss of appetite.

Mounting evidence suggests that inflammation may be an important trigger for depression.

What is inflammation?
Inflammation is the body’s reaction to a harmful stimulus, such as infection with a virus like the flu or an injury like a cut. Although it is a normal and important part of our natural defenses, it’s more of a bandage rather than a long-term solution.

Inflammation occurs when the body releases a cascade of chemicals that marshal to our aid, attempting to remove the cause of the problem and start the healing process. The results, though designed to help us, aren’t always pleasant. They can include increased blood flow, leading to redness and increased heat; fluid rushing to the area, causing swelling; and pain, the result of a flood of chemicals to stimulate nerves.

Occasionally, the body overproduces inflammatory chemicals or continues producing them long after it should have stopped, which can lead to a number of problems.

How are inflammation and depression related? What does this mean for treatment?
Chronic inflammation can wreak havoc throughout the body. It has long been known to play a part in many diseases, such as arthritis and cancer, and, more recently, has been linked to others, including depression.

“Our bodies are in a constant balancing act. Occasionally, it tips too far in the wrong direction,” Brundin said. “Many existing medications combat inflammation and help to restore this balance, in part. It is our belief that one of them may also provide new hope for people with depression.”

Certain inflammatory chemicals also may offer new ways to diagnose and track depression and suicide risk. In a study published last year, Brundin and her collaborators found that levels of an enzyme called ACMSD varied between people who had a history of suicide attempts and those who did not. Given its role as a key regulator of inflammation, ACMSD may be an important target for future treatments as well as a potential indicator of suicide risk.

“We’re making significant inroads into understanding how inflammation impacts depression and suicide risk,” Brundin said. “We’re hopeful that our findings and those of our colleagues will one day lead to improved care strategies for people battling this devastating condition.”

September is National Suicide Prevention Awareness Month, with September 10 designated as World Suicide Prevention Day. For more information on suicide prevention, please visit the National Institute of Mental Health’s website here. The toll-free National Suicide Prevention Lifeline is available 24/7 and may be reached at 1-800-273-TALK (8255).