Depression Causes

People who experience depression are usually more focused on treating the condition than finding its cause. But new research is beginning to shed light on both the triggers for depression and how to alleviate it.

Depression affects one in 10 Americans at some point in their lives, and the number of patients diagnosed with depression goes up by about 20 percent each year. The World Health Organization says it is the top cause of disability worldwide, and that five to seven percent of people on Earth experience a major depressive episode in a given year.

As science evolves and more people speak out about the issue, we’re finding that depression has more root causes than anyone suspected.


Cause: Concussions

A new study in the Journal of Adolescent Health recommends that doctors screen teens with a history of concussion, as they are three times more likely to suffer from depression. Researchers evaluated data from 36,000 adolescents; of them, 2.7 percent had a concussion and 3.4 percent experienced depression.

According to the Centers for Disease Control and Prevention, 1.6 to 3.8 million sports- and recreation-related concussions occur each year in the U.S. Moreover, a mild brain injury occurs every 21 seconds, so screenings are crucial.

Cause: Chronic Stress

A research team at the Hebrew University of Jerusalem found that changes in one type of brain cell, called microglia, indicate depressive symptoms brought on by exposure to chronic stress. Microglia make up about 10 percent of brain cells and represent the immune system in the brain. They are also involved in physiological processes that have nothing to do with infection or injury—such as the body’s response to stress, research has shown.

The Israeli researchers were able to demonstrate in animals that compounds which alter the function of microglia make efficient drugs. The findings were published in Molecular Psychiatry.

Raz Yirmiya, a professor at the university, said the research shows that disturbances in microglia cells play a role in causing psychopathology in general and depression in particular.

“They may be able to help people get symptom relief faster,” said Amy Morin, a therapist from Maine, who said this could be great news for people who are experiencing a loss of day-to-day function due to depression. 

“Waiting four to six weeks to see if an anti-depressant is working can be fatal for people who experience suicidal ideation as part of their depression,” she added.