Depression is often like being sunken in a deep hole. Unable to reverse negative, spiraled thinking, people who suffer from depression feel as though they’ll be stuck in the same place forever. Making changes, or even doing daily activities like getting out of bed and brushing your teeth, can feel like walking through mud. One major feature of depression involves “rumination,” or the tendency to focus primarily on feelings of guilt, shame, or self-deprecation.

New research examines the brain mechanisms behind rumination, focusing mainly on the subgenual prefrontal cortex (sgPFC) in the brain and another area in the brain, the default mode network (DMN), which is typically associated with reflection. The researchers, from the Laureate Institute for Brain Research and Stanford University, wanted to explore how the relationships between these brain regions were tied to depressive ruminations.

They reviewed existing studies, and found that these depressive ruminations were more likely to appear in depressed patients when the sgPFC’s activation was closely coordinated with that of the DMN. This connectivity is what increases ruminating thoughts, the authors concluded.

“This study shows that depression distorts a natural process,” said Dr. John Krystal, editor of Biological Psychiatry, in a press release. “It would seem that normally the subgenual prefrontal cortex helps to bias the reflective process supported by the default mode network so that we can consider important problems in the service of developing strategies for solving them. However, in depression, it seems that the subgenual prefrontal cortex runs amok hijacking normal self-reflection in a maladaptive way.”

Despite many people still holding onto a stigma about depression, it is a real, biological disease with roots in brain chemistry and activity. These negative, spiraling thoughts have a long-term toll on physical, mental, and emotional health: they leave no room to think and impair memory; can make patients feel fatigued and anxious; and impair cognitive ability.

But there are numerous ways to combat depression and its accompanying ruminating thoughts. Practicing mindfulness and meditation has been shown to be just as effective as cognitive behavioral therapy in treating depression and anxiety, and daily exercise can improve cognitive function as well as boost “happy endorphins” like serotonin and dopamine.

Source: Hamilton J, Farmer M, Fogelman P, Gotlib I. Depressive Rumination, the Default-Mode Network, and the Dark Matter of Clinical Neuroscience. Biological Psychiatry, 2015.