It is not uncommon for many people to think about a problem from many angles. But ruminating or brooding can become unproductive or detrimental to making good life choices.
Non-productive ruminations are a common symptom of depression and can be annoying or paralyzing. In fact, individuals suffering from depression often ruminate about being depressed. This ruminative thinking can be either passive or maladaptive (i.e., worrying) or active and solution-focused (i.e., coping).
In a new study, Stanford University researchers attempted to determine now these types of rumination are represented in the brains of depressed people.
The findings are published in the journal Biological Psychiatry.
Scientists discovered two distinct and competing neural networks are responsible for the different types of ruminations.
The default mode network (DMN) supports passive, self-related thought while the task positive network (TPN), underlies active thinking required for solving problems, said study author J. Paul Hamilton, Ph.D.
Using brain imaging technology, Hamilton and his colleagues found that, in depressed patients, increasing levels of activity in the DMN relative to the TPN are associated with higher levels of maladaptive, depressive rumination and lower levels of adaptive, reflective rumination.
These findings indicate that the DMN and TPN interact in depression to promote depression-related thinking, with stronger DMN influence associated with more worrying, less effective coping, and more severe depression.
“It makes sense that non-productive ruminations would engage default-mode networks in the brain as these systems enable the brain to ‘idle’ when humans are not focused on specific tasks,” commented Dr. John Krystal, editor of Biological Psychiatry.
“Better understanding the factors that control the switch between these modes of function may provide insights into depression and its treatment.”