Do you constantly replay or obsess over negative situations? This disposition, known to the world of psychology as rumination, can feel like a broken record. Even in a day that is filled with accomplishments and positive events, people with this disposition will hyperfocus on one negative event of the day, such as getting yelled at by a boss. This type of rumination, in turn, can impact individuals to the point where it detracts from their ability to perform daily activities.
Although the propensity for rumination in depressed individuals has been heavily documented, a new study by Dr. J. Paul Hamilton at the Laureate Institute for Brain Research and his colleagues at Stanford University suggests that they have found the brain mechanism that gives rise to these thoughts.
In a brilliant move, Dr. Hamilton and his colleagues highlighted the interplay between the subgenual prefrontal cortex (sgPFC), the brain region implicated in depression, and the Default Mode Network (DMN), the region of the brain associated with reflection. It is well known that the DMN is activated when the brain’s task-oriented circuits are not engaged, or during times of self-reflection.
By reanalyzing existing studies, Hamilton and colleagues show that depressive ruminations are more likely to emerge in depression when the firing of the sgPFC, signaling depressed mood, is more tightly coordinated with the firing of the DMN. They propose that the observed increased connectivity reflects a functional integration of sgPFC and DMN processes, which in turn, support rumination in depression.
Image Source: Tara Moore
“This study shows that depression distorts a natural process. 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,” commented Dr. John Krystal, Editor of Biological Psychiatry. Dr. John continued, declaring that he believes that depressive rumination is the result of the subgenual prefrontal cortex running amok, “hijacking” normal self-reflection in a maladaptive manner.
By discovering this relationship between the sgPFC and the DMN, Dr. Hamilton and his colleagues have discovered an angle of attack to dispel one of the most deleterious symptoms of depression. As is the case with all diseases, one of the major obstacles to overcome is pinpointing its underlying mechanisms, and Dr. Hamilton and his colleagues believe they have done just that.
Feature Image Source: Rumination by Ivana Vasilj