When previously depressed individuals enter mild states of sadness, their brain’s response can predict if they will sink into depression again, according to researchers at the University of Toronto.
“Part of what makes depression such a devastating disease is the high rate of relapse,” said Norman Farb, a Ph.D. psychology student and lead author of the study.
“However, the fact that some patients are able to fully maintain their recovery suggests the possibility that different responses to the type of emotional challenges encountered in everyday life could reduce the chance of relapse.”
For the study, researchers used functional magnetic resonance imaging (fMRI) to track the brain activity of 16 formerly depressed patients as they watched sad movie clips. Sixteen months later, after nine of the 16 patients had relapsed into depression, the team compared the brain activity of the relapsed patients against those who remained healthy as well as a control group who had never been depressed.
The images showed that when faced with sadness, the relapsing patients displayed more activity in the medial prefrontal gyrus, located in the front of the brain. This response is linked to higher rumination: the tendency to think obsessively about negative events.
The patients who did not relapse displayed more activity in the back part of the brain, an area that is responsible for processing visual information and is associated with stronger feelings of acceptance and non-judgment of experience.
“Despite achieving an apparent recovery from the symptoms of depression, this study suggests that there are important differences in how formerly depressed people respond to emotional challenges that predict future well-being,” said Farb.
“For a person with a history of depression, using the frontal brain’s ability to analyze and interpret sadness may actually be an unhealthy reaction that can perpetuate the chronic cycle of depression. These at-risk individuals might be better served by trying to accept and notice their feelings rather than explain and analyze them.”
The research is published in Biological Psychiatry.
Source: University of Toronto