People with major depressive disorder (MDD) experience more intense negative emotions while recalling painful memories compared to non-depressed people, according to a new study published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
And although those with MDD were able to turn down their negative emotions about as well as non-depressed people, they used different brain circuits to do so.
The new findings pinpoint brain differences in MDD associated with the processing of autobiographical memories — one’s memories of personal events and knowledge of one’s life — that help us develop our sense of self and guide our interactions with the world around us.
“This study provides new insights into the changes in brain function that are present in major depression,” said journal editor Cameron Carter, M.D. “It shows differences in how memory systems are engaged during emotion processing in depression and how people with the disorder must regulate these systems in order to manage their emotions.”
The study involved 29 men and women with MDD and 23 healthy people as controls. The researchers used participants’ personal memories to help evoke emotion. This allowed the researchers to tap into the complex emotional situations that people with MDD experience in their daily lives.
The findings reveal that the MDD participants experienced higher levels of negative emotions while recalling their painful memories compared to the healthy comparison people.
Using brain imaging, senior author Kevin Ochsner, Ph.D., of Columbia University, and colleagues were able to trace the stronger emotional reactions to increased activity in the amygdala, the emotional hub of the brain, and to interactions between the amygdala and the hippocampus, a brain region associated with memory.
Importantly, however, the MDD participants were able to turn down these increased negative emotions to normal levels while recalling the memory from the position of a distant observer.
“When they were using this strategy, people with MDD showed a pattern of brain activity that was comparable to what was shown by the healthy controls, with one key difference — greater dampening of a region of posterior hippocampus that has been associated with recalling specific memory details,” said lead author Bruce Doré, Ph.D., of the University of Pennsylvania.
The findings suggest that while negative memories have a stronger emotional impact on people with MDD, they may be able to manage their emotional response by making it harder to remember specific details of the experience.
“This is generally consistent with a growing body of work suggesting that people with MDD are able to regulate their emotions when instructed to, but they may tend towards doing so in an abnormal manner, such as being more likely to use problematic strategies like distraction and rumination in daily life,” said Doré.
This type of research is supports the notion that people with MDD could benefit from training that focuses on identifying and effectively using appropriate strategies for emotion regulation, added Doré.
“It is possible that training could help to normalize the MDD-related functional brain differences that we observed here,” he said.