Summary: According to researchers, people who suffer from major depressive disorder may report feeling more negative emotions when recalling specific autobiographical memories.
People with major depressive disorder (MDD) feel more negative emotion when remembering painful experiences than people without the disorder, according to a new study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. The study reports that people with MDD were able to control the negative emotions about as well as people unaffected by MDD, but used somewhat different brain circuits to do so. The findings identify brain differences in MDD related to processing of autobiographical memories, the memories of the events and knowledge of one’s life, that help us form our self-identity and guide our interactions with the world.
“This study provides new insights into the changes in brain function that are present in major depression. 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,” said Cameron Carter, MD, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
The personal memories used to evoke emotion in the study help tap into complex emotional situations that people with MDD experience in their daily lives. The 29 men and women with MDD included in the study reported higher levels of negative emotions when bringing negative memories to mind than 23 healthy comparison people. Using brain imaging, senior author Kevin Ochsner, PhD, of Columbia University and colleagues traced the elevated emotional responses to increased activity in an emotional hub of the brain, called the amygdala, and to interactions between the amygdala and the hippocampus–a brain region important for memory.
People with MDD were able to tune these increased negative emotions down to normal levels when recalling the memory as 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, PhD, of University of Pennsylvania.
The findings suggest that although negative memories have a stronger impact on people with MDD, they may be able to regulate 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 Dr. Doré.
According to Dr. Doré, this kind of work is consistent with the notion that people with MDD could benefit from training that focuses on identifying and effectively using appropriate strategies for emotion regulation. “It is possible that training could help to normalize the MDD-related functional brain differences that we observed here,” said Dr. Doré.
Source: Rhiannon Bugno – Elsevier
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Original Research: Abstract in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Negative autobiographical memory in depression reflects elevated amygdala-hippocampal reactivity and hippocampally-associated emotion regulation
Dysregulated autobiographical recall is observed in Major Depressive Disorder (MDD). However, it is unknown whether people with MDD show abnormalities in memory-, emotion- and control-related brain systems during reactivity to and regulation of negative autobiographical memories.
We used fMRI to identify neural mechanisms underlying MDD-related emotional responses to negative autobiographical memories and the ability to down-regulate these responses using a cognitive regulatory strategy known as reappraisal. We compared currently depressed, medication-free patients with MDD (n = 29) to control participants with no history of depression (n = 23).
Relative to healthy controls, medication-free MDD patients reported greater negative emotion during recall but relatively intact down-regulation success. They also showed elevated amygdala activity and greater amygdala-hippocampal connectivity. This connectivity mediated the effect of MDD on negative emotional experience. When reappraising memories (versus recalling from an immersed perspective), MDD and control groups showed comparable recruitment of prefrontal, parietal, and temporal cortex, and comparable down-regulation of amygdala and anterior hippocampus. However, MDD patients showed greater down-regulation of posterior hippocampus, and the extent of this down-regulation predicted successful reduction of negative affect in MDD patients only.
These data suggest amygdala-hippocampal connectivity and posterior hippocampal down-regulation as brain mechanisms related to elevated emotional reactivity and atypical emotion regulation in MDD.