Major Depressive Disorder is associated with impaired interoception – or the ability to sense the internal state of your body. Now, new brain imaging research provides evidence that depressed people tend to exhibit “defective” neural processing of gastric interoception, particularly in those with high levels of rumination. The findings were published in the Psychiatric Research Journal.
“Repetitive negative thinking (RNT), generally referred to as ‘rumination’ in people with depression, is a very important clinical problem,” explained study author Salvador M. Guinjoan, lead researcher at the Brain Research Institute Laureate and associate professor at the University of Oklahoma Health Sciences Center in Tulsa.
“The reason for this is that when severe and persistent, RNT conditions the chances of relapse of depression and is associated with residual symptoms after treatment, is more common in people who do not respond to treatment and is even related to suicide This particular paper refers to one of a series of projects in our lab attempting to understand rumination.
“In a previous communication, we reported that high rumination is associated with low emotional learning abilities,” Guinjoan said. “And one possible mechanism for this to happen was that interoceptive feedback (i.e. the body’s information conveying emotion) was defective in people with depression.”
The study included 48 depressed people who scored high on the Ruminative Response Scale and 49 depressed people who scored low on the scale. People who score high on the scale report that they frequently engage in various types of rumination, such as thinking about their shortcomings, thinking about how lonely they feel, and thinking “Why do I always react in this way?” The researchers also recruited 27 healthy volunteers, who served as a control group.
To assess neural correlates of interoceptive awareness, participants were instructed to selectively attend to sensations coming from their heart and stomach while researchers used functional magnetic resonance imaging technology to monitor their brain activity. .
Compared to controls, depressed individuals exhibited reduced central processing of interoceptive information from the stomach in several regions of the brain, including the left medial frontal region and insular cortex, perirhinal cortex, and caudate nucleus. This was true regardless of the level of rumination.
However, depressed individuals with high levels of rumination additionally exhibited reduced processing of gastric sensations in the hippocampus, amygdala, and entorhinal cortex. These brain regions play a key role in memory, emotional information processing and perception.
“We observed that people with depression have a problem with the central processing of interoceptive information that specifically comes from the gut, in relation to a greater tendency to ruminate,” Guinjoan told PsyPost. “We hypothesize that in this context, interoceptive information provides insufficient or defective feedback on emotion perception and learning, which in turn may prevent the highly ruminative person with depression from stopping repetitive thoughts. and negatives.
The researchers were surprised to find that the abnormalities in neural processing of interoception were limited to the stomach.
“We kind of expected the interoceptive abnormalities to be more prominent in the territory of the heart,” Guinjoan explained. “But it turned out that the interoception of the stomach was more compromised. In hindsight, this makes sense because many people with depression actually have symptoms referred to the abdomen, including patients who see a primary care physician or gastroenterologist because of their abdominal problems.On the other hand, people with anxiety seem to focus more on the cardiovascular system.
The study, “Attenuated interoceptive processing in people with major depressive disorder and high repetitive negative thinkingwas written by Heekyeong Park, Stella M. Sanchez, Rayus Kuplicki, Aki Tsuchiyagaito, Sahib S. Khalsa, Martin P. Paulus, and Salvador M. Guinjoan.