People with depressive disorder may have faulty neural processing of sensations like hunger or satiety, new study says.
Interoception is the ability to recognize the stimuli and sensations sent by the body, a sort of sixth sense . Previous studies have shown that interoception is reduced in people with depression, but new brain scans are showing how circuits involved in what have been termed ‘gut sensations’ can be altered in people with repetitive negative thoughts.
“Repetitive negative thinking ( RNT ), usually referred to as ruminative in people with depression, is a very significant clinical problem,” said recent study author Salvador M. Guinjoan. Our body constantly monitors through interoception our internal needs to know if we are hungry, thirsty and more. It’s a vital part of maintaining the body, and disruptions can be debilitating.
Previous studies have found that faulty interoception could be related to lower learning outcomes in people with depressive disorder, but it was not yet clear how this could happen and whether this could be associated with other needs, such as hunger.
The focus of the new study is particularly on repetitive negative thinking RNT: people prone to RNT often dwell on their shortcomings , may have low self-esteem due to negative thoughts about themselves and generally place much more importance on the aspects negatives in their life.
The researchers collected data on 48 people with depression with high RNT scores and 49 people with depression with low RNT scores, as well as a group of 27 non-depressed people as a control group.
Participants were asked to focus on sensations coming from their heart and stomach as the scientists looked at their brains through functional magnetic resonance imaging scans. In this way, it was possible to verify the differences between people without depressive disorders and those with a high RNT and the way their brain works during interception.
All depressed people have reduced processing of signals from the stomach, and this happened in different regions of the brain. Most interesting, however, was the fact that people with high RNT had an even greater reduction in the processing of signals from the stomach, which was particularly concentrated in the brain regions responsible for processing emotions and memory.
These findings could help explain why people with a high rate of repetitive negative thoughts often report abdominal problems, as signals from the stomach aren’t processed in the typical way. The researchers hope that further investigations can be conducted in this area to help improve treatment outcomes in patients with high RNT scores.
- Attenuated interoceptive processing in individuals with major depressive disorder and high repetitive negative thinking. (sciencedirect.com)