Identifying biomarkers such as changes in brain function for the treatment of depression is difficult due to the different symptoms experienced by those affected. However, a research team – led by Professor Dr Nils Kroemer of the University Hospital Tübingen as well as the University Hospital Bonn (UKB) and the University of Bonn has investigated whether it is possible to draw conclusions about the direction appetite changes – increase or decrease. – based on the functional structure of the reward system in the brain.
. A variety of changes in motivation, emotions, and physical experiences are characteristic of this disorder. Many depressed patients not only lose interest in rewarding activities, but also experience cravings. At the same time, other patients reported increased appetite during the depressive episode. To date, not much is known about the causes of these differences in symptoms in depression and how they can be specifically treated.
A team of researchers led by Professor Dr. Nils Kroemer, who works in the Translational Psychiatry Unit of the Department of Psychiatry and Psychotherapy at the University Hospital Tübingen, and Professor of Medical Psychology in the Department of Psychiatry and Psychotherapy. at Bonn University Hospital, it is now possible to gain new insights into the topic as part of a multicenter study. Using magnetic resonance imaging, the researchers showed that the direction of changes in appetite associated with depression is linked to specific changes in the brain’s reward system.
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For a long time, scientists like Professor Kroemer’s group have been looking for shared changes in the reward system in depressed patients. This idea is intuitive because depressed patients often experience striking changes in their motivation. “But the idea of a ‘depressive’ reward system seems to be more of an illusion,” explains Kroemer, lead author of the study.
“Instead of looking for general changes in the reward system, we can better relate specific changes, such as food cravings and body weight, to differences in the brain that help solve the problem.” prefer individual symptoms.”
About research
The team, which included researchers from several German university hospitals, examined the brain function of the participants affected at rest and recorded their psychological symptoms. This allowed them to compare whether individual depressive symptoms were more predictable. To do this, they focused on the functional connectivity (also called connectivity strength; it describes the strength of communication between different brain regions) of the nuclei, one of the central regions of the brain. focus on reward processing and goal-directed behavior control, with the other brain. region.
When depressed patients with anorexia nervosa were in a depressive episode, the strength of the association between the reward system and other regions that play an essential role in value-based decisions and memory processes was reduced. On the other hand, if there was an increase in appetite, the researchers observed a weaker link between the reward system and the part of the brain that processes taste stimuli and bodily cues.
Kroemer describes the study results: “These changes in the reward system are so prominent in cases of major depression that we can predict whether someone will experience increased or anorexia based on individual profiles. of the reward system. “Conversely, it’s impossible to tell if someone is depressed in general. So it’s not just about the change, but especially the nature of the behavior change.”
More targeted therapy options are needed
As there is no universal pattern of changes in the reward system in depression, the study points to the potential of precision medicine. These new approaches focus not on the general diagnosis but on individual symptoms. With the help of such symptom-based changes in the brain, it will be possible to develop targeted therapies that directly address the specific symptoms of those affected in the future.
For this reason, Kroemer’s research team is planning further research into innovative treatments using neuromodulatory approaches such as brain stimulation. The aim is to investigate how certain symptoms are caused by changes in the brain and whether they can be reversed using individualized neuromodulatory therapies.
References:
1. The functional connectivity of the reward circuit predicts changes in appetite during depression – (http://dx.doi.org/10.1001/jamapsychiatry.2022.2464)
Source: Eurekalert
