Recent research has revealed how short-term fasting can improve mood in patients with major depressive disorder. The study focused on the role of ghrelin, a hormone produced in the stomach that affects mood and appetite. The survey results are Psychiatric Research Journalhave shown that increased ghrelin concentrations after fasting are associated with improved mood, especially in depressed patients who are not taking medication.
Major depressive disorder is a widespread mental health condition characterized by persistent feelings of sadness, hopelessness, and lack of interest or enjoyment in most activities. These symptoms significantly impair daily functioning and quality of life.
This research was motivated by growing interest in how metabolic signals from the body, particularly the gut, influence mental health. Ghrelin, a hormone produced in the stomach, has been shown to play a role in regulating appetite and energy balance. However, recent research suggests that ghrelin may also influence mood and stress responses.
Previous studies on the role of ghrelin in depression have produced mixed results, with some studies showing that higher ghrelin concentrations may improve mood, while others found no significant effect. Given this discrepancy, the researchers aimed to investigate whether ghrelin levels, influenced by short-term fasting, could have a mood-enhancing effect in patients with major depressive disorder.
“We know that hunger has a profound effect on motivation and mood,” study authors said Nils B. Kramer, Professor at the University of Bonn and Group Leader at the University of Tübingen. “Although we often associate hunger with increased reward-seeking and negative mood (‘hunger’), fasting interventions have been shown to elicit antidepressant effects. As a result, we were particularly interested in the possible regulatory role of circulating levels of ghrelin, which is synthesized in the stomach when the stomach is empty. ”
The study involved 103 participants, including 52 patients with depression and 51 healthy control participants. Participants’ ages ranged from 20 to 50 years, and their BMI was within normal range. Those with severe mental disorders, eating disorders, or serious medical conditions were excluded.
Participants underwent two experimental sessions. During the first session, participants completed various questionnaires to assess demographics, dietary behaviors, physical activity, and symptoms of depression. Depression severity was measured using the Beck Depression Inventory and negative emotionality was assessed using the State-Trait Anxiety Inventory.
In the second session, participants fasted for 12 hours overnight and then visited the lab, where blood samples were taken to measure ghrelin levels. They also reported their feelings of hunger, satiety, thirst, fatigue, and mood using visual analog scales. Blood samples were analyzed for acyl and desacyl ghrelin levels.
Researchers have found that higher levels of acyl ghrelin, the active form of the hormone, are associated with improved mood. This effect was more pronounced in depressed patients compared to healthy control participants. Specifically, patients with higher levels of acyl ghrelin reported fewer negative emotions and more positive emotions.
“We showed that elevated ghrelin levels after an overnight fast were associated with improved mood in both healthy people and patients with depression,” Cromer told PsyPost. “These results suggest that the mood-enhancing effects of hunger may be related to its motivational effects. Ghrelin also promotes motivation by increasing dopamine release in the brain. “A better understanding of how signals from the gut improve mood could lead to more effective treatments for depression.”
The association between ghrelin and mood was stronger in depressed patients not taking antidepressants. This suggests that antidepressants may interfere with the mood-enhancing effects of ghrelin. Researchers also found that mood improvements were not limited to specific mood items and were generally associated with improvements in overall mood state.
“It was interesting that higher ghrelin levels were associated with improved mood, even though the participants did not experience increased hunger,” Cromer explained. “The most plausible explanation for this discrepancy is that most participants were very hungry, masking moderate differences in subjective hunger, while mood had no such ceiling effect. That’s it.”
This study highlights the importance of considering gut-derived signals in the treatment of depression. However, there are some caveats to consider. For example, this study focused on short-term fasting, but longer-term fasting or weight loss interventions may provide different insights. Furthermore, the researchers only measured endogenous levels of ghrelin and did not administer any experimental doses to determine the effects of ghrelin on mood.
“Fasting causes a series of hormonal changes,” Kromer points out. “Although our focus on ghrelin was based on theory, many other changes in circulating hormones may contribute to mood elevation. Therefore, it is important to conclusively demonstrate the mood-enhancing effects of ghrelin. To do so, we need an experimental design to administer ghrelin. These studies are ongoing.”
“Our long-term vision is to learn from the modulatory effects of body signals to improve the treatment of depression,” Cromer said. “We know, for example, that hunger can have a rapid and powerful impact on motivation and mood, but we can harness such body signals to determine greater clinically relevant effects over longer periods of treatment. We do not fully understand how the effect is achieved. In our opinion, targeting the gut-brain axis holds great promise in achieving meaningful improvements in therapeutic efficacy. It seems.”
the study, “Ghrelin is associated with elevated mood after an overnight fast in depressed patients” authors are Rauda Fahed, Corinna Schulz, Johannes Krauss, Sabine Ellinger, Martin Walter, and Nils B. Kremer.
