Clinical trial NCT06576440: Effects of Ghrelin Administration on Motivation
Official title: The Effects of Ghrelin Administration on Motivation and Resting Energy Expenditure
Study type: INTERVENTIONAL
Overall status: ENROLLING_BY_INVITATION
Phase: NA
Conditions: Major Depressive Disorder
Keywords: energy homeostasis
motivation
ghrelin
anhedonia
mood
Lead sponsor: University Hospital Tuebingen
Sponsor class: OTHER
First posted: 2024-08-28
Enrollment: 40
Sex: ALL
Minimum age (years): 20
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Everyday humans are confronted with a plethora of rewards competing for their attention. Nevertheless, to obtain a goal or reward, humans often need to invest effort. When humans are confronted with the challenge to integrate costs of action such as the effort of walking to one's favorite lunch place with its anticipated benefits (i.e., eating one's favorite meal), accumulating evidence suggest that humans might "go with the gut". Ghrelin is a stomach-derived hormone and the only known circulating peptide that stimulates appetite. At the same time, patients with major depressive disorder report deficits in motivated behavior which are oftentimes accompanied by changes in appetite and weight. Based on a wealth of accruing evidence from animal studies, the investigators suggest that the gut acts as an important arbitrator in effort allocation by signaling the energy level of the body. Within this physiological framework, ghrelin is thought to signal a short-term energy deficit to increase reward responsivity and willingness to work for reward as compensatory (allostatic) means. Here, the investigators propose to conduct a follow-up study (to NCT05318924) with subcutaneous administration of ghrelin vs. saline in patients with major depressive disorder and healthy control participants. During each visit, participants will receive a subcutaneous administration of either ghrelin or saline and perform an effort allocation task where they have to exert physical effort to obtain food and monetary rewards. The investigators hypothesize that ghrelin will increase the motivation to exert effort for rewards. The goal of this follow-up study is to test that the motivational effects of ghrelin are similar in patients with depression and healthy control participants. Furthermore, participants resting energy expenditure will be estimated before and after the administration. In line with a role of ghrelin as an energy deficit signal, the investigators expect ghrelin to decrease energy expenditure. During each visit, participants will answer questions about their current mood and physiological state. The investigators hypothesize that ghrelin increases mood state and hunger while decreasing satiety.


Eligibility criteria: Inclusion Criteria:

\* Must have participated in the behavioral study arm of NCT05120336

Exclusion Criteria:

* participation in the neuroimaging part of NCT05120336
* breastfeeding
* pregnancy

Primary outcomes:
measure: Ghrelin-induced changes in motivation
timeFrame: 15-50 minutes after subcutaneous administration (ghrelin vs. saline)
measure: Ghrelin-induced changes in Resting Energy Expenditure
timeFrame: Pre injection versus 50-65 minutes after injection (compared to saline)
measure: Ghrelin-induced changes in mood
timeFrame: Pre injection timepoints (mean over 40 minutes and 5 minutes before) versus post injection timepoints (mean over 15, 50 and 65 minutes after injection) (compared to saline)
measure: Ghrelin-induced changes in hunger and satiety from baseline
timeFrame: Pre injection timepoints (mean over 40 minutes and 5 minutes before) versus post injection timepoints (mean over 15, 50 and 65 minutes after injection) (compared to saline)
Secondary outcomes:
Other outcomes:
Locations:
city: Tübingen
country: Germany
facility: Department of Psychiatry & Psychotherapy, University of Tübingen
state: BW
Study officials:
affiliation: University of Tübingen, Faculty of Medicine, Department of Psychiatry & Psychotherapy
name: Nils B Kroemer, PhD
role: PRINCIPAL_INVESTIGATOR
References: