protocolSection identificationModule nctId: NCT06365515, orgStudyIdInfo id: TUE010_IRTG_P5, briefTitle: Dopamine, Reward Learning and Sex Hormones, statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-04, primaryCompletionDateStruct date: 2025-12, completionDateStruct date: 2025-12, studyFirstPostDateStruct date: 2024-04-15, lastUpdatePostDateStruct date: 2024-04-15, sponsorCollaboratorsModule leadSponsor name: University Hospital Tuebingen, class: OTHER, collaborators name: German Research Foundation, collaborators name: Uppsala University, descriptionModule briefSummary: Hormonal transition periods during the menstrual cycle may predispose women to mental disorders. Hormonal fluctuations provide specific neuroendocrine conditions that modulate brain structure and function and these actions affect cognitive and emotional behaviors and affect energy and mood homeostasis. It is thought that these changes are driven by altered dopamine transmission. Here, we aim to examine (1) how sex hormones and dopamine are linked and also (2) how hormonal changes affect motivation, mood, and energy homeostasis.To this end, dopamine intervention will be tested on effort-based decision-making and motivational circuits in three hormonal stages (i.e., women in early-follicular phase (EF), women in mid-luteal phase (ML), and men). Additionally, we are testing the effects of hormonal status on metabolic indices and its effects on mood fluctuations in a period of a month.The investigator hypothesizes that women in EF cycle phase (1) have naturally less dopamine and show less effort, and (2) they show greater improvement in effort-based decision-making after Levodopa administration. We have exploratory outcomes about (3) sex differences in reward-learning with and without Levodopa administration and explore if these differences correlate with elevated female sex hormone levels. Moreover, it is hypothesized that (4) hormonal fluctuations affect energy homeostasis, thus women in their EF cycle phase have higher energy expenditure and (5) they report more negative mood than in their mid-luteal (ML) cycle phase., conditionsModule conditions: Hormonal Changes, conditions: Menstrual Cycle, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: RANDOMIZED, interventionModel: CROSSOVER, interventionModelDescription: The investigators will assess the effects of Levodopa administration on reward-learning using a double-blind randomized cross-over design. In a within-subject design, participants will get both conditions (Levodopa/placebo) at different time points (a few days apart). After drug/placebo administration we will assess cerebral blood flow and functional connectivity at rest (via functional MR imaging) during effort-based decision making task., primaryPurpose: BASIC_SCIENCE, maskingInfo masking: TRIPLE, maskingDescription: Neither participants nor investigators will know at which time point the participant will receive Levodopa and placebo tablets. The tablets will be prepared by independent members of the university hospital., whoMasked: PARTICIPANT, whoMasked: INVESTIGATOR, whoMasked: OUTCOMES_ASSESSOR, enrollmentInfo count: 90, type: ESTIMATED, armsInterventionsModule interventions name: Levodopa administration, interventions name: Placebo administration, outcomesModule primaryOutcomes measure: Motivation to work for rewards: force of pressing grip force device (GFD) to gain food and monetary rewards circuitry during effort-based decision-making, primaryOutcomes measure: Reward-related brain responses in the reward network during effort-based decision-making, primaryOutcomes measure: Reward anticipation on a neural level, primaryOutcomes measure: Execution of effort on a neural level, secondaryOutcomes measure: Resting-state functional connectivity, secondaryOutcomes measure: Changes in reinforcement learning, secondaryOutcomes measure: Menstrual cycle induced changes in mood and food cravings, secondaryOutcomes measure: Changes in resting energy expenditure, secondaryOutcomes measure: Changes in metabolic hormone levels during the menstrual cycle, eligibilityModule sex: ALL, minimumAge: 20 Years, maximumAge: 35 Years, stdAges: ADULT, contactsLocationsModule locations facility: Department of Psychiatry & Psychotherapy, University of Tübingen, city: Tübingen, state: BW, zip: 72076, country: Germany, contacts name: Andrea Heberle, role: CONTACT, email: Andrea.Heberle@med.uni-tuebingen.de, geoPoint lat: 48.52266, lon: 9.05222, hasResults: False