An interventional study of L-dopa/Carbidopa and Placebo in Depressive Disorder, Major, sponsored by Charite University, Berlin, Germany. Recruiting at 1 site in Germany. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-18.
Sponsored by Charite University, Berlin, Germany · Not applicable, Interventional, and Basic science
A large body of evidence on depression heterogeneity point to an "immunometabolic" subtype characterized by the clustering of immunometabolic dysregulations with atypical behavioral symptoms related to energy homeostasis. Motivational and motor impairments reflected by symptoms of anhedonia and psychomotor retardation in major depression are closely related to alterations in energy homeostasis, are associated with increased inflammation, and may be a direct consequence of the impact of inflammatory cytokines on the dopamine system in the brain. In the proposed project, the investigators will examine the effect of dopamine stimulation on motivation and motor function in patients with major depression and healthy controls and the role of inflammation using a double-blind, randomized, placebo-controlled, cross-over design. If successful, this study would provide crucial evidence that pharmacologic strategies that increase dopamine may effectively treat inflammation-related symptoms of anhedonia and psychomotor retardation in major depression.
3,041 studies on the registry are indexed under Depressive Disorder, Major; 588 are open to participants now.
This study's planned enrollment of 165 is above the median of 79 across 2,530 interventional studies indexed under Depressive Disorder, Major.
Browse Depressive Disorder, Major studies →Charite University, Berlin, Germany is the lead sponsor of 857 studies on the registry; 129 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
For patients with major depressive disorder:
For healthy participants:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive first L-dopa/Carbidopa (100/25 mg), and then placebo.
Drug: L-dopa/Carbidopa · Drug: Placebo
Participants will receive first placebo, and then L-dopa/Carbidopa (100/25 mg).
Drug: L-dopa/Carbidopa · Drug: Placebo
The change in response bias (logb) after L-dopa/Carbidopa compared to placebo in the Probabilistic Reward Task (PRT).
The PRT, which uses a signal detection paradigm, will be used to measure response bias, the propensity to select the more rewarded response ("rich").
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
The change in mean gait speed [m/s] after L-dopa/Carbidopa compared to placebo in the dual task.
The dual task mean gait speed will be measured with six wearable inertial measurement units. In this dual task, participants walk at their usual speed while naming as many animals as possible.
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
The change in choice of the hard task after L-dopa/Carbidopa compared to placebo in the Effort Expenditure for Rewards Task (EEfRT).
The EEfRT, a widely used, multi-trial task in which participants are given an opportunity on each trial to choose between two different task difficulty levels in order to obtain monetary rewards, will be used as an objective measure of reward motivation. The EEfRT is reported as the percent of high effort (hard) trials selected. A higher percentage reflects higher motivation for effort expenditure.
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
The change in movement time [ms] after L-dopa/Carbidopa compared to placebo in the Reaction Time Task (RTI).
The RTI from the Cambridge Neuropsychological Test Automated Battery (CANTAB) will be used to assess movement time, which is the time taken to touch the stimulus on the computer screen after the press pad had been released.
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
The change in risk propensity after L-dopa/Carbidopa compared to placebo in the Risky Decision-Making Task.
In the Risky Decision-Making Task, participants have to make choices between a risky option and a safe alternative. Risk Propensity, the proportion of risk-taking trials, will be a secondary outcome.
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
Response bias (logb) in the PRT
Time frame: After administration of placebo on Day 2 or Day 3.
Mean gait speed [m/s] in the dual task
Time frame: After administration of placebo on Day 2 or Day 3.
Choice of the hard task in the EEfRT
Time frame: After administration of placebo on Day 2 or Day 3.
Movement time [ms] in the RTI
Time frame: After administration of placebo on Day 2 or Day 3.
The change in speed and accuracy after L-dopa/Carbidopa compared to placebo in the Rapid Visual Information Processing Task (RVP).
The RVP from the Cambridge Neuropsychological Test Automated Battery (CANTAB) will be used to assess performance speed (mean latency for correct responses) and accuracy (target sensitivity score).
Time frame: All participants will be tested on two separate experimental sessions separated by an interval of 48 hours, after L-dopa/Carbidopa or placebo.
Risk propensity in the Risky Decision-Making Task
Time frame: At baseline on Day 1.
Plan to share: Undecided
No publications or documents are linked to this record.
Started Jul 2023 (actual). Primary completion is estimated for Jul 2026, 36 months after the start.
Of 647 non-industry interventional studies with no phase under Depressive Disorder, Major, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 55. This study's planned 36 months is close to that.
Counting every sponsor, half of 687 studies reached it within 33 months; a quarter within 17 and three quarters within 55.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drugs tested here: Levodopa · Carbidopa
Charite University, Berlin, Germany →