HealthyEarly Phase 1NCT03333369
Exceptional Experiences (EE), Salience & Dopaminergic Neurotransmission
A Early Phase 1 study testing 200 mg levodopa/50 mg benserazide and Dextrose in people with Healthy and Schizotypal Personality, run by University of Zurich at 1 site in Switzerland.
Trial summary
The dopamine hypothesis of schizophrenia implies that alterations in the dopamine system cause functional abnormalities in the brain that may converge to aberrant salience attribution and eventually lead to psychosis. Read more about this study
- Who is it for?
- Ages 20 to 60 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy, Schizotypal Personality
- What is being tested?
- 200 mg levodopa/50 mg benserazide and Dextrose
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 65 participants
- Where
- 1 siteSwitzerland
- Study dates
- 15 May 2014to 13 Aug 2015
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 60 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy,
- Between 20 and 40 years of age,
- With exceptional experiences or skeptics,
- Caucasian origin,
- Normal visual and acoustic accuracy.
Who cannot join
- Persons with a personal or first-degree family history of neurological and psychiatric disease, including impaired cognitive abilities,
- Pregnant or breastfeeding women,
- Chronic or acute pain,
- Acute or chronic somatic disease,
- Women (i.e. only men included),
- Men over 40 years of age or below 20,
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- left- or mixed-handedness,
- General MRI exclusion criteria,
- General Dopamine-Challenge exclusion criteria,
- Hormonal or herbal therapy,
- Smoker.
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Collegium Helveticum, ETH & Universität Zürich
Zurich, 8006 Zürich
About this study
Official title: L-Dopa Modulated Striatal Functional Connectivity in Schizotypal Adults: a Randomized Double-blind Placebo-controlled Study
The dopamine hypothesis of schizophrenia implies that alterations in the dopamine system cause functional abnormalities in the brain that may converge to aberrant salience attribution and eventually lead to psychosis. Indeed, widespread brain disconnectivity across the psychotic spectrum has been revealed by resting-state functional magnetic resonance imaging (rs-fMRI). However, the dopaminergic involvement in intrinsic functional connectivity (iFC) and its putative relationship to the development of psychotic spectrum disorders remains partly unclear - in particular at the low-end of the psychosis continuum. Therefore, the investigators examined dopamine-induced changes in striatal iFC and their modulation by psychometrically assessed schizotypy. The randomized, double-blind placebo-controlled study design included 54 healthy, right-handed male participants. Each participant was assessed with the Schizotypal Personality Questionnaire (SPQ) and underwent 10 min of rs-fMRI scanning. Participants then received either a placebo or 200 mg of L-DOPA, a dopamine precursor. The investigators analyzed iFC of six striatal seeds that are known to evoke modulation of dopamine-related networks.
The investigators hypothesized that, within the L-DOPA treatment group, the striatal iFC would be disrupted due to increased availability of dopamine. The investigators further hypothesized that individuals with high schizotypal scores would show a disruption of striatal connectivity, as has been reported with schizophrenia. In addition, the investigators hypothesized that the L-DOPA-dependent change in striatal iFC would interact with the severity of positive symptoms, as has been found in previous studies in non-clinical psychosis. The investigators anticipated this symptom-dependent change, especially in the ventral striatal regions, because these are thought to modulate cortico-striatal loops associated with cognition and emotion.
- Conditions
- Healthy, Schizotypal Personality
- Being tested
- 200 mg levodopa/50 mg benserazide, Dextrose
- Keywords
- resting-state functional MRI, Dopamine, functional connectivity
- Medical subject headings
- Schizotypal Personality Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
200 mg levodopa/50 mg benserazideDrug
Also called Madopar DR
DextroseDrug
Also called Placebo
| Study group | Role | What they receive |
|---|---|---|
| Madopar Arm | Active comparator | A single dose of a cachet filled with 200 mg levodopa/50 mg benserazide Receives: Drug: 200 mg levodopa/50 mg benserazide |
| Placebo Arm | Placebo comparator | A single dose of a cachet filled with Dextrose Receives: Drug: Dextrose |
What is being measured
The primary outcome is the main question the study is designed to answer.
intrinsic functional connectivity
Dopamine dependent intrinsic functional connectivity as measured by resting-state functional magnetic resonance imaging
Measured: 2 hours
Secondary outcomes (1)
Schizotypy
Schizotypy scores assessed by the Schizotypal Personality Questionnaire (SPQ):
- n of items 74 (min. score = 0 ; max. score = 74): higher score implies higher level of schizotypy
- Subscales:
- Cognitive Perceptual (min. score = 0 ; max. score = 33)
- Interpersonal (min. score = 0 ; max. score = 25)
- Disorganized (min. score = 0 ; max. score = 16)
Measured: 15 min
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2017
- Study start15 May 2014
- Primary completion13 Aug 2015
- Study completion13 Aug 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of ZurichThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Each subject in the group will participate in two test sessions, separated by at least one week. All sessions will start at 15:30. In a double-blind within-design procedure, participants will be randomly assigned to receive either a cachet of a dual-release formulation of 200 mg levodopa/50 mg benserazide (a peripheral L-dihhydroxyphenylalanine-decarboxylase inhibitor) or a placebo in the first session. In the second session they will receive the other intervention.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 65 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- Swiss Federal Institute of Technology
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03333369
- Sponsor's protocol ID
- DA_EE_Salience
- Status last verified
- Nov 2017
- First submitted
- 30 Oct 2017
- Last updated
- 6 Nov 2017
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- L-Dopa Modulated Striatal Functional Connectivity in Schizotypal Adults: a Randomized Double-blind Placebo-controlled Study
- ClinicalTrials.gov ID
- NCT03333369
- Acronym / sponsor ID
- DA_EE_Salience
- Conditions
- Healthy, Schizotypal Personality
- Keywords
- resting-state functional MRI, Dopamine, functional connectivity
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 65 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Collaborators
- Swiss Federal Institute of Technology
- Study start
- 15 May 2014 (actual)
- Primary completion
- 13 Aug 2015 (actual)
- Study completion
- 13 Aug 2015 (actual)
- First posted
- 6 Nov 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The dopamine hypothesis of schizophrenia implies that alterations in the dopamine system cause functional abnormalities in the brain that may converge to aberrant salience attribution and eventually lead to psychosis. Indeed, widespread brain disconnectivity across the psychotic spectrum has been revealed by resting-state functional magnetic resonance imaging (rs-fMRI). However, the dopaminergic involvement in intrinsic functional connectivity (iFC) and its putative relationship to the development of psychotic spectrum disorders remains partly unclear - in particular at the low-end of the psychosis continuum. Therefore, the investigators examined dopamine-induced changes in striatal iFC and their modulation by psychometrically assessed schizotypy. The randomized, double-blind placebo-controlled study design included 54 healthy, right-handed male participants. Each participant was assessed with the Schizotypal Personality Questionnaire (SPQ) and underwent 10 min of rs-fMRI scanning. Participants then received either a placebo or 200 mg of L-DOPA, a dopamine precursor. The investigators analyzed iFC of six striatal seeds that are known to evoke modulation of dopamine-related networks.
The investigators hypothesized that, within the L-DOPA treatment group, the striatal iFC would be disrupted due to increased availability of dopamine. The investigators further hypothesized that individuals with high schizotypal scores would show a disruption of striatal connectivity, as has been reported with schizophrenia. In addition, the investigators hypothesized that the L-DOPA-dependent change in striatal iFC would interact with the severity of positive symptoms, as has been found in previous studies in non-clinical psychosis. The investigators anticipated this symptom-dependent change, especially in the ventral striatal regions, because these are thought to modulate cortico-striatal loops associated with cognition and emotion.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
- Model description
- Each subject in the group will participate in two test sessions, separated by at least one week. All sessions will start at 15:30. In a double-blind within-design procedure, participants will be randomly assigned to receive either a cachet of a dual-release formulation of 200 mg levodopa/50 mg benserazide (a peripheral L-dihhydroxyphenylalanine-decarboxylase inhibitor) or a placebo in the first session. In the second session they will receive the other intervention.
| Arm | Type | Receives |
|---|---|---|
| Madopar Arm | Active comparator | Drug: 200 mg levodopa/50 mg benserazideA single dose of a cachet filled with 200 mg levodopa/50 mg benserazide |
| Placebo Arm | Placebo comparator | Drug: DextroseA single dose of a cachet filled with Dextrose |
Who may qualify
- Ages
- 20 to 60 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Healthy,
- Between 20 and 40 years of age,
- With exceptional experiences or skeptics,
- Caucasian origin,
- Normal visual and acoustic accuracy.
Key exclusion criteria (11 listed)
- Persons with a personal or first-degree family history of neurological and psychiatric disease, including impaired cognitive abilities,
- Pregnant or breastfeeding women,
- Chronic or acute pain,
- Acute or chronic somatic disease,
- Women (i.e. only men included),
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 200 mg levodopa/50 mg benserazideAlso: Madopar DR | Drug | Madopar Arm |
| DextroseAlso: Placebo | Drug | Placebo Arm |
Primary outcome
intrinsic functional connectivity
Time frame: 2 hours
Dopamine dependent intrinsic functional connectivity as measured by resting-state functional magnetic resonance imaging
1 secondary outcome
Schizotypy
Time frame: 15 min
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2017.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing 200 mg levodopa/50 mg benserazide and Dextrose in people with Healthy and Schizotypal Personality, run by University of Zurich at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Nov 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
intrinsic functional connectivity (time frame: 2 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2017.