Exceptional Experiences (EE), Salience & Dopaminergic Neurotransmission
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.
Studieoversigt
Status
Status
Betingelser
Betingelser
Intervention / Behandling
Intervention / Behandling
Undersøgelsestype
Undersøgelsestype
Tilmelding (Faktiske)
Tilmelding
Fase
Fase
- Tidlig fase 1
Kontakter og lokationer
Studiesteder
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Zürich, Schweiz, 8006 Zürich
- Collegium Helveticum, ETH & Universität Zürich
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Deltagelseskriterier
Berettigelseskriterier
Berettigelseskriterier
Aldre berettiget til at studere
Tager imod sunde frivillige
Køn, der er berettiget til at studere
Beskrivelse
Inclusion Criteria:
- Healthy,
- Between 20 and 40 years of age,
- With exceptional experiences or skeptics,
- Caucasian origin,
- Normal visual and acoustic accuracy.
Exclusion Criteria:
- 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,
- left- or mixed-handedness,
- General MRI exclusion criteria,
- General Dopamine-Challenge exclusion criteria,
- Hormonal or herbal therapy,
- Smoker.
Studieplan
Hvordan er undersøgelsen tilrettelagt?
Design detaljer
- Primært formål: Grundvidenskab
- Tildeling: Randomiseret
- Interventionel model: Crossover opgave
- Maskning: Tredobbelt
Antal våben
Våben og indgreb
Deltagergruppe / ArmDeltagergruppe / Arm |
Intervention / BehandlingIntervention / Behandling |
|---|---|
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Aktiv komparator: Madopar Arm
A single dose of a cachet filled with 200 mg levodopa/50 mg benserazide
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Andre navne:
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Placebo komparator: Placebo Arm
A single dose of a cachet filled with Dextrose
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Andre navne:
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Hvad måler undersøgelsen?
Primære resultatmål
Primære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
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intrinsic functional connectivity
Tidsramme: 2 hours
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Dopamine dependent intrinsic functional connectivity as measured by resting-state functional magnetic resonance imaging
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2 hours
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Sekundære resultatmål
Sekundære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
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Schizotypy
Tidsramme: 15 min
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Schizotypy scores assessed by the Schizotypal Personality Questionnaire (SPQ):
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15 min
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Samarbejdspartnere og efterforskere
Sponsor
Sponsor
Samarbejdspartnere
Samarbejdspartnere
Datoer for undersøgelser
Studer store datoer
Studiestart (Faktiske)
Studiestart
Primær færdiggørelse (Faktiske)
Primær færdiggørelse
Studieafslutning (Faktiske)
Studieafslutning
Datoer for studieregistrering
Først indsendt
Først indsendt
Først indsendt, der opfyldte QC-kriterier
Først indsendt, der opfyldte QC-kriterier
Først opslået (Faktiske)
Først opslået
Opdateringer af undersøgelsesjournaler
Sidste opdatering sendt (Faktiske)
Sidste opdatering sendt
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
Sidst verificeret
Sidst verificeret
Mere information
Begreber relateret til denne undersøgelse
Yderligere relevante MeSH-vilkår
Andre undersøgelses-id-numre
Andre undersøgelses-id-numre
- DA_EE_Salience
Plan for individuelle deltagerdata (IPD)
Planlægger du at dele individuelle deltagerdata (IPD)?
Lægemiddel- og udstyrsoplysninger, undersøgelsesdokumenter
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