REALITY MONITORING (MORDOR)

Hôpital le Vinatier

Status

Enrolling

Conditions

Neurosciences

Treatments

Other: PLACEBO

Other: antagoniste D2

Other: Précurseur de la dopamine

Study type

Interventional

Funder types

Other

Identifiers

NCT05711082

2022-A01345-38

Details and patient eligibility

About

Reality-monitoring characterizes the ability to determine whether information was perceived in the environment or only imagined . Impaired reality-monitoring abilities have been associated with hallucinations in patients with schizophrenia and patients with Parkinson's disease.

The investigators hypothesize a link between dopaminergic (DA) transmission and reality-monitoring.

Full description

This hypothesis is based on several studies in the literature: 1) DA transmission anomalies are observed in both schizophrenia and Parkinson's disease; 2) DA agonists may induce hallucination; 3) DA antagonists reduce hallucinations and improve reality-monitoring abilities in patients with schizophrenia. In addition, also suggesting a link between mesocorticolimbic connectivity, subcortical DA transmission and reality-monitoring, The investigators have shown that fronto-temporal transcranial Direct Current Stimulation (tDCS) leads:

on the one hand, to modulate reality-monitoring performance in healthy volunteers and patients;
on the other hand, to induce subcortical DA release. However, to date, no study has yet explored the direct link between DA transmission and reality-monitoring.

Enrollment

39 estimated patients

Sex

All

Ages

18 to 45 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Healthy volunteers who have given their written informed consent
Men and women from 18 to 45 years old
Normal or corrected vision
Being fluent in French or French for native language
Being affiliated with health insurance

Exclusion criteria

Healthy volunteers who have given their written informed consent
Men and women from 18 to 45 years old
Normal or corrected vision
Being fluent in French or French for native language
Being affiliated with health insurance
Inadmissibility of the subject's consent or refusal
Working-memory deficit (as controlled with MMSE score< 23)
Any past or current psychiatric or somatic condition(as controlled with the Mini International Neuropsychiatric Interview, MINI)
Any past or current neurological condition
History of cranio-cerebral trauma, arterial hypotension or hypertension, cardiological or serious medical condition
Abnormal potassium dosage (below 3.1 mmol/L or above 4.9 mmol/L)
Anormal ECG
History of schizophrenia or bipolar disorder in first-degree relatives
Alcohol-drinking and caffeine intake at least during 24 hours before each session
Drug therapy excepting contraceptives
Cardiologic or severe medical conditio
Pregnancy(checked with a pregnancy autotest), lactation, or insufficient contraceptive measure (precautionary measure)
Consumption of recreational drugs during the last 6 months
Known sensitivity to any of the study medication and their excipients
Lactose intolerance
Porphyria
Hepatic insufficiency

Trial design

Primary purpose

Basic Science

Allocation

Randomized

Interventional model

Crossover Assignment

Masking

Single Blind

39 participants in 3 patient groups, including a placebo group

Dopamine precursor

Active Comparator group

Description:

In the first condition, volunteers will receive a dopamine (DA) precursor (L-dopa, 100mg). L-dopa will be combined with a dose of an Aromatic amino acid decarboxylase inhibitor (Benserazide) 25mg to multiplicate its bioavailability and with a dose of domperidone 10mg (peripheral antagonist of DA) to minimize the risk of side effects.

Treatment:

Other: Précurseur de la dopamine

D2 antagonist

Active Comparator group

Description:

In the second condition, volunteers will receive a D2 antagonist (Sulpiride, 800mg)

Treatment:

Other: antagoniste D2

PLACEBO

Placebo Comparator group

Description:

In the third condition, volunteers will receive a placebo (lactose)