← Back to Clinical Trials
Recruiting NCT03911726

NCT03911726 Do Antipsychotic Agents Induce Supersensitivity in Humans: A Combined PET/MRI Study in Patients With Schizophrenia

◆ AI Clinical Summary
Plain-language summary for patients
Clinical Trial Summary
NCT ID NCT03911726
Status Recruiting
Phase —
Sponsor Central Institute of Mental Health, Mannheim
Condition Schizophrenia
Study Type INTERVENTIONAL
Enrollment 140 participants
Start Date 2020-08-01
Primary Completion 2028-06

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age 65 Years
Study Type INTERVENTIONAL
Interventions
Single PET/MR-measurement

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

This trial targets 140 participants in total. It began in 2020-08-01 with a primary completion date of 2028-06.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The aim of the present study is to detect changes in the dopamine system in the brain of patients with schizophrenia, especially when pretreated with antipsychotic medication. Here, the investigators want to find out whether the treatment with these drugs can cause permanent changes in docking points (receptors) of dopamine in the brain. It will be examined whether number and response of dopamine receptors is altered, which are associated with the onset of psychotic symptoms. For this purpose, a single PET/MR measurement will be performed in all participants. In total 140 volunteers, consisting of 30 healthy volunteers, 20 first-episode, drug-naive patients with schizophrenia and 90 pretreated patients with schizophrenia will be included over a time period of three years. In addition, the influence of nicotine consumption on dopamine receptors will be invesitgated by comparing data from smoking and non-smoking patients. In clinical practice, an elevation of dopamine action caused by alterations in receptors in the brain is of most importance. This may be the reason why the treatment with antipsychotic agents does not work in some patients. In addition, a permanent elevation of dopamine action is associated with permanent brain alterations by these drugs. The result can contribute to work out valuable indications, whether it makes sense to continue a long term therapy with antipsychotic drugs in a patient. But also the in-depth understanding of the impact of nicotine on the course of therapy can help to open up possibilities for improved drug treatment.

Eligibility Criteria

Inclusion Criteria for healthy subjects: * Age: 18-65 * The subject is capable to understand scope and individual consequences of the clinical study. * An informed consent is signed and personally dated by the subject. • No psychiatric disorder (DSM-5) currently, or in the medical history (ensured by a standardized psychiatric interview Mini International Neuropsychiatric Interview (M.I.N.I.)). Inclusion Criteria for patients: * Age: 18-65 * The criteria for schizophrenia after DSM-5 are met. * The subject is capable to understand scope and individual consequences of the clinical study. * For first-episode patients, no application of antipsychotic drugs in history. Other psychoactive substances (in particular antidepressants) are allowed if last application is at least three months ago and total Duration did not exceed three months. Benzodiazepines are allowed. * For medically pretreated patients: at least one year pharmacotherapy with one of the following three substances: aripiprazole or quetiapine or risperidone. A medication break of - depending on the plasma level - two days (quetiapine) up to two weeks (aripiprazole) should be clinically defensible. * An informed consent is signed and personally dated by the patient. For patients with legal support in addition: signature of the legal supervisor. Exclusion criteria for patients and subjects: * Hypersensitivity against apomorphine or a chemically similar substance or one of the components of the applied medication. * Participation in other clinical trials during or within six months prior to this clinical study. * Medical or psychological conditions which may endanger a proper performance of the clinical trial. * Physical disorders which interfere according to type and severity with the planned examinations, which could influence the parameter to be investigated or could compromise the subject during the examination procedure. * Inability to comply with the study protocol. * Limited or completely repealed legal capacity. * For female participants: positive pregnancy test on the day of the study inclusion or on the day of the PET/MR-measurement. * Acute suicidality or endangerment * Poor general condition. * Participation in a study using ionising Radiation within the last five years. * Alcohol abuse, alcohol dependence or addiction disease / abuse of dependence-inducing substances (excluding nicotine) in the history, additional exclusion criterion for healthy subjects: regular medication intake; within the last two weeks before PET/MR-measurement no drugs at all must be taken. Additional exclusion criterion for patients: other than the approved axis I diagnosis according to DSM-5. An axis II diagnosis is not a criterion for exclusion

Contact & Investigator

Central Contact

Gerhard Gründer, Prof. Dr.

✉ gerhard.gruender@zi-mannheim.de

📞 +49621 1703-1900

Principal Investigator

Gerhard Gründer, Prof. Dr.

PRINCIPAL INVESTIGATOR

Central Institute of Mental Health, Mannheim

Frequently Asked Questions

Who can join the NCT03911726 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, up to 65 Years, studying Schizophrenia. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

Is NCT03911726 currently recruiting?

Yes, NCT03911726 is actively recruiting participants. Contact the research team at gerhard.gruender@zi-mannheim.de for enrollment information.

Where is the NCT03911726 trial being conducted?

This trial is being conducted at Mannheim, Germany.

Who is sponsoring the NCT03911726 clinical trial?

NCT03911726 is sponsored by Central Institute of Mental Health, Mannheim. The principal investigator is Gerhard Gründer, Prof. Dr. at Central Institute of Mental Health, Mannheim. The trial plans to enroll 140 participants.

Related Trials

Related Intelligence Guides

In-depth guides covering this condition's trials, eligibility, and what to expect.

ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: November 2026  ·  Data Methodology