Using a PET tracer to study serotonin receptors in neurodegenerative diseases

Characterization of the Serotonin 2A Receptor Selective PET Tracer [18F]MH.MZ in Patients With Neurodegenerative Diseases

Phase 4 Interventional Vanderbilt University Medical Center · NCT05357612

This study is testing how a new imaging method can help us understand serotonin receptors in people with neurodegenerative diseases like Parkinson's and see if a medication can improve their psychosis symptoms.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment75 (estimated)
Ages50 Years to 85 Years
SexAll
SponsorVanderbilt University Medical Center Academic / other
Locations1 site (Nashville, Tennessee)
Trial IDNCT05357612 on ClinicalTrials.gov

What this trial studies

This study aims to investigate the differences in serotonin 2A receptor occupancy between patients with neurodegenerative diseases, such as Parkinson's disease, and healthy controls. It will utilize the PET radioligand (R)-[18F]MH.MZ to measure receptor density and assess the impact of the drug pimavanserin on psychosis symptoms. Patients will undergo PET and MRI scans at baseline and after six weeks of treatment to evaluate changes in receptor occupancy and functional connectivity related to psychotic symptoms. The study seeks to establish a correlation between receptor density, drug effects, and neuroimaging changes.

Who should consider this trial

Good fit: Ideal candidates include patients with a clinical diagnosis of Parkinson's disease or related neurodegenerative conditions who experience psychosis symptoms.

Not a fit: Patients with psychosis due to metabolic, toxic, or primary psychiatric diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved treatment strategies for psychosis in patients with neurodegenerative diseases.

How similar studies have performed: Other studies have shown promise in using PET imaging to assess receptor occupancy in neurodegenerative diseases, but this specific approach is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patient arm - clinical diagnosis of Parkinson disease, diffuse Lewy body disease, multiple systems atrophy, Huntington's Disease, Frontotemporal Dementia, and other variants
* Healthy arm - age and gender matched to patient arm
* Psychosis (presence of hallucinations or delusions) starting after the diagnosis of Parkinson's disease, occurring at least weekly for 4 weeks, severe enough to warrant treatment.
* Study partner available for study visits

Exclusion Criteria:

* Prior stroke or other uncontrolled serious neurological or medical illness
* Contra-indication or inability to tolerate MRI scan
* Use of serotonergic medications in the last 6 weeks
* Incapable of providing independent consent.
* Pregnant or breastfeeding women
* psychosis due to a metabolic, toxic, or primary psychiatric disease
* Deemed unable to complete neurocognitive testing
* For PD Participants: current or prior use of pimavanserin
* Use of antipsychotics in the last 2 weeks

Where this trial is running

Nashville, Tennessee

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Neurodegenerative DiseasesParkinson DiseaseParkinson Disease Psychosis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.