NCT06278246

Investigating the Muscarinic System in Schizophrenia Using Positron Emission Tomography

The Muscarinic Hypothesis of Schizophrenia: an [11C]MK-6884 PET Study Study Protocol

• Status: Active Not Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 58 (estimated)
• Sponsor: Centre for Addiction and Mental Health · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Within the schizophrenia population, there are individuals that respond to first-line antipsychotic treatments while others do not. The availability of muscarinic M4 subtype receptors (M4R) may play a role as to whether a person with schizophrenia is responsive to first-line antipsychotics or not. The goal of this observational study is to compare the availability of M4R in antipsychotic-free patients with schizophrenia and matched healthy controls. In addition, M4R availability in schizophrenia patients will be examined in relation to response to first line antipsychotics and clinical and cognitive measures. This study may help better understand antipsychotic resistance in schizophrenia and lead to the development of new treatment options, particularly for cognitive deficits and negative symptoms.

Detailed description

This study is composed of two participant groups. 1) Antipsychotic-free patients with schizophrenia and 2) healthy matched controls. The healthy controls will be matched as closely as possible for age, sex, cannabis, and nicotine consumption to the patient group. All participants will undergo a positron emission tomography (PET) scan to measure the M4R binding with \[11C\]MK-6884 and examine its relationship with clinical and cognitive measures. Participants who meet the inclusion and exclusion criteria at screening visit (visit 1) will be enrolled into the study. All participants will undergo a PET scan with the novel tracer \[11C\]MK-6884 to examine its binding with M4R. The third visit will consist of a MRI scan and cognitive assessments. Participants with schizophrenia will have visit four, which occurs 6 weeks after the first antipsychotic trial, initiated by their treating physician. If the treating physician starts a second antipsychotic trial, then a visit five occurs 6 weeks after the second trial. Both visits four and five involve clinical and cognitive assessments.

Conditions

• Schizophrenia
• Schizophreniform Disorders

Interventions

Type	Name	Description
RADIATION	PET Scan	PET scan using the novel \[11C\]MK-6884 tracer to measure M4R during the antipsychotic-free state

Timeline

• Start date: 2024-03-11
• Primary completion: 2026-03-01
• Completion: 2026-03-01
• First posted: 2024-02-26
• Last updated: 2025-03-28

Locations

1 site across 1 country: Canada