Investigating the Muscarinic System in Schizophrenia Using Positron Emission Tomography

Prior treatment

• Unstable medical illness or any concomitant major medical or neurological illness, including a history of seizures and traumatic head injury resulting in a loss of consciousness \> 30 minutes that required medical attention.
• DSM-V substance use disorder (except caffeine and nicotine) within one month prior to study entry.
• Positive urine drug screen for drugs of abuse at the screening visit (excluding cannabis and/or benzodiazepines).
• Reporting the chronic use of medication with muscarinic mechanism of action.
• If participation in the study would expose participants to more than the annual radiation dose limit (20 mSv) for human subjects participating in research studies, or if the potential participant already underwent a number of PET scans that, including the PET scans under this protocol, will bring the total to more than 8 PET scans /lifetime. For example, participants known to have already been exposed to radiation through X-rays, CT-scans, or other nuclear medicine procedures during the last year may have already surpassed, or will surpass via study participation, the annual radiation dose limit and thus be excluded.
• Previous clozapine treatment.

Other illness

• DSM-V diagnosis of schizoaffective disorder or psychosis not otherwise specified.
• Pacemakers, metallic cardiac valves, magnetic material such as surgical clips, implanted electronic infusion pumps or any other conditions that would preclude the MRI scan
• Blood or coagulation disorders, or taking anticoagulant medication (not antiplatelet).
  • Patients with Schizophrenia will also be excluded if they meet ANY of the criteria listed below:

Age

• Pregnancy (Note: Females up to age 65 must have negative urine pregnancy test at screening), or breastfeeding.

Other

• Participants will be excluded if they meet ANY of the criteria listed below:
• Acute suicidal and/or homicidal ideation.
• Clinically significant claustrophobia
• Size of head, neck, and body being unable to fit MRI or PET scanners (e.g. body weight of 350 pounds).
• Refusal to give consent to investigator to communicate with treating physician for entire duration of the study.

• Criteria for both Patients with Schizophrenia and Healthy Controls:
• Age of 18 years and older
• Willing to consent to study procedures
  • Criteria for Patients with Schizophrenia:
• Inpatients or outpatients ≥18 years of age.
• DSM-V diagnosis of schizophrenia or schizophreniform disorder confirmed using SCID-5.
• Capable of consenting to participate in the research study (MacCAT).
• No exposure to long-acting antipsychotics in the past 6 months and oral antipsychotic-free for at least 2-weeks
• Deemed suitable to receive first-line antipsychotic treatment as standard of care by the treating physician.
  • Criteria for Healthy Controls:
• Absence of history of psychiatric illness using the SCID-5
• Do not have any first-degree family members with a primary psychotic disorder.
• Are willing to attend appointments reliably.
• Are capable of providing consent