Nicotinic Receptor Density in Smoking and Nonsmoking Schizophrenics

Schizophrenia Clinical Trial

Official title: PET Assay of Acetylcholine Beta2* Nicotinic Receptor Density in Smoking and Non-Smoking Schizophrenics

Status Withdrawn

Clinical Trial Summary

Background:

• Previous studies have suggested that smoking cigarettes affects the number of receptors in the brain for nicotine, a chemical present in cigarette smoke. The receptors play a role in an individual's ability to think and concentrate. Many people with schizophrenia and similar disorders smoke, and research suggests that smoking may temporarily improve concentration and focus in individuals with schizophrenia. Researchers are interested in studying both current smokers and nonsmokers with schizophrenia to determine whether smoking affects the number of nicotine receptors in the brains of people with schizophrenia.

Objectives:

• To study the distribution and volume of nicotine receptors in the brains of individuals with schizophrenia who are either nonsmokers or current smokers.

Eligibility:

• Individuals between 18 and 50 years of age who have been diagnosed with schizophrenia and are either nonsmokers or current smokers (at least 10 cigarettes per day for the past year).

• Current smokers must be able to give up smoking for 48 hours.

Design:

• This study involves an initial screening visit and up to five study visits.

• After the screening visit, participants will have two sessions in which they will complete questionnaires about thoughts, memory, and smoking habits. Smokers will also have nicotine blood and carbon monoxide breath levels taken during these sessions, before and after smoking a cigarette.

• Participants will have sessions with imaging studies (e.g., magnetic resonance imaging) to provide baseline measurements for later tests, and will also have tests to measure brain electrical activity.

• Participants will have a positron emission tomography (PET) scanning session to examine the nicotine receptors in the brain. Participants will need to stay overnight (nonsmokers) or for 2 nights (smokers) as an inpatient before the session. The PET scan session will take up to 6 hours, although participants will only be in the scanner for up to 3 hours.

• Participants will have a follow-up phone call with study researchers 1 week after the PET scanning session.

Clinical Trial Description

Objective:

The objective of this study is to determine the distribution and volume of distribution (Vt) in vivo of Beta2* acetylcholine receptors (Beta2* nAChR) in schizophrenic smokers and nonsmokers and compare this to published data from normal healthy subjects who are smokers and nonsmokers.

Study population:

Participants will be volunteers with a diagnosis of schizophrenia aged 18 to 50 years. The proposed sample size is 10 per group: nonsmokers or ex-smokers and smokers for a total of 20 participants.

Design:

One PET study lasting up to 8 hours after combination of bolus and continuous infusion administration of 2[(18)F] FA-85380. Smokers will be abstinent for at least 48 hrs. Subjects will also undergo a structural MRI scan for purposes of registration of PET scan data.

Outcome Measures:

Data from 20 schizophrenic patients (10 smokers and 10 nonsmokers) will be compared to published data from healthy controls. Total volume of distribution (VT) which is a measure of receptor density and distribution of Beta2 nAChR* will be determined in Schizophrenic smokers and nonsmokers and differences in these values will be compared to published values for the differences in nicotinic acetylcholine receptor density in healthy smokers and nonsmokers (Mukhin et al., 2008) Also, receptor distribution and VT will be correlated with levels of smoking and symptom profiles in the schizophrenic patients studied. ;

Related Conditions & MeSH terms

• Schizophrenia

• NCT number: NCT01246128
• Study type: Observational
• Source: National Institutes of Health Clinical Center (CC)
• Status: Withdrawn
• Phase: N/A
• Start date: October 31, 2010
• Completion date: July 12, 2011