Nicotinic Receptor Density in Smoking and Nonsmoking Schizophrenics

Status:	Archived
Conditions:	Schizophrenia
Therapuetic Areas:	Psychiatry / Psychology
Healthy:	No
Age Range:	Any
Updated:	7/1/2011
Start Date:	October 2010

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

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.

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.

We found this trial at

sites

Johns Hopkins University

3400 N Charles St
Baltimore, Maryland 21205

410-516-8000