The Neural Basis of Cue-Elicited Cigarette Craving and Its Control

Objective: Drug craving is a motivational state associated with a conscious desire to consume
a drug (Fredrickson et al., 1995; Drummond, 2001). When drug abusers see drug-related cues,
cue-elicited drug craving is induced (Drummond, 2001). The main goal of this investigation is
to ascertain the neural basis of cue-elicited drug (e.g. cigarette) craving and its control
in smokers.

Study population: The experimental population for this investigation is nicotine-dependent
adults aged 18-50 years old.

Design: Participants will see the smoking-related cue or neutral cue and complete cognitive
tasks (e.g. to report or regulate their craving, etc). At same time, we will employ
functional magnetic resonance imaging (fMRI), real-time functional magnetic resonance imaging
(rtfMRI), and electroencephalography (EEG) to measure brain activity.

Outcome measures: There is no direct benefit to the participant by joining this study. Data
from this study are expected to contribute to a better understanding of the neural processes
of cigarette craving. Thus, the results may benefit the health of society. MRI-related risks
(e.g., injury from metal implants, claustrophobia, and temporary hearing threshold
alterations due to the loud banging noises) and nicotine-patch-related risks (e.g.,
dizziness, headache, upset stomach, vomiting, diarrhea, redness or swelling at the patch
site) to participants are minimized by careful prescreening and standard protection.

- INCLUSION CRITERIA:

All participants must:

1. Be between the ages of 18-50. Justification: Many cognitive processes change with age.
In addition, the risk of difficult-to-detect medical abnormalities such as silent
cerebral infarcts increases with age. Therefore, older individuals, defined as those
over 50, will be excluded.

2. Be in good health. Justification: Many illnesses can alter fMRI signal, and cognition.
Assessment tool(s): Participants will provide a brief health history during phone
screening, and undergo a history and physical examination with a qualified IRP
clinician.

3. Be right-handed. Justification: Many of the brain functions to be assessed in this
protocol have shown some evidence of being lateralized in the brain. In order to
reduce the variance in the data from this possibility, participants must be
right-handed. Assessment tool(s): Edinburgh Handedness Inventory

4. Be free of dependence on other substances (except nicotine). Justification: Dependence
on other substances may result in unique CNS deficits that would increase the noise in
our data. Assessment tool(s): Substance Use Disorders module of the SCID with
confirmation by clinical interview and negative urine drug screen.

5. Must smoke greater than or equal to 10 cigarettes per day for at least two years, with
urine cotinine levels of at least 100ng/ml and score on the Fagerstrom Test for
Nicotine Dependence (FTND) must be greater than or equal to 2. Justification: The aim
is to study phenomena that are linked to nicotine dependence and that occur with
regular and frequent smoking. Assessment tool(s): Self-report, a urine cotinine test
(smokers will be defined as having cotinine levels greater than or equal to 100ng/mL),
and FTND test.

6. All participants should be able to abstain from alcohol for 24 hours and no more than
1/2 cup of caffeine for 12 hours before each experiment session. Justification:
Alcohol and caffeine may result in brain that influences our data. Assessment tool(s):
Self-report and breathalyzer test.

EXCLUSION CRITERIA:

Participants will be excluded if they:

1. Are not suitable to undergo an fMRI experiment due to pregnancy, implanted metallic
devices (cardiac pacemaker or neurostimulator, some artificial joints, metal pins,
surgical clips or other implanted metal parts), body morphology or claustrophobia.
Justification: MR scanning is one of the primary measurement tools used in the
protocol. Assessment tool(s): Prospective participants will fill out an MRI screening
questionnaire and undergo an interview with an MR technologist. Pregnancy tests will
be performed on all female participants of childbearing age before each experimental
session. Questions concerning suitability for scanning will be referred to the MR
Medical Safety Officer. Prospective participants will be questioned about symptoms of
claustrophobia and placed in the mock scanner during their first visit to assess for
possible difficulty tolerating the confinement of the scanner and for ability to fit
into the scanner.

2. Have coagulopathies, history of, current superficial, or deep vein thrombosis,
musculoskeletal abnormalities restricting an individual s ability to lie flat for
extended periods of time. Justification: MR scanning sessions require participants to
lie flat on their backs and remain perfectly still for approximately two hours.
Therefore, conditions that would make that difficult (e.g. chronic back pain,
significant scoliosis) or dangerous (e.g. familial hypercoagulability syndrome,
history of thrombosis) will be exclusionary. Assessment tool(s): History and physical
examination by a qualified IRP clinician, supplemented with a trial of lying in the
mock scanner to assess comfort issues.

3. Have HIV or Syphilis. Justification: HIV and Syphilis can both have CNS sequelae, thus
introducing unnecessary variability into the data. Assessment tool(s): HIV blood test
and RPR+.

4. Have any neurological illnesses to include, but not limited to, seizure disorders,
migraine (>2/yr or on prophylaxis), multiple sclerosis, movement disorders, or history
of significant head trauma, CVA, CNS tumor. Justification: CNS diseases alter CNS
function and, possibly, the neuronal-vascular coupling that forms the basis of the
BOLD fMRI signal to be used in this study. Assessment tool(s): History and physical
examination by a qualified IRP clinician, urine drug screening for anticonvulsants not
disclosed by history. History of head trauma with loss of consciousness of more than 5
minutes or with post-concussive sequelae lasting more than two days, regardless of
loss of consciousness, will be exclusionary.

5. Have other major medical illnesses likely to interfere with study results or safety of
an individual during participation. Justification: Many illness not covered here may
increase risk or alter important outcome measures. Assessment tool(s): History and
physical examination by a qualified IRP clinician and CBC, urinalysis, NIDA chemistry
panel (liver function tests, electrolytes, kidney function). The following individual
laboratory results will independently disqualify individuals. The MRP will retain
discretion to exclude at less extreme values, depending on the clinical presentation,
and will make the final judgment on any questionable lab results

- Hemoglobin < 10 g/dl

- WBC < 2400/microl

- LFTs > 3 times normal

- HCG positive

- Serum glucose > 200 mg/dl

- Urine protein > 2 plus

- Serum cholesterol level> 250 mg/dl.

6. Have any current major psychiatric disorders to include, but not limited to, mood,
anxiety, psychotic disorders, or substance-induced psychiatric disorders.
Justification: Psychiatric disorders involve the central neural system (CNS) and,
therefore, can be expected to alter the fMRI measures being used in this study.
Assessment tool(s): Computerized SCID-NP, ASRS (adult ADHD self-report scale) and
DSM-IV (DSM-IV, APA, 1994) confirmed by clinician interview.

7. Regularly use any prescription, over-the-counter or herbal medication that may alter
CNS function, cardiovascular function or neuronal-vascular coupling. Justification:
Compounds that alter BOLD signal will alter the primary measure used in the study.
Assessment tool(s): History and comprehensive urine drug screening to detect
antidepressants, benzodiazepines, antipsychotics, anticonvulsants, barbiturates and
other common medications and drugs of abuse.

8. Are cognitively impaired or learning disabled. Justification: Cognitive impairment and
learning disabilities are associated with alterations in brain regions used to
accomplish tasks, and, therefore, may introduce significant variably into the data. In
addition, cognitive impairment may affect ability to give informed consent. Assessment
tool(s): History of known learning disability or cognitive impairment. Vocabulary
subtest of the WASI will be given. IQ estimate must be over 85 (corresponding to a
vocabulary subtest score > 48). In cases of suspected non-verbal learning disability
or mild verbal deficit, a full WASI may be given to obtain a more robust estimate of
IQ.

9. Significant cardiovascular or cerebrovascular diseases. Justification: Such conditions
can alter and distort BOLD and autonomic signals and increase the risks associated
with nicotine patch use. Assessment tool(s): History and physical exam, including
12-lead ECG.