Eligibility Details:
- INCLUSION CRITERIA:
All Subjects must:
- Be between the ages of 18-65.
- Be right-handed. Assessment tool(s): Edinburgh Handedness Inventory.
- Be in good health. Justification: Many illnesses may alter fMRI signals as well as
cognitive processes and neural functioning. Assessment tool(s): Participants will
provide a brief health history during phone screening, and undergo a medical history
and physical examination with a qualified IRP clinician.
- Be free of current moderate to severe DSM-V Substance Use Disorder on any drug, except
nicotine in smokers. Those with past moderate to severe use disorder on substances may
be included, provided they are in sustained remission (and not on maintenance therapy
for opioid use disorder) and are not intoxicated on the day of the imaging session.
Justification: Moderate to severe use disorder on other substances may result in
unique CNS deficits that could confound results and introduce excessive variance,
while mild substance use disorder and substance use disorder in remission are common
in community samples of smokers. Assessment tool(s): Computerized SCID or comparable
assessment and DSM-5 substance use disorder assessment.
- Be able to abstain from alcohol and other recreational drugs for 24 hours before each
imaging session, and able to moderate caffeine intake 12 hours before each imaging
session. Justification: Recent substance use, including alcohol, and caffeine modulate
neural functioning in a way that would complicate data interpretation. Assessment
tool(s): Self-report, breathalyzer, and urine toxicology screen with follow up
neuromotor assessment to ensure absence of acute impairment with positive urine test.
- Smokers must meet the additional criteria:
- Have a urine cotinine (NicAlert) level of 4 or higher and have been smoking for
at least 1 year. Justification: The present protocol is interested in
neurobiological mechanisms that underlie nicotine withdrawal, and is thus
contingent on the presence of nicotine dependence. Assessment tool(s):
Selfreport, NicAlert of 4 or higher
- Be able to abstain from smoking for 12 hours prior to MRI-tDCS study sessions.
Justification: The present protocol will investigate the effect of acute nicotine
withdrawal on cognitive processes and response to tDCS. Assessment: Self-report
and expired CO levels
- In addition, non-smokers must meet:
- Not have a history of daily cigarette smoking or have used any nicotine products
continuously lasting more than a month, and no smoking or continuous use of any
nicotine products within the past year. Assessment Tools: Self-report, NicAlert,
and expired CO levels.
EXCLUSION CRITERIA:
All participants will be excluded if they:
- Are not suitable to undergo an fMRI experiment due to certain implanted 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. 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.
- Have 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 one hour.
Therefore, conditions that would make that difficult (e.g. chronic back pain,
significant scoliosis) 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.
- Have HIV or Syphilis. Justification: HIV and Syphilis both can have central nervous
system (CNS) sequelae, thus introducing unnecessary variability into the data.
Assessment tool(s): Oral HIV followed by blood test if oral test is + and STS+ without
adequate prior treatment
- Regularly or intermittently use any prescription (e.g., benzodiazepines,
barbiturates), over-the-counter (e.g., cold medicine) medications that are likely to
alter BOLD signal (neuronal-vascular coupling). Justification: The use of these
substances may alter the fMRI signal and/or neural functions of interest in the
current study. Assessment tool(s): History and comprehensive urine drug screening to
detect benzodiazepines, antipsychotics, anticonvulsants, and barbiturates. Note: If a
participant is intermittently taking a medication likely to affect BOLD signal, the
participant may be excluded or if scanned, will be scanned in the same medication
state for data continuity purposes (i.e. either all scan days are scheduled after 5
half-lives since last medication use; or all scan days are scheduled on medication).
- Have any current neurological illnesses including, but not limited to, seizure
disorders, frequent migraines or on prophylaxis, multiple sclerosis, cerebrovascular
accident, movement disorders (except essential tremor, so long as it would not
interfere with study tasks such as button pressing), history of significant head
trauma, or CNS tumor. Justification: Neurological diseases alter CNS function and,
possibly, the neuronal-vascular coupling that forms the basis of the fMRI signal.
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 30 minutes or with post-concussive
sequelae lasting more than two days, regardless of loss of consciousness, will be
exclusionary. The MAI who will also retain discretion to exclude based on a history of
neurological illness that may compromise data integrity.
- Have current major psychotic disorders, mania, substance-induced psychiatric
disorders, or any current suicidal ideations or history of suicide attempts. Moderate
to severe current symptoms of mood or anxiety disorders will be exclusionary as well.
However, mild mood or anxiety disorder symptoms will not be exclusionary, whether
medicated or unmedicated. The MAI will reserve the right to exclude on the basis of
psychiatric history not explicitly described in this criterion. Justification:
Psychiatric disorders involve the central neural system (CNS) and, therefore, can be
expected to alter the fMRI measures being used in this study, however, some degree of
mood and anxiety symptoms are common in community samples of smokers. Assessment
tool(s): Computerized SCID or comparable assessment, and clinical interview
confirmation by clinician.
- Are cognitively impaired or learning disabled. Justification: Cognitive impairment and
learning disabilities may be associated with altered brain functioning in regions
recruited during laboratory task performance. Cognitive impairment may affect one s
ability to give informed consent. Assessment tool(s): History of placement in
special-education classes as a consequence of serious learning problems and not solely
as a consequence of behavioral problems, assessed during the History and Physical
screening assessment.
- Have significant cardiovascular conditions that would make use of nicotine patch
unsafe. Justification: Nicotine patch may cause significant arrhythmias in susceptible
individuals. Assessment tool(s): History and physical exam, including 12-lead EKG.
- Have any other major medical condition, such as diabetes mellitus, that in the view of
the investigators would compromise the safety of an individual during participation,
or the quality of data obtainable. Justification: Many illnesses not explicitly
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 lab values will result in exclusion from the study:
i. Hemoglobin < 10 g/dl
ii. White Blood Cell Count < 2400/microl
iii. Liver Function Tests > 3X upper limit of normal
iv. Serum glucose > 200 mg/dl
v. Urine protein > 2+
vi. Serum creatinine > 2 mg/dl
The MAI will retain discretion to exclude based on less extreme lab results. After the
screening process has been completed, the MAI will take into account all data collected in
order to decide if there is an existing medical illness that would compromise participation
in this research.
- Pregnant, planning to become pregnant, or breastfeeding. Females are instructed in the
consent to use effective forms of birth control during the study period.
Justification: study procedures and drugs used in the current protocol may complicate
pregnancy or be transferred to nursing children. Assessment tool(s): Urine and/or
serum pregnancy tests, and clinical interview. Urine pregnancy tests will be conducted
at the beginning of each imaging visit.
- The following exclusion criteria are new for the tDCS study:
- Participated in any brain stimulation session less than two weeks ago, or
underwent brain stimulation exposure for treatment purposes in the last 6 months,
including tDCS or transcranial magnetic stimulation (TMS). Justification: Prior
exposure to brain stimulation may result in carry-over effects that could
confound the results of this study. Participants may enroll in the study once the
listed time periods have passed. Assessment tool(s): Participant medical history
and physical (H&P).
common.study.methods.has-drugs-no
common.study.methods.is-healthy-no
