Please select the eligibility criteria that correspond to the clinical trial below.
Title: Varenicline for Long-term Nicotine Replacement Therapy (NRT) Users. A Double Blind, Placebo Controlled Trial
Brief Summary: Primary aim: Will varenicline be better than placebo to get long-term users of NRT to stop?

Secondary aim: To assess in details some side effects of varenicline i.e. nausea and abnormal dreams.


Options:
A: Inclusion Criteria:

* Age 18-60
* DSM-IV Diagnosis of schizophrenia, schizoaffective disorder, or schizophreniform disorder
* Clinically stable with no change in antipsychotic medications and increase of daily dose for 4 weeks prior to enrollment
* Sufficient understanding of the study and risks (ESC score 10 or above)

Exclusion Criteria:

* Major medical illness history including, but not limited to, history of heart attack, stroke, TIA (transient ischemic attack)
* History of organic brain disorders that may affect neurophysiological measurements, including seizure disorder, brain tumor, head injury with evidence of significant cognitive deterioration
* DSM-IV diagnosis of substance dependence within 6 months except nicotine and marijuana
* On nicotine replacement therapy (nicotine patch, gum, or nasal spray)
* Uncontrolled blood pressure (persistent systolic above 155 or diastolic above 95)
* EKG of second or third degree atrioventricular (AV) block
* Renal insufficiency with estimated creatinine clearance \<40 ml/min
* Women who have positive urine pregnancy tests
* Women who are pregnant, plan to become pregnant, or in breastfeeding
B: Inclusion Criteria:

* Long-term, daily NRT users (except nicotine patch) (\>11 months) ex-smokers that are willing to try to stop the use of NRT and adhere to this protocol.
* More than 4 pieces of nicotine gum/ sublingual tablets/ lozenges/ per day, OR more than 3 inhaler cylinders per day, OR
* more than 10 puffs of nasal spray per day.

Exclusion Criteria:

* Age \< 18 years,
* CO Smokers,
* Pregnant and lactating women,
* Used varenicline before,
* Not able to cooperate,
* Other significant diseases that might influence the trial (such as moderate -severe cardiac disease, lung cancer,) in expired air \> 7 ppm.
C: Inclusion Criteria:

1. HIV positive
2. Adult (aged 18 or older)
3. Current smoker (more than 5 cigarettes per day)
4. Willing to set a date to quit smoking within the next 2-4 weeks
5. Currently on ART with an undetectable HIV viral load
6. Able to read/speak English or French
7. Able to provide written, informed consent as approved by the Ottawa Health Science Network Research Ethics Board and REBs at participating HIV clinic sites

Exclusion Criteria:

1. Contraindications to nicotine replacement therapy such as allergy to adhesive, serious cardiac arrhythmias (e.g., tachycardia), or vasospastic disease (e.g., Buerger's disease, Prinzmetal's variant angina)
2. Contraindications to varenicline such as hypersensitivity to varenicline or to any ingredient in the formulation or component of the container.
3. Reported previous severe intolerances to nausea or gastrointestinal symptoms.
4. Pregnant, lactating or planning to become pregnant during the study period or refuses a serum beta-HCG test.
5. Current severe renal impairment or currently taking Cimetidine
6. Previous or current seizure disorder and/or is taking anti-epileptic drugs
7. Psychosis and/or is taking anti-psychotic drugs
8. Diagnosed with severe major depressive episode requiring hospitalization within the past 12 months, previous psychiatric inpatient admission for any cause within the past 12 months, suicide attempt within the past 12 months active or current suicidal ideations as assessed by the BDI-II.
9. Current use of bupropion, varenicline or any nicotine replacement therapy.
10. Use of substances (e.g., crack cocaine) that would interfere with a participant's ability to adhere to the study schedule; determined by site coordinator's discretion.
D: Inclusion Criteria:

1. Regular cigarette smokers smoking at least 5 cigarettes per day as derived by Time-Line Follow-Back method (Sobell et al., 1988). Average number of cigarettes per day (over past 30 days) will be used. Five cigarettes per day may seem low, but based on previous studies, adolescents tend to smoke fewer cigarettes per day as compared to adults.
2. Baseline urine cotinine level greater than 100 ng/ml.
3. Age range of 12 - 21
4. If under 18 yr. of age, parent(s) or guardian(s) able to participate in informed consent and initial assessment, or the participant must provide evidence of emancipated status.
5. For post menarchal female participants: agree to use birth control to avoid pregnancy.

Exclusion Criteria:

1. Active substance abuse/dependence (other than nicotine) within 2 weeks prior to participating in the study
2. Lifetime bipolar affective disorder (BPAD), psychosis, eating disorders. Bupropion may have adverse consequence on participants with these psychiatric diagnoses.
3. Current major depressive disorders. Since bupropion is also an antidepressant, this criteria is to minimize the confound of depressive disorder during the study. History of depressive disorders and current attention deficit hyperactivity disorder (ADHD) will not be an exclusion. We will use permuted block randomization procedure to balance the groups for ADHD.
4. Pregnancy or lactation. The safety of bupropion in pregnancy and during lactation is not well studied.
5. History of seizure disorder or predisposition to seizures (e.g., history of significant head trauma, currently taking medications that lower seizure threshold), since bupropion can lower seizure threshold.
6. History of severe renal, hepatic, neurological, or chronic pulmonary disease. This criterion was chosen due to the hepatic metabolism of bupropion.
7. Unstable medical problems
8. Allergy to bupropion
9. Current treatment with any other medication containing bupropion
10. Current treatment with any monoamine oxidase (MAO) inhibitors currently or within 2 weeks of starting the study since there may be serious and severe medical interactions between MAO inhibitors and bupropion SR.
11. Current treatment with nicotine replacement therapy (NRT)
12. History of intolerance or non-response to bupropion SR.
13. Current (past month) suicide ideation
14. Suicide attempt (past year)

Answer: B