Please assess the completion status of the following clinical trial:

Trial Title: The Effect of Varenicline on D2/D3 Receptor Binding in Smokers

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: BASIC_SCIENCE
- Time Perspective: None
- Masking: NONE
- Phase: None
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~* Subjects will be nicotine dependent, males and females of any ethnic origin between 21 and 45 years old.~* Meet DSM-IV criteria for nicotine dependence,~* Smoke ≥10 cigarettes/day, Baseline FTND score ≥4, CO level ≥10 and are motivated to quit within 30 days of initial intake.~* Treatment seeking smokers that are willing to use varenicline as a treatment approach for their smoking cessation attempt~* No previous use of medication for smoking cessation in previous month prior inclusion.~Exclusion Criteria:~* Pregnancy (a urine pregnancy test will be performed before each PET in women)~* Trying to become pregnant or breastfeeding;~* Have abused alcohol or other drugs of abuse (cocaine, opiates, benzodiazepines, etc) in 3 months prior to randomization.~* Presence of metal objects in the body (e.g. some artificial joints, bone pins, surgical clips, skull plate, certain part of dental braces) or implanted electronic devices (e.g. cardiac pacemaker, neurostimulator), that preclude safe MR scanning.~* Claustrophobia.~* Cardiovascular or cerebrovascular diseases.~* Major psychiatric disorders including mood, anxiety or psychotic disorders with historical evidence of suicidal or homicidal behaviour.~* History of or current neurological illnesses including seizure disorders, migraine, multiple sclerosis, movement disorders, head trauma, CVA or CNS tumor. Gross structural brain abnormalities as revealed by T1 weighted images.~* Current use or use during the previous month of medication that may affect the CNS at the time of scanning (including illicit and non-illicit psychoactive drugs).~* Learning disability, amnesia or other conditions that impede memory and attention.~* Allergy to varenicline.~* Renal insufficiency.~* Use of other smoking cessation aids

- Gender: ALL
- Minimum Age: 21 Years
- Maximum Age: 45 Years
- Healthy Volunteers: f

Study Arms:
- Varenicline (Type: EXPERIMENTAL): Varenicline will be used at the same dosage regimen as used for smoking cessation, i.e. 0.5mg once daily for days 1-3, 0.5mg twice daily for days 4-7 followed by 1mg twice daily. The total duration of Varenicline treatment will be three months.

Based on this trial design, predict the completion outcome and termination type (if applicable).