• Level of insomnia as measured by the Insomnia Severity Index [ Time Frame: 6 weeks after target smoking quit date ] [ Designated as safety issue: No ]
  

• Smoking abstinence as measured by self reported smoking [ Time Frame: 6 weeks after target smoking quite date ] [ Designated as safety issue: No ]
  
• Smoking abstinence as measured by expired breath carbon monoxide (CO) level [ Time Frame: 6 weeks after target smoking quit date ] [ Designated as safety issue: No ]
  

Inclusion Criteria:

• Are between ages 18-65 years old.
• Meet DSM-IV criteria for nicotine dependence.
• Smoke at least 15 cigarettes (3/4 pack) daily (averaged over 1 week, in the past 1 month) and have an expired breath CO level >10.
• At the time of initial evaluation, are motivated to quit smoking in the next 30 days.
• Receive a score of ≥10 on the Insomnia Severity Index (ISI)
• Have the capacity to give informed consent, and are English-speaking.

Exclusion Criteria:

• Are taking an over-the-counter or prescriptions medications that are known to affect sleep.
• Are taking medications contraindicated for use with eszopiclone or bupropion including: Ketoconazole, Itraconazole, Clarithromycin, Erythromycin, Nefazodone, Troleandomycin, Ritonavir, Nelfinavir, Trazodone, and Methadone.
• Are using any over-the-counter analgesics that contain caffeine.
• Have serious medical disorders that may make participation in the trial unsafe.
• Are physiologically dependent on and/or abusing alcohol or other drugs of abuse (e.g., cocaine, opiates, benzodiazepines, etc.) in the past 6 months prior to randomization into the trial.
• Consume greater than 1 alcoholic beverage per day or greater than 7 alcoholic drinks per week.
• Meet DSM-IV criteria for a current diagnosis of major depressive disorder, panic disorder or post-traumatic stress disorder, or a current or past history bipolar disorder, schizophrenia, or anorexia or bulimia nervosa. Have a past history of major depression, with historical evidence of suicidal or homicidal behavior, or psychotic symptoms.
• Have the presence of suicidal or homicidal ideation, or significant impairment of social or occupational functioning, either at study baseline during the evaluation process, or during participation in the trial
• Are from the same household as another study participant.
• A history of seizures of any etiology
• A history of hypersensitivity to bupropion or Lunesta (eszopiclone).