Despite the widespread use of nicotine replacement therapies for the treatment of nicotine dependence, many smokers are still unable to quit smoking. The purpose of this study is to determine the safety and effectiveness of selegiline as an aid to help smokers quit smoking.

Despite the availability of nicotine replacement therapies and sustained-relapse bupropion for the treatment of nicotine dependence, there is still a significant proportion of cigarette smokers who are unable to quit smoking. Therefore, new and effective pharmacotherapies for smoking cessation are needed. The primary aim of this study is to determine the safety and efficacy of selegiline as an aid to smoking cessation.

In this study, 200 nicotine-dependent cigarette smokers will participate in an 8-week, double-blind, placebo-controlled trial and then will be followed over 4 years. Participants will be randomly assigned to receive either selegiline or placebo. Selegiline doses of 5 mg will be taken once a day during the first week. This will be increased to 5 mg twice daily for the remaining 7 weeks. The target smoking "quit date" will be Day 15. All smokers will receive brief weekly manualized smoking cessation counseling from the Mayo Clinic's "Smoke Free and Livin' It" program. The primary smoking cessation outcome measure will be 7-day point prevalence smoking abstinence at the 6-month follow-up. Secondary cessation outcome measures will include continuous smoking abstinence during the last four weeks of the trial (Days 29-56) and 7-day point prevalence abstinence at the end of the 8-week trial (Days 49-56).

Inclusion Criteria:

• Meets DSM-IV criteria for nicotine dependence with a Fagerstrom Test of Nicotine Dependence (FTND) score greater than 5
• Smokes at least 15 cigarettes daily (averaged over 1 week, within the month prior to enrollment)
• Motivated to quit smoking within 30 days at time of initial evaluation
• At least one unsuccessful attempt to quit smoking in the past year
• An expired breath CO level greater than 10 ppm and baseline plasma cotinine level greater than 150 ng/ml at initial evaluation
• Body weight of at least 100 lb
• Avoidance of nicotine replacement product use one month prior to enrollment
• Speaks English

Exclusion Criteria:

• Currently taking over-the-counter or prescription sympathomimetic agents (e.g., pseudoephedrine, methylphenidate), antidepressant agents (e.g., tricyclic antidepressants, serotonin reuptake inhibitors, bupropion, other monoamine oxidase inhibitors), or meperidine (Demerol)
• Serious medical disorders such as unstable angina or liver failure
• Abnormalities in baseline bloodwork (e.g., threefold elevation of liver function tests, electrolyte abnormalities)
• Physiologically dependent on and/or abusing alcohol or other drugs of abuse (e.g., cocaine, opiates, benzodiazepines, etc.) during the 6 months prior to enrollment (based on a clinical evaluation, which includes a self-report, and is confirmed by a positive urine toxicology screen)
• Meets DSM-IV criteria for a current diagnosis of major depressive disorder, panic disorder, or post-traumatic stress disorder
• Current or past history of bipolar disorder or schizophrenia
• Past history of major depression associated with historical evidence of suicidal or homicidal behavior, or psychotic symptoms
• Currently residing with another study participant
• Presence of suicidal or homicidal ideation
• Significant impairment of social or occupational functioning, either at time of initial evaluation or during the trial
• Known hypersensitivity to selegiline hydrochloride