Rationale. Changes in dopamine level are thought to play an important role in both smoking reward and withdrawal symptoms during abstinence. Medications that modulate dopamine levels may have beneficial effects on both withdrawal symptom levels and on response to smoking lapses during abstinence.

Objectives. To examine the effects of the selective MAO-B inhibitor selegiline on withdrawal symptoms, smoking behavior and smoking satisfaction ratings.

Methods. Fifteen smokers received selegiline (10 mg/day) and placebo (in counterbalanced order) on Monday through Thursday of 2 study weeks, separated by a 2-week washout. During each study week, ad lib smoking sessions were scheduled to assess smoking behavior both before and after a brief period of abstinence. Subjective withdrawal symptoms and mood were measured daily, and a modified Stroop test sensitive to withdrawal was scheduled during the period of abstinence.

Results. Selegiline decreased craving, especially during abstinence, and impaired performance on the modified Stroop test during subjects' attempts to abstain. Medication also reduced number of cigarettes smoked and smoking satisfaction ratings during the smoking sessions both before and after the brief abstinence attempt.

Conclusion. These results are consistent with an important role of dopamine in smoking behavior and abstinence. They suggest that pharmacological reduction of MAO-B levels during the early part of a quit attempt may aid in smoking cessation.