BackgroundThe lack of conclusive results and the scarce use of the Millon Clinical Multiaxial Inventory-III (MCMI-III) in the study of the relationship between smoking and personality are the reasons that motivated the study reported here. The aim of the present study was to analyze the influence of personality patterns, assessed with the MCMI-III, and of nicotine dependence on treatment outcomes at the end of the treatment and at 12 months follow-up in men and women smokers receiving cognitive-behavioral treatment for smoking cessation.MethodsThe sample was made up of 288 smokers who received cognitive-behavioral treatment for smoking cessation. Personality patterns were assessed with the Millon Clinical Multiaxial Inventory-III (MCMI-III). Abstinence at the end of the treatment and at 12-month follow-up was validated with the test for carbon monoxide in expired air.ResultsThe results showed significant differences by personality patterns that predict nicotine dependence (Narcissistic and Antisocial in men and Schizoid in women). At the end of the treatment it is more likely that quit smoking males with a Compulsive pattern and less likely in those scoring high in Depressive, Antisocial, Sadistic, Negativistic, Masochistic, Schizotypal and Borderline. In women, it is less likely that quit smoking those with the Schizoid pattern. At 12 months follow-up it is more likely that continue abstinent those males with a high score in the Compulsive pattern. Furthermore, nicotine dependence was an important variable for predicting outcome at the end of the treatment and smoking status at 12 months follow-up in both men and women.ConclusionsWe found substantial differences by gender in some personality patterns in a sample of smokers who received cognitive-behavioral treatment for smoking cessation. We should consider the existence of different personality patterns in men and women who seek treatment for smoking cessation.