Nicotine dependence, psychological distress and personality traits as possible predictors of smoking cessation

Background: Nicotine replacement therapy (NRT) is an effective treatment for smokers who want to quit ( Stead et al. 2005), however the rates of successful quitting can still be improved. In this frame, nicotine dependence, personality traits, psychological distress and withdrawal symptoms were evaluated as possible predictors of smoking cessation. Materials and Methods: the study is part of a NRT double-blind, parallel group, randomised trial (Paoletti et al. 1996). Smokers were divided into two treatment groups: the low and the high cotinine group based on their baseline cotinine plasma values (cut off 250 ng/ml). Smokers in the LC group were randomly assigned to placebo or to a 15-mg nicotine patch. Smokers in the HC group were randomly assigned to a 15- or 25-mg nicotine patch. At baseline, nicotine dependence was assessed via the Fagerström Tolerance Questionnaire (FTQ), personality traits via the Adult Eysenck Personality Inventory (AEPI), distress and psychiatric symptoms via the Symptom Rating Test (SRT). At follow up visits (week 12, 26 and 52) subjects were asked about withdrawal symptoms and filled again the Symptom Rating Scale. A multivariate logistic regression analysis was performed to identify independent predictors of tobacco abstinence. FTQ and AEPI subscale scores were the independent variables. Three, six, or twelve months abstinence status was the dependent variable. Indicator variables for treatment received were included in the model. When SRT was evaluated, an analysis of the odds of failure to quit smoking during the follow-up was conducted using a random-effects generalized estimating equations model. FTQ and treatment received were included in the model and tested for statistical significance. Results: A total of 297 cigarette smokers were followed for one year as part of a NRT double-blind, parallel group, randomized trial. Baseline nicotine dependence (weeks 12 and 26: p < 0.05), AEPI neuroticism (weeks 12 and 52: p < 0.05), and AEPI psychoticism (weeks 12 and 52: p < 0.05) scores significantly influenced the outcome of smoking cessation during one – year of follow-up. An increase in psychological distress during follow-up was associated with a lower probability of quitting smoking (p = 0.000). Discussion: Nicotine dependence, neuroticism, psychoticism and, over time, psychological distress were the main factors influencing the long-term outcome (i.e., up to 12 months) of smoking cessation under NRT.