Although Nicotine replacement therapy (NRT) is an effective treatment for smokers who want to quit, the rates of smoking cessation can be still improved. In an effort to increase these proportions, factors that may influence the occurrence of relapse have been increasingly studied (e.g. pharmacotherapy, socio-demographic characteristics) and there has been a growing interest in psychological and psychiatric clinical factors.

Nicotine dependence (assessed via the Fagerström Tolerance Questionnaire, FTQ), psychological distress (measured via the Symptom Rating Test, SRT), and personality traits (evaluated via the Adult Eysenck Personality Inventory, AEPI) were evaluated as possible predictors of smoking cessation in a sample of 297 cigarette smokers 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).

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. Thus, psychological distress and personality characteristics should be evaluated in smokers who apply for assistance in smoking cessation with the aim to have a complete assessment and propose tailor-made interventions.