Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 9 3 2014 09 15 158 62 Shahin Akhondzadeh Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran Moslem Shabrang Shebli Street, Welfare Organization of Kurdistan Province, Sanandaj, Iran Omid Rezaei Department of Psychiatry, University of Social Welfare and rehabilitation Sciences, Tehran, Iran Farzin Rezaei Department of psychiatry of Kurdistan University of Medical Sciences, Sanandaj-Iran 2015 10 14 Objective: Therapeutic interventions can be classified into two distinct approaches: abstinent and maintenance method. Currently, there are no clear criteria for referring addicted patients to one of these modalities. We aimed to compare the personality characteristics of individuals with addiction who attended narcotics anonymous sessions with those who received methadone maintenance therapy. Methods: This was a cross- sectional study. The participants were NA members and patients who were undergoing methadone maintenance treatment in outpatient clinics. Using the randomized cluster sampling method, 200 individuals with opioid dependence were selected (each group 100 persons). Data were collected through a demographic questionnaire and the five-factor personality inventory (NEO-FFI). Comparison of the mean scores of NEO-PPI in the two groups was performed by independent t test, and qualitative variables were compared using the Chi-square test. Results: We found a significant difference between the MMT and NA roups with respect to neuroticism, extroversion, and agreeableness. No significant difference was found in the subscales of conscientious and openness. Conclusion: People who regularly attended the NA sessions had lower neuroticism and higher agreeableness than patients who were under the maintenance modality. Whether this is the cause or effect of attending NA sessions requires future large-scale cohort studies. https://ijps.tums.ac.ir/index.php/ijps/article/view/47 https://ijps.tums.ac.ir/index.php/ijps/article/download/47/43