Objectives: This study is carried out with the aim of assessing the relationship between craving and impulsivity factors in three main groups of opiate addicts [heroin, crack-heroin (locally known, purified crystaline heroin), and opium]. Method: 77 opiate users in 3 groups [37 heroin intravenous (IV) abusers, 17 crack smokers and 23 opium smokers] were selected using a semi-structured interview and based on dependency criteria of Diagnositic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), from treatment waiting list of

Iranian

National

Center for Clinics Addiction Studies. At first, demographic information was collected from each subject. Computerized version of Barratt and Zuckerman Scales, and Eysenck and Dickman questionnaires were used to assess different aspects of impulsivity. Craving was assessed through a computerized visual cue task for opiate addicts (heroin, heroin-crack, and opium). Results: Results show higher scores in motor and dysfunctional impulsivity among heroin IV abusers than opium smokers and higher experience seeking and boredom susceptibility in heroin-crack smokers. Higher craving was correlated with higher scores in non-planning, motor and cognitive impulsivity, and total Barratt score. Craving scores were negatively correlated with age and functional impulsivity and positively correlated with the total score on Barratt Impulsiveness Scale. Conclusion: Personality features can be important predictive factors for craving severity in addicts. This can help to choose an appropriate treatment and the control of craving which is the most important factor leading to relapse in substance abuse.