Methods: The study used a causal-comparative research design. The target population included all of those individuals with adoliction to stimulants, opioids and cigarette who were referred to medical centers in Tehran city. The subjects included 120 persons (divided in to 4 groups of 30) and were selected through a purposive sampling method considering the inclusion and exclusion criteria, informed consent, and matched on demographic variables. They completed the Barratt Impulsivity Scale, prospective memory Scale, and demographic Questionnaire. Data were analyzed by descriptive statistics (frequency, percentage, mean and standard deviation) and inferential statistics (multivariate analysis of variance).

Findings: The results showed that the mean of impulsivity and prospective memory in the three addict group was significantly higher than the normal group. The mean of prospective memory [short-term past, long-term future and impulsivity] was significantly higher in stimulant addicts than in the other two groups of addicts. There was no significant difference between the group of opiate addicts and cigarette smokers, in prospective memory and impulsivity.

Conclusion: Based on the results of this study, it can be deduced that prospective memory and impulsivity are important neuropsychological factors in addiction, and depending on the route of usage, have significant differences. Hence it is evident that specific interventions, on the basis of type of addiction, will be necessary.