substance use among students of guilan university of medical sciences in iran in 2005-2006

population pattern in guilan province represents a dramatic increase in youth population. regarding high prevalence of substance use among them, its destructive effects and consequences and paucity of previous related studies, this research was performed to determine the prevalence of substance use among students of guilan university of medical sciences (gums). we conducted a cross-sectional study in a representative sample of 845 students in 2005-2006. data were collected by a questionnaire including demographic data and history of substance use and were analyzed by epi 2002 software and chi-square. 30.1% of students had a history of substance use at least once during their lives. cigarette (26.36%), alcohol (17.04%) and opium (3.86%) were the most prevalent used substances. substance use was significantly associated with male gender, higher age groups, living with friends or alone and being married. there were significant relationships between substance use during past 30 days and studying medicine or dentistry and substance use during life and past 30 days was significantly higher in residency period. this study demonstrated substance use between our samples was considerable and specific interventions to reduce it seem necessary.