nowadays drug abuse and addiction is one of the most important health,social and political problems in the world. substance use among university students is a mental health concern. people with depression have high rates of comorbidity with other mental disorders and substance use disorders. the purpose of this study was to determine the prevalence of depression, substance use and the relationship between depression and substance use among student of guilan university of medical sciences(GUMS).

this was a cross-sectional study carried out on a representative sample of 254 students(n=167girls;n=87boys) of GUMS. The samples were selected randomly by stratified sampling. data was collected using a confidential multiple choice questionnaire detecting the frequency of various substance use. the beck depression inventory(BDI)were used to determine depressive symptoms. Data were analyzed by chi-square and exact fisher test using SPSS ver 16software.

results showed that the prevalence rate of each substance in use was: Opium (1.2%), Morphine (0.4%), cannabis (1.2%), Cocaine (0.4%), codeine (7.5%), Ritalin (2%), tramadol (4.7%) cristal (0.4%), Amphetamines (0.8%),cigarette (8.3%), alcohol(7.1%). according to BDI,(29.9%)of students had depression.there were significant differences between the prevalence of substance use with gender(p=0/0001),parent marital status(p=0/01)and depression(p=0/01).

This study demonstrated that the substance use among students is considerably high and specific interventions seem to be necessary in preventing or reducing the rate of substance use in students. Reading the result of this study,it is suggested that parents and universities authorities have a better over solving students emotional and social problems.