Introduction & Objective: Some researches have shown that 14% of internet users suffer from OCD behaviors, psychosis status, depression, and etc. Also, in other studies characteristics such as social withdrawal, low self esteem, etc have been considered. This study aims to investigate internet addiction and its relationship to psychiatric symptoms.

Materials & Methods: In order to perform this descriptive and cross-sectional research ,a total of 120 students of Isfahan universities was selected based on quota sampling .The samples completed demographic questionnaires, YDQ, Internet Addiction Test(IAT) ,and Symptom Checklist-90-Revision(SCL-90-R). Finally, scores of psychiatric symptoms were predicted by internet addiction scores. Also, mean psychiatric symptoms in internet addicted and non addicted were compared. The data was analyzed using Multiple Logistic Regression & MANCOVA by SPSS12 Software.

Results: Based on our findings ,there are significant differences between mean psychiatric symptoms in all of SCL-90-R subscales and GSI,PSDI,PST in addicted and non addicted (P<0.05). Also, findings showed that there are positive and significant correlation between scores of psychiatric symptoms(such as depression, anxiety, hypochondriasis, OCD, Interpersonal Sensivity, aggression, paranoia, phobia and psychosis) ,and GSI,PSDI,PST and internet addiction.(P<0.01). Also, internet addiction (with controlling sex variable) influences on psychiatric symptoms.

Conclusion: The findings of this research suggest that internet addiction should be considered a serious health problem because of its side effects on the youth. Also, it is necessary for psychiatrists and psychologists practicing in mental health areas to be aware of mental problems due to internet addiction such as anxiety ,depression, aggression, occupationl and educational dissatisfaction