en Medicine پژوهشي Research <div style="text-align: justify;"><strong>Background:</strong> Addiction (drug dependence) is a health problem in many countries. In Iran, drug abuse is one of the most important preventable health problems. Comorbidity of drug abuse with other disorders is also a barrier to treatment of addicts, in a way that more than 70% of addicts suffer from mental and physical disorders. Therefore, we performed this comparative study to investigate the comorbidity of mental disorders in drug-dependent and non-dependent individuals referred to the addiction rehab center of 5^th Azar Hospital in Gorgan, in 2016. <strong>Materials and Methods:</strong> The study was performed on 130 male drug addicts and 130 male healthy controls through available sampling. Structured interviews for drug dependence testing (based on the DSM-V-TR criteria) and the symptom checklist-90-Revised (SCL-90-R) were used to assess the mental status of the subjects. Data were analyzed using SPSS (version 16) via t-test, man-witny, chi-square and Shapiro-Wilk. The significance level (P) was set at 0.05 and validity and reliability of the material were evaluated in a pilot investigating. <strong>Results: </strong>The subjects with drug-dependence scored higher in all scales related to mental disorders compared with the control group. The frequency of symptoms including somatization (56.9%), obsessive-compulsive disorder (61.5%), interpersonal sensitivity (62.3%), depression (66.2%), anxiety (59.2%), hostility (42.3%), phobia (34.5%), paranoid ideation (62.6%), and psychoticism (56.9%) was higher in subjects with drug addiction. <strong>Conclusion:</strong> The results of this study indicate that the frequency of psychopathological symptoms and mental disorders is significantly higher in drug-dependent individuals compared with the normal population.</div> Mental disorders, drug dependence, comorbidity, mental health, behavior 31 35 http://jcbr.goums.ac.ir/browse.php?a_code=A-10-31-4&slc_lang=en&sid=1 Seyyed-Mohsen Hosseininejad سید محسن حسینی نژاد 10031947532846001684 10031947532846001684 No Golestan University of Medical Sciences Ahmad Gharanjik احمد قرنجیک 10031947532846001685 10031947532846001685 No Golestan University of Medical Sciences Sadeghali Taziki صادقعلی تازیکی 10031947532846001686 10031947532846001686 No Golestan University of Medical Sciences Soheyla Kalantari سهیلا کلانتری 10031947532846001687 10031947532846001687 No Golestan University of Medical Sciences Fatemeh-Sadat Hosseininejad فاطمه سادات حسینی نژاد 10031947532846001688 10031947532846001688 No Shahrood University of Medical Sciences Amirhossein Salimi Kordasiabi امیر حسین سلیمی کرد آسیابی 10031947532846001689 10031947532846001689 Yes Golestan University of Medical Sciences