Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 7 1 2012 03 15 36 40 Reihane Firoozi Department of psychology, University of guilan, Guilan, Iran. Mousa Kafi Iraj Salehi Maryam Shirmohammadi 2015 10 14 Objective: Premenstrual syndrome is a common disorder experienced by up to 50% of women during reproductive age. The prevalence of severe form of PMS (PMDD) is 3 % to 8%. Psychiatric disorders in PMS patients have resulted in significant morbidity and in some cases caused resistance to the treatment process Material and Method: 390 participants (264 with PMS/PMDD, and 126 healthy students of University of Guilan) who completed the demographic questionnaire, daily symptom rating (DSR) and the checklist 90-revised (SCL-90-R) took part in this study. This study was conducted using a cross sectional method. Results: According to repeated measure variance, the mean scores of psychiatric symptoms (Depression, Anxiety, Aggression, Interpersonal sensitivity) in the PMS group were significantly higher than the healthy group (p< 0/05), and increase in severity of PMS from mild to severe was accompanied by increase in mean score of these subscales. There was a significant difference in mean score of depression, anxiety, aggression and interpersonal sensitivity between the 3rd and the 13th day of the cycle. Significant effect of the DSR grouping (PMS and Healthy group) and time interaction emerged in interpersonal sensitivity and aggression, significant effect on the DSR grouping (Mild, Moderate, Severer) and time interaction demonstrated in interpersonal sensitivity. Conclusion: Patients with prospective confirmed PMDD seemed to suffer from psychiatric symptoms. Therefore, recognizing co-morbid psychiatric symptoms in patients with PMDD is of prime importance. All healthcare providers should be sensitive to mental status of women with PMS. https://ijps.tums.ac.ir/index.php/ijps/article/view/225 https://ijps.tums.ac.ir/index.php/ijps/article/download/225/221