Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 7 4 2021 02 21 213 221 Shamsoulmolouk Najafi Dental Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Oral & Maxillofacial Medicine, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran; Department of Oral & Maxillofacial Medicine, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran. Zahra Faraji School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. 2020 11 07 2021 02 20 Introduction: The etiology of TMD is complex and multifactorial, but it is thought that psychological factors contribute to the etiology and persistence of TMD. Therefore, the aim of this study was to investigate the role of anxiety and depression in the development of temporomandibular joint disorders in patients referred to Tehran University of Medical Sciences, School of Dentistry, International Campus. Materials and Methods: This cross-sectional study was performed on patients referred to Tehran University of Medical Sciences, School of Dentistry, International Campus who had temporomandibular joint disorder. Hence the number of 224 people easily selected at random. They were given 3 questionnaires to assess their anxiety and depression (9-PHQ, 4-PHQ7 and-GAD-7). After collecting data using SPSS software version 22 and considering the error level at 0.50% probability and one-way analysis of variance and frequency analysis were performed. Results: The rate of depression in patients with TMD was 8.83 according to the 9-PHQ questionnaire and 4.72 according to the 4-PHQ questionnaire, and the level of anxiety in patients with TMD according to the 7-GAD questionnaire was equal to 8.95 There was no significant relationship between patients’ gender and their level of anxiety (p<0.50), but there was a significant relationship between patients’ age and their level of anxiety (p>0.50). Conclusion: Age and gender are not significantly associated with temporomandibular joint disorders.  Also, anxiety and depression are positively related and there is a significant value achieved with the incidence of TMD in the participants. A reduction in the level of anxiety and depression within people, can have a great impact on the treatment of TMDs in individuals. Keywords: Temporomandibular joint disorder; Anxiety; Depression. https://jcr.tums.ac.ir/index.php/jcr/article/view/352 https://jcr.tums.ac.ir/index.php/jcr/article/download/352/311