Diploma Thesis Title: The role of stress, depression and anxiety in temporomandibular disorders Objective:The main aim of this study was to determine a relationship between psychological distress such as stress, anxiety and depression and temporomandibular disorders (TMD). Beyond this, the goal was to discover correlation between psychological factors and pain symptoms in TMD. Material and Methods: In the period from March to August 2019, a cross-sectional survey was conducted at the University of Split School of Medicine. 75 individuals with TMD participated in the study. Questionnaires based study was conducted using the Depression, Anxiety, Stress Scale (DASS-42) for assessing the severity of depression, anxiety and stress among participants. Furthermore, the dentist indicated on the questionnaires whether pain was present or not. Results: Although 41% of the participants showed an increased level of depression, stress and /or anxiety, no association with TMD was observed. The mean values of the DASS questionnaire were within the normal range suggested by Lovibond and Lovibond (1995). There was no statistically significant correlation between psychological distress and pain symptoms in temporomandibular disorders. There was statistically significant moderate and strong correlation between the presence of symptoms of stress and anxiety and depression and anxiety, while the correlation between depression and stress symptoms was relatively weak. Conclusion: In conclusion, our results did not show influence of psychological distress such as stress, anxiety and depression on TMD. Although numerous studies showed an association between negative emotional states and temporomandibular disorders, there is still a problem in trying to decide whether these psychological states have caused the functional problems, or are caused by TMD, or if any relationship exists at all. New insights can help in the development of new and effective treatments and also in diagnosis of TMD.