Objective: Both of the defense mechanisms of ego and depression, affects the intensity of the pain in the patient with chronic pain. The present study investigates the mediating role of depression in the relationship between immature ego defenses and perceived pain intensity in patients with chronic pain. Method: Research was conducted on 503 patients with chronic pain who were referred to pain centers in Tehran. Participants were asked to answer Numerical Rating Scale (NRS) for perceived pain intensity, Defense Styles Questionnaire (DSQ-40), and Depression, Anxiety, and Stress Scale (DASS). Results: The results indicated that depression plays a mediating role in the relationship between immature ego defenses and perceived pain intensity in patients with chronic pain. Conclusion: the relationship between immature ego defenses and the perceived pain intensity is not a simple linear one, but is mediated by depression. So, depression has an important role in Transforming of defense mechanisms to the pain.
