Persistence of embitterment symptoms after the remission of major depressive disorder: outcomes of a 1-year follow-up

초록

Background: Major depressive disorder (MDD) and post-traumatic embitterment disorder (PTED) are highly comorbid psychiatric disorders. However, the mechanism by which psychiatric disorders affect each other’s course is unknown. Thus, this study aimed to investigate how PTED symptoms in remitted MDD patients change over a 1-year period. Methods: We designed a prospective, observational study with varying follow-ups over a 1-year period in a naturalistic setting of the psychiatric outpatient unit. In total, 317 patients who achieved remission of major depressive episode (MDE) were analyzed, where a PHQ-9 < 10 was defined as remission of MDE. All patients were given treatment as usual for MDE. Embitterment symptoms were collected using a PTED self-rating scale. At each visit, data using the PHQ-9, PHQ-15, and the PTED self-rating scale were collected. For all collected data, a paired t-test was conducted to analyze the changes of mean scores between baseline and each visit time. Results: Remitted MDE patients had significant embitterment symptoms. In post hoc analysis,anger and revenge symptoms did not improve during the all observational period. Physiological symptoms and post-traumatic stress disorder-related symptoms were improved for a short duration and persisted afterward. Embitterment and unfair feelings showed delayed improvement in treatment. Rumination and avoidance were decreasing continuously. Conclusion: In remitted MDE patients, the overall symptoms of comorbid PTED decreased for a short while before persisting again. Each embitterment symptom progresses differently, and the symptoms associated with anger and revenge do not improve at all. Further research is needed to determine the mechanism by which these symptoms clinically affect MDE recurrence or relapse.