Imagery-based Cognitive Therapy for Patients with Persistent Depressive Disorder: A Hermeneutic Single-Case Efficacy Design

Background: Persistent depression is a chronic and refractory disorder associated with many mental comorbidities. The effects of traditional cognitive therapy, which is the most common treatment for depression, have been negligible. Objectives: The aim of this study was to assess the effectiveness of imagery-based cognitive therapy in patients with persistent depressive disorder. Methods: The Hermeneutic Single-Case Efficacy Design (HSCED) was used in this study. This quantitative-qualitative method is an alternative to randomized controlled clinical trials and is used to assess the effectiveness of new therapies in a new group of patients. The case was a 30-year-old man who participated in 13 treatment sessions. The Beck Depression Inventory (BDI-II), Cornell Dysthymia Rating Scale (CDRS), Positive and Negative Affect Scale (PANAS), Rosenberg Self-esteem Scale (RSE), and Brief Core Schema Scales (BCSS) were used to collect quantitative data. Helpful Aspects of Therapy (HAT), the Change Interview (CI), and Therapist Session Notes Questionnaire (TSNQ) were used to gather qualitative data. The data were analyzed by the hermeneutic method and based on 56 criteria of Bohart. Results: Quantitative findings showed that depression symptoms, positive & negative self-beliefs, and positive & negative self-esteem had significant alterations. Regarding qualitative data and treatment efficacy, according to the 56 criteria of Bohart, there was at least 81% confidence denoting a change in the patient and 75% confidence relating this change to the treatment. Conclusion: The results indicated that the patient had a positive experience with imagery cognitive therapy that not only alleviated depression symptoms but also improved the lack of self-esteem, which is one of the important signs of persistent depression according to the DSM-5 criteria. However, because this method had no effects on positive & negative core beliefs about others, it is recommended to concomitantly use complementary methods such as Cognitive Behavioral System Analysis Psychotherapy (CBASP), which is a method used to improve interpersonal relationships.