Undoing Self-Contempt in Borderline Personality Disorder: A Controlled Test of Change in Emotion Processing in Psychotherapy

Background: Emotion processing has been discussed as a mechanism of change in several forms of psychotherapy for a broad range of psychological disorders. The general conclusions of the field do not allow for a step-by-step granularity of relevant emotional experiences in clients. This is particularly important for personality disorders, especially borderline personality disorder (BPD). Using a controlled out-of-therapy assessment, we assume that the lessening of expressed self-contempt by clients gives way to proportionally more expressions of self-compassion and assertive anger after a brief psychiatric intervention. Methods: The present secondary analysis of a randomized controlled trial includes N = 79 participants (n = 27 clients with BPD in the active treatment following the principles of good psychiatric management [GPM]; n = 23 clients with BPD in the treatment as usual [TAU]; n = 29 healthy controls). Both treatments—GPM and TAU—lasted 4 months. All participants underwent out-of-therapy experiential two-chair dialogues focusing on self-criticism at two time points. The participants' emotional expressions were assessed using the video-rated Classification of Affective Meaning States and the Self-Contempt Rating Scale. Results: The results indicated that the intensity of out-of-session observed self-contempt as part of a person-relevant self-criticism decreased in clients with BPD undergoing GPM, with a large effect, similar to healthy controls. A medium-sized effect was found for reduction in self-contempt in clients undergoing TAU. The results also indicated that the proportion of individuals with BPD undergoing GPM accessing self-compassion and assertive anger increased, which was not the case for healthy controls nor clients in TAU. Conclusions: Undoing self-contempt may be an elusive, yet central task in psychotherapy for clients with BPD. The present study explored the client process of change of undoing self-contempt and moving towards self-compassion and assertive anger. These conclusions bear important clinical and research implications. © 2026 The Author(s). Clinical Psychology & Psychotherapy published by John Wiley & Sons Ltd.