Acceptance and compassion-based therapy targeting shame in body dysmorphic disorder

<jats:p>&lt;p dir="ltr"&gt;Background: Body dysmorphic disorder (BDD) is a severe and often persistent psychiatric disorder associated with substantial distress, functional impairment, and reduced quality of life. Although effective treatments are available, many individuals do not receive treatment or continue to experience clinically significant symptoms. Shame is considered a central process in BDD and may contribute to the maintenance of the disorder and interfere with treatment engagement, but interventions targeting shame have received limited empirical attention.&lt;/p&gt;&lt;p dir="ltr"&gt;Aims: The overall aim of this thesis was to advance the understanding and treatment of BDD by developing and evaluating acceptance- and compassion-based interventions targeting shame and by improving the assessment of body-related shame and guilt. Specifically, the thesis aimed to (i) evaluate an ACT-based exposure treatment for BDD, (ii) develop and examine an acceptance- and compassion-based intervention targeting shame, and (iii) develop and evaluate the psychometric properties of the Body Shame and Guilt Scale (BSGS).&lt;/p&gt;&lt;p dir="ltr"&gt;Methods: Study I was an open pilot study in which 21 psychiatric outpatients with BDD received a 12-week ACT-based exposure treatment. Study II used a randomized nonconcurrent multiple-baseline design to evaluate a 12-session acceptance- and compassion-based intervention targeting shame in five treatment completers with BDD. Study III developed and evaluated the BSGS in a sample of 832 adults reporting dissatisfaction with their appearance using bifactor analysis and Rasch modeling.&lt;/p&gt;&lt;p dir="ltr"&gt;Results: In Study I, 19 of 21 participants completed treatment. BDD symptom severity decreased significantly from pre- to post-treatment, with a large within-group effect size, and improvements were also observed in depressive symptoms, disability, quality of life, and psychological inflexibility. Treatment gains in BDD symptoms were maintained at six-month follow-up. In Study II, the intervention was associated with reductions in BDD-related behaviors, self-criticism, shame, depressive symptoms, and overall BDD symptom severity for most participants, as well as improvements in quality of life, self-compassion, and psychological flexibility. Participants generally rated the treatment as credible and acceptable. In Study III, the final BSGS comprised separate 10-item body shame and body guilt scales. Both scales demonstrated satisfactory dimensionality, reliability, and found no evidence of problematic differential item functioning across age, gender or BDD screening status.&lt;/p&gt;&lt;p dir="ltr"&gt;Conclusions: This thesis provides preliminary support for the feasibility and potential benefit of acceptance- and compassion-based treatment for BDD and introduces the BSGS as a promising brief measure of body-related shame and guilt. Together, the findings support further investigation of shame as a clinically meaningful process and treatment target in BDD. Further validation of the BSGS in clinically diagnosed and longitudinal samples, together with larger randomized controlled trials evaluating the efficacy and mechanisms of acceptance- and compassion-based treatment, is warranted.&lt;/p&gt;&lt;h3 dir="ltr"&gt;List of scientific papers&lt;/h3&gt;&lt;p dir="ltr"&gt;I. &lt;b&gt;Linde, J.&lt;/b&gt;, Rück, C., Bjureberg, J., Ivanov, V. Z., Djurfeldt, D. R., &amp; Ramnero, J. (2015). Acceptance-Based Exposure Therapy for Body Dysmorphic Disorder: A Pilot Study. Behavior Therapy, 46(4), 423- 431. &lt;a href="https://doi.org/10.1016/j.beth.2015.05.002"&gt;https://doi.org/10.1016/j.beth.2015.05.002&lt;/a&gt;&lt;/p&gt;&lt;p dir="ltr"&gt;II. &lt;b&gt;Linde, J.&lt;/b&gt;, Luoma, J. B., Rück, C., Ramnerö, J., &amp; Lundgren, T. (2023). Acceptance and Compassion-Based Therapy Targeting Shame in Body Dysmorphic Disorder: A Multiple Baseline Study. Behavior Modification, 47(3), 693-718. &lt;a href="https://doi.org/10.1177/01454455221129989" target="_blank" rel="noreferrer"&gt;https://doi.org/10.1177/01454455221129989&lt;/a&gt;&lt;/p&gt;&lt;p dir="ltr"&gt;III. &lt;b&gt;Linde, J.&lt;/b&gt;, Åhlén, J., Luoma, J. B., Rück, C., &amp; Lundgren, T. Development and Initial Psychometric Evaluation of the Body Shame and Guilt Scale. [Manuscript]&lt;/p&gt;</jats:p>