1 - (SYM 1) Rewiring Reward: Positive Affect Treatment as a Novel Approach for Anorexia Nervosa and Associated Comorbidities

Introduction: A significant body of research has found that anorexia nervosa (AN) is associated with reward processing dysfunctions paralleling those identified in affective disorders, including deficits in reward anticipation, experiencing, and learning. These reward dysfunctions may account for the high comorbidity between AN and mood and anxiety disorders, which predict poorer treatment outcomes in this population. Additionally, unlike individuals with affective disorders, individuals with AN also demonstrate elevated reward responsivity to eating disorder-relevant stimuli (e.g., thinness cues), which may maintain eating disorder symptoms. Despite the relevance of reward targets to the symptom expression of AN, few AN treatments directly target these processes or comorbid mood and anxiety disorders, which may limit long-term clinical improvement. 

Method: To address this gap in the literature, we adapted Positive Affect Treatment, a neuroscience-informed behavioral treatment developed for affective disorders, to the treatment of AN (PAT-AN). In this presentation, we will share the results of our pilot study, wherein adults with AN (N = 20) were randomized to 20 weeks of PAT-AN or waitlist to investigate the feasibility, acceptability, preliminary efficacy, and target engagement of PAT-AN.

Results: PAT-AN demonstrated strong retention (100%) and high acceptability ratings (M = 5.67-5.95 on a 7-point scale). BMI (p = .006) and eating disorder symptoms (p < .001) improved over PAT-AN sessions and the PAT-AN group showed medium to large pre-to-post-treatment improvements in BMI, eating disorder symptoms and impairment, and depressive and anxiety symptoms. Some moderate change was noted on certain reward indices (e.g., social anhedonia), however these results were not consistent. Most changes were sustained at 3-month follow-up. In contrast, waitlist showed negligible changes (ds < .20) on nearly all measures. However, waitlist participants subsequently enrolled in PAT-AN showed comparable change to those originally assigned to this treatment. Qualitative feedback suggested that the strengths-based approach may have contributed to PAT-AN outcomes.



Discussion: Results of our pilot study suggest that PAT-AN holds promise as an innovative treatment with capability to simultaneously improve eating disorder symptoms, affective symptoms, and underlying reward mechanisms. We will discuss an ongoing larger-scale clinical trial aiming to further investigate the efficacy and target engagement in PAT-AN.