Eating Disorder Features in Bipolar Disorder: Course, Psychological Correlates, and Relationship with Quality of Life

Abstract

Despite growing interest in eating disorders (EDs) comorbid with bipolar disorder (BD), little research has considered the nature of ED features and their association with physical health and psychosocial outcomes. The current research aimed to assess ED features in people with BD and their association with BMI and psychological factors. People with BD (Aus=73, Netherlands=109) completed online questionnaires and 9 Australian participants with the comorbidity participated in a qualitative interview. In total, 31 (19%) were identified as having a probable ED, most commonly binge eating disorder (45%). Only one reported a formally-diagnosed ED. Comorbid EDs were associated with significantly poorer emotion regulation ability, reduced quality of life (QoL), and higher distress, but not impulsivity. Greater depressive symptoms and more frequent hospital admissions for depression were also reported. The most common ED features were weight/shape overvaluation (36%) and objective binge eating episodes (OBEs; 21%). OBEs and restriction uniquely contributed to poorer QoL in a regression model. Positive beliefs about the function of binge eating, but not OBEs, predicted higher body mass index (BMI). Interviews revealed that BD illness episodes often correlated with changes in eating and BMI. Most participants connected their experience of an ED and BD to traumatic experiences. None felt that concerns with their eating, weight gain and physical health had been adequately addressed. Results suggest that this double diagnosis and even subthreshold EDs in BD are associated with elevated ED cognitions and heightened difficulties with emotion regulation. Clinicians and researchers alike should consider more proactive screening for this comorbidity as a significant contributing factor to disability. Future interventions for this under-supported group could consider targeting cognitive processes, emotion regulation difficulties and comorbid traumatic stress disorders.