Changes in insomnia and binge‐eating symptom severity before and after treatment of eating disorders in individuals with non‐low‐weight binge‐spectrum disorders

Although emerging research suggests insomnia is a significant problem among people with eating disorders, little is known about how insomnia symptoms may serve as risk factors for eating disorder symptoms, treatment outcome, and relapse. University students with non-low-weight eating disorders (N = 89) completed a mobile guided self-help cognitive behavioural intervention for eating disorders. Insomnia and binge-eating symptoms were assessed at pre-treatment and end-of-treatment using the Insomnia Severity Index and Eating Pathology Symptoms Inventory. Multiply imputed datasets were used to test associations between insomnia and binge eating before, during and after treatment. Insomnia was positively associated with binge-eating symptoms prior to treatment (r = 0.47). Baseline insomnia symptoms were associated with binge-eating symptoms at end-of-treatment (est = 0.269). Eating disorder treatment modestly reduced insomnia (d = -0.38); however, about half of people with clinically significant insomnia prior to treatment remained symptomatic. Insomnia symptoms and binge-eating symptoms did not change concurrently during treatment. Overall, results support an association between insomnia and binge eating. Although eating disorder treatment may impact insomnia, many individuals remained symptomatic for sleep problems, suggesting the need for follow-up treatments, such as cognitive behavioural therapy for insomnia, or the development of integrated insomnia-eating disorder treatments. Future studies are needed to examine causal links between insomnia and eating disorder symptoms, and test if insomnia predicts relapse after eating disorder treatment.