Patterns of Symptom Change in Behaviors and Cognitions During 10-Session Cognitive Behavioral Therapy (CBT-T) for Non-Underweight Eating Disorders.

Objective: Little is known about the timing of behavioral versus cognitive change in 10-session cognitive-behavioral therapy for non-underweight eating disorders (CBT-T). We aimed to: (a) evaluate the magnitude of behavioral and cognitive symptom reduction across treatment; and (b) investigate the relation between early behavioral change and subsequent cognitive change. We hypothesized: (a) large and significant reductions in behavioral and cognitive symptoms from pre- to mid-treatment and from pre- to post-treatment; and (b) that early behavioral change would predict subsequent cognitive change over the course of treatment.

Method: Patients (N = 63) were offered CBT-T and completed the Eating Disorder-15 on a weekly basis. We used intent-to-treat analyses. For Aim 1, we conducted a series of fixed-effect multilevel models for each outcome variable, accounting for repeated measures (pre-, mid-, and post-treatment) within individuals. For Aim 2, we conducted a linear regression using early behavioral change as the predictor and subsequent cognitive change as the outcome.

Results: We observed large and significant reductions in most behavioral and all cognitive symptoms pre- to mid-treatment and pre- to post-treatment. Early changes in behavioral symptoms did not significantly predict subsequent cognitive changes.

Discussion: Behavioral improvements occurred rapidly and were sustained throughout treatment, whereas cognitive changes followed a more gradual trajectory. The absence of a significant predictive relationship between early behavioral change and subsequent cognitive change suggests that these domains may improve independently. Future research should investigate the mechanisms linking behavioral and cognitive changes.