Moderators of weight gain in the early stages of outpatient cognitive behavioral therapy for adults with anorexia nervosa: Replication and extension

Objective: This study extends previous work, examining psychological factors that influence the level of weight gain across the first 20 sessions of cognitive behavioral therapy (CBT) for anorexia nervosa.

Method: Thirty-two patients with anorexia nervosa (mean body mass index (BMI) = 16.0; SD = 1.11) completed measures of eating attitudes and comorbid axis 1 pathology at the outset of CBT, and their weight gain was measured at the 6th and 20th sessions of the therapy.

Results: Unhealthy eating attitudes at the start of therapy were associated with slower weight gain across the first 20 sessions of CBT. In contrast, higher levels of pretreatment axis 1 pathology were associated with slower weight gain only after the 6th session. The axis 1 features that moderated weight gain over 20 sessions of CBT were broader than those that had previously been shown to predict weight gain over the first 10 CBT sessions.

Discussion: During CBT for anorexia nervosa, weight gain might be enhanced by addressing a range of aspects of axis 1 pathology (e.g., depression, hostility, and features of anxiety). However, the approach is likely to be less important at first than directly addressing eating pathology and overvalued ideas about eating, shape, and weight.