(PS14-23) Trajectories of Therapeutic Skills Use and Their Dynamic Relations to Symptom Change During Cognitive-behavioral Therapy for Bulimia Nervosa

The leading treatment for bulimia nervosa (BN) is cognitive-behavioral therapy (CBT), a skills-oriented treatment aimed at modifying disordered behaviors and cognitions related to eating, shape, and weight. Yet, a significant proportion of patients who receive CBT have suboptimal outcomes. Thus, research is needed to investigate factors that drive symptom improvement during CBT, which could inform treatments that target the most potent mechanisms of change. This study leveraged digital self-monitoring to examine trajectories of CBT skills use and weekly relations between skills use and symptom change during a course of CBT for BN.

Fifty-five adults (M age: 39.0 ± 14.1; 83.9% female; 64.3% White, 93.6% non-Hispanic/Latino) receiving CBT for BN-spectrum eating disorders (EDs) self-monitored their use of five therapeutic skills (i.e., regular eating, eating enough to prevent excessive hunger and eating a range of macronutrients, breaking dietary rules, urge management strategies, and mood management strategies) via a smartphone app several times per day during 16 weeks of treatment. Patients also self-reported their ED symptoms (i.e., frequency of binge eating, compensatory weight control behaviors, and dietary restraint) weekly. Linear mixed-effects models were used to examine trajectories of CBT skills use during treatment and to test whether skills use one week was associated with reduced or stabilized symptoms the same week and the following week.

Participants showed significant increases in eating enough to prevent excessive hunger and eating a range of macronutrients from week-to-week (ps < .05). Regular eating, eating enough to prevent excessive hunger, and eating a range of macronutrients one week predicted lower binge eating and compensatory behaviors the same week and the following week, and urge management strategy use predicted greater binge eating the same week and the following week (ps < .05). Breaking food rules and use of mood management strategies were not associated with ED symptoms.

Results showed temporal relationships between therapeutic skills use and symptom change on a weekly level, with evidence that using skills targeting dietary restraint (i.e., regular eating, eating enough to prevent excessive hunger and eating a range of macronutrients) was associated with lower BN symptoms. An important future direction is to compare the relative strength of the effects of specific skills on symptoms to identify the most potent “active ingredients” in CBT. However, research is first needed to improve methods of momentary assessment in this area with the use of digital technology.