4 - (SYM 126) Different Assessments of Cognitive Flexibility Uniquely Predict Eating Disorder Treatment Outcomes in Adolescent Bulimia Nervosa

Objective: Cognitive rigidity, or difficulty adapting to new or changing demands, is hypothesized to be an endophenotype of anorexia nervosa. Similar to anorexia nervosa, bulimia nervosa (BN) is characterized by stereotyped behaviors that may be exacerbated by cognitive rigidity (e.g., dietary rules, binge-purge cycles, treatment non-response). However, less is known about the relation between cognitive flexibility (CF) and BN symptoms, particularly in adolescence when onset is most common. Clarifying this relation and best assessment practices may guide informed clinical decision-making with respect to case formulations, auxiliary interventions, and assessment choice. To accomplish this, the current study compared how two measures of CF (i.e., Wisconsin Card Sort Task [WCST]; Trail Making Task [TMT]) relate to eating disorder symptoms in adolescents with BN.

Method: A subsample (n=78) of adolescents with BN from a treatment trial was analyzed. Linear and hurdle regressions were used to compare the effects of WCST perseverative errors and TMT performance on eating disorder severity (i.e., Eating Disorder Examination Global Score), objective binge episodes (OBEs), and self-induced vomiting episodes (SVEs) at baseline and end-of-treatment (EOT). All models controlled for treatment condition, duration of illness, and presence of comorbidities. EOT models also controlled for baseline severity.

Results: Neither the WCST or TMT associated with baseline BN symptoms. TMT performance positively associated with the likelihood of engaging in SVEs at EOT (𝛽=.47, p=.01, 95% CI [.11, .84]) and, among adolescents who endorsed ≥1 SVE at EOT, WCST perseverative errors (𝛽=.05, p=.005, 95% CI [.01, .08]) positively associated with SVE frequency at EOT.

Discussion: The overall lack of associations between CF and outcomes suggests that cognitive rigidity may not be as relevant to the clinical profile of adolescent BN as for anorexia nervosa. In the few significant associations that emerged, the WCST and TMT uniquely predicted severity of vomiting at EOT in this sample. If findings are replicable and/or CF emerges as a more consistent feature of adolescent BN in future work, then clinicians may use the WCST or TMT to collect unique information about SVE remission at EOT. For example, the TMT may be better equipped to answer questions related to treatment response; whereas the WCST may be more desirable for answering questions related to severity among non-responders.