Are within- and between-session changes in distress associated with treatment outcomes? Findings from two clinical trials of exposure for eating disorders.

ABSTRACT

OBJECTIVE: Imaginal exposure is a novel intervention for eating disorders (EDs) that has been investigated as a method for targeting ED symptoms and fears. Research is needed to understand mechanisms of change during imaginal exposure for EDs, including whether within- and between-session distress reduction is related to treatment outcomes. METHOD: Study 1 tested four sessions of online imaginal exposure (N = 143). Study 2 examined combined imaginal and in vivo exposure, comprising six imaginal exposure sessions (N = 26). ED symptoms and fears were assessed pre- and posttreatment, and subjective distress and state anxiety were collected during sessions. RESULTS: Subjective distress tended to increase within-session in both studies, and within-session reduction was not associated with change in ED symptoms or fears. In Study 1, between-session reduction of distress and state anxiety was associated with greater decreases in ED symptoms and fears pre-to posttreatment. In Study 2, between-session distress reduction occurred but was not related to outcomes. CONCLUSIONS: Within-session distress reduction may not promote change during exposure for EDs, whereas between-session distress reduction may be associated with better treatment outcomes. These findings corroborate research on distress reduction during exposure for anxiety disorders. Clinicians might consider approaches to exposure-based treatment that focus on distress tolerance and promote between-session distress reduction.