Predictors and Mediators of Outcome of a Focussed, Programme Led Intervention for Young People With Eating Disorders.

Background: Focussed and programme-led interventions have been of increased interest in the eating disorders (EDs) field as a potential solution to barriers in accessing timely, effective treatments. Little is known about the mechanisms through which these treatments work or for whom they are most suitable.

Objective: To identify mediators and predictors of outcome in a focused, program-led intervention for young people with EDs.

Method: Participants included young people with an ED (n = 169, female = 92.9%, M_age = 14.46 years) and their parents/caregivers (female = 147, male = 92), who undertook a 6-week parent-focused, psychoeducation-based treatment program and completed measures pre and post treatment. Young person measures included BMI centile, self-report measures of dietary restraint, ED-related obsessions and rituals, and expressed emotion (perceived criticism), and parents completed measures of self-efficacy.

Results: Overall, the models explained modest variance in outcomes. Results showed that increased parental self-efficacy mediated the effect of the treatment on reductions to dietary restraint, but not for BMI centile. Perceived criticism predicted the effect of the treatment on BMI centile, such that higher levels of perceived criticism were associated with less weight gain. ED-related obsessions and rituals predicted the effect of the treatment on dietary restraint, although the high correlation between these measures may limit the meaningfulness of this result.

Discussion: The findings support existing research in traditional treatments highlighting the benefits of empowering parental self-efficacy to progress ED recovery; it highlights the need for supporting families with high expressed emotion.