Piloting single session interventions for the early intervention of eating disorders

The 9 Single Session Interventions (SSIs) developed for this study were based on the top transdiagnostic targets deemed essential for the early intervention of eating disorder treatment by key stakeholders (people with lived experience N=38; significant others N=27; clinicians N=44; and researchers N=29) in a Delphi study (Pennesi et al., 2024). We also include an existing SSI by our team focused on behavioural activation to target low mood and motivation. Each of the 9 SSIs will be placed on a smartphone application, “NourishED Mind” and participants will only be given access to the one SSI they have been randomly assigned. Each SSI follows the B.E.S.T. elements of SSIs by Schleider et al. (2020). These are: “B: Brain science to normalize concepts in the program; E: Empower youths to a “helper” or “expert” role; S: Saying-is-believing exercises to solidify learning; T: Testimonials and evidence from valued others” (Schleider et al., 2020, p. 268). Each SSI will contain a ‘Learn’ section with psychoeducation and a ‘Do’ section containing interactive activities. All SSIs will include psychoeducation on functional nutrition and goals focused on increasing complex carbohydrate intake to support this. SSI content is evidence-based, drawing upon approaches such as Cognitive Behavioural Therapy (CBT: Beck, 1979), Acceptance and Commitment Therapy (ACT: Hayes et al., 2011), self-compassion (Neff, 2011), and Dialectical Behaviour Therapy (DBT: Linehan, 2015), and eating disorder specific approaches including CBT for eating disorders (CBT-E: Fairburn, 2008; Waller et al., 2007) and the Maudsley Model of Anorexia Nervosa Treatment for Adults (MANTRA: Schmidt et al., 2012). Each SSI is designed to be brief, between 20 to 40 minutes on one occasion, to sustain young peoples’ attention. The 9 SSIs cover the following topics: (1) Basing self-worth on just one or two limited areas; (2) Difficulty coping with developmental life transitions and change; (3) Distress tolerance and emotion regulation skills; (4) Low mood and motivation; (5) Low self-worth and self-acceptance; (6) Negative body image; (7) Persistent excessively high standards; (8) Self-criticism and low self-compassion; (9) Social media use. SSI adherence will be measured by assessing participants' time spent on the app NourishED Mind. Push notifications will be sent within the NourishED Mind app to promote completion of the SSIs and researchers will send email and text message reminders to aid participant retention and data collection.