Family-based Therapy for Anorexia Nervosa – How should treatment be adapted to meet the needs of autistic adolescents?

Background Anorexia Nervosa (AN) is an eating disorder associated with a high risk of physical complications and mental health comorbidity. Having AN significantly increases the chances that someone will die prematurely. A disproportionate number of people presenting with AN are autistic, with autism being prevalent in 1% of the general population and 15-30% of people accessing treatment for AN. Adolescents with AN have poorer treatment outcomes and are more likely to require lengthy inpatient admissions if they are autistic. Family-based Therapy for AN (FT-AN) is an effective psychological intervention for adolescents with AN that is recommended by NICE guidelines. However, there is evidence that it is less effective for a large proportion of autistic adolescents. Currently, research is lacking on when and why FT-AN is effective for some autistic adolescents and not others. Filling this knowledge gap will inform understanding of how FT-AN needs to be changed to provide more effective care for autistic young people. Aim To develop a clearer understanding of when and why FT-AN is effective for autistic adolescents and their families and when and why it is ineffective or harmful. Methods A realist review of relevant literature to develop and refine a programme theory that explains when and why FT-AN is effective and ineffective for autistic adolescents. A Delphi study with eating disorder clinicians who have experience with AN and autism to generate consensus on the key barriers and facilitators to the acceptability and effectiveness of FT-AN for autistic adolescents and their parents. Expert consensus will also be sought on identifying how to adapt FT-AN and on the autism-relevant training needs of practitioners. A qualitative study to explore how autistic adolescents with AN and their parents understand the helpful and unhelpful factors and processes of FT-AN. To compare these with the experiences of non-autistic adolescents with AN and their parents to identify possible factors that are distinctive to autistic people. The findings from parts 1-3 will be discussed in a set of PPI workshops to co-produce a set of guidelines on how to either adapt FT-AN so it works better for autistic people or provide recommendations to support the development of a new treatment. Anticipated impact and dissemination The research will be shared via publications in high-impact journals and presentations at conferences. Findings will also be distributed nationally and internationally via training delivered by a national and specialist eating disorder service. The research will inform funding applications to co-produce an adapted or novel intervention based on the DCAF research findings, followed by a feasibility trial. Timelines for delivery The research programme will be completed over three years. Studies 1 and 2 will be completed in Years 1-2 and Study 3 will be completed in Year 2. The co-production meetings to summarise the findings will take place in the first half of Year 3. The final six months will focus on dissemination, writing up the PhD thesis, and writing a funding application for the next phase.