"It's like a car that doesn't like gasoline" - a qualitative study of siblings' understanding of anorexia nervosa in childhood: perspectives from siblings and parents.

BACKGROUND: When adolescents develop anorexia nervosa (AN), this impacts the family system and puts healthy siblings at risk of mental health problems. Siblings need support and age-appropriate information about the diagnosis to prevent negative mental health outcomes. However, evidence-based support for siblings is limited. The current study aimed to explore siblings' perceptions of AN and parents' beliefs about siblings' understanding expressed within an intervention programme for siblings and parents. METHODS: This qualitative study employed a hybrid approach, integrating deductive thematic analysis using the common sense model of self-regulation as a coding framework with inductive thematic analysis. The data materials comprised (1) interviews conducted by clinicians with siblings about the AN diagnosis, (2) siblings' understanding of AN as expressed in sibling groups, (3) parents' beliefs about what siblings understand expressed in parent groups, and (4) parent-sibling conversations about AN. Video and audio recordings of the data were transcribed and analysed. The sample comprised nine siblings of European descent, aged 8 to 15 years, and their parents. All siblings had a sister with clinically confirmed AN. RESULTS: The siblings had limited knowledge and expressed uncertainties about AN across the five themes identity (label and symptoms), causes, consequences, treatment, and timeline. In the inductive analysis, two additional themes were identified. The first, Parental perspectives on siblings' understanding, had two sub-themes: AN as a confusing and complex disorder, and Discrepancy between siblings' understanding of AN and parents' beliefs about their understanding. The second theme was Barriers to communication about the diagnosis. CONCLUSIONS: The results extend knowledge about informational support needs in siblings of adolescents with AN. Insights into what siblings and parents of adolescents with AN share about the diagnosis in different contexts can be used to guide the adaptation of interventions and policies. TRIAL REGISTRATION: ClinicalTrials.gov NCT04056884.