Social Anxiety and Peer Relationships Predict Weight Recovery in Adolescent Onset Anorexia Nervosa

Adolescence is period of social change during which peer relationships are prioritised. The desire for social approval, which heavily influences behaviour, is often linked to an increased risk of developing an eating disorder (ED). Social cognition is impaired in ED and both autism and social anxiety frequently co-occur. It is difficult to disentangle the contributing factors of cognitive and interpersonal difficulties in adolescents who present at children's ED services, and whether these relate to treatment response. We investigated whether baseline social measures predicted early treatment response after the initial 6-month period.

Adolescents aged 12-16 years (N = 983) treated by children's community ED services in England, UK, between 2017 and 2023, completed the Revised Child Anxiety and Depression Scales (RCADS) and/or the Strengths and Difficulties Questionnaire (SDQ) at assessment. Early weight restoration, defined as reaching at least 85% median-BMI adjusted for age and sex, at 6 months, was the primary outcome. A multiple linear regression was conducted using three measures: RCADS' Social Phobia, SDQ's Peer Problems and SDQ's Prosocial Behaviour to predict the degree of early weight restoration (85%medBMI), which was the primary outcome.

The combined baseline social predictors: social phobia (standardised β = -0.382), peer problems (standardised β = -0.118) and prosocial behaviour (standardised β = -0.105) explained 20% of variance in weight restoration at 6-months post assessment (p < 0.001). Individual predictors regressed to %mBMI, were not moderated by age, with peer problems negatively predicting weight at 6 months and prosociality scores demonstrating significant skew because self-rated scores were high. Exploratory analyses showed that social anxiety was greater in those who did not reach early weight recovery at 6-months post assessment.

Assessing and addressing difficulties in social/peer group functioning might be a central consideration in treatment for AN in adolescents. Further research is needed to better understand the role of social functioning in recovery from AN.