Trajectories of interpersonal problems in residential eating disorder treatment: Exploring the influence of primary diagnosis.

Baseline interpersonal problems have been associated with treatment outcome in eating disorders (ED) and are important for understanding ED maintenance and aetiology. Despite this evidence, little is known about trajectories of change in interpersonal problems in the context of treatment, particularly in intensive ED treatment. This study examined the trajectory of total interpersonal problems in residential ED treatment, as well as two subdomains previously highlighted in ED research of being overly Cold (interpersonally distant) or overly Domineering (interpersonally controlling), as a function of different primary presenting ED diagnoses: anorexia nervosa restricting subtype (AN-R), binge-purge subtype (AN-BP), and bulimia nervosa or binge eating (BN/BED). Interpersonal problem data were collected at admission, discharge, and 6-month follow-up. Trajectories were analysed with multilevel models. Results showed small-to-medium statistically significant reductions in interpersonal problems across diagnostic groups from admission to discharge for total interpersonal scores, and gains appeared to be maintained at follow-up for both AN groups. Patients diagnosed with primary AN experienced steeper declines in total interpersonal problems from admission to follow-up compared with patients diagnosed with BN/BED, with AN-R experiencing the steepest trajectory. Planned contrasts indicated anyone with relevant binge eating behaviours had higher average levels of both Cold, as well as Domineering problems. Exploratory contrasts suggested that patients who had more Domineering problems also exhibited more binge symptoms and were typically slower to improve. Overall, results suggest interpersonal problems are generally malleable in residential ED treatment, yet change patterns differ by presenting ED symptoms and interpersonal problem subdomain.