Heterogeneous weight restoration trajectories during partial hospitalization treatment for anorexia nervosa

Early response to treatment has been shown to predict good outcome in family-based treatment, but little is known about who responds quickly.

The purpose of the current study was to examine the short-term weight gain trajectories among youth receiving partial hospitalization program services for anorexia nervosa (AN), and to identify predictors of these trajectories.

Adolescent and young adults (n = 102) with AN or subthreshold AN completed semi-structured interviews and self-report measures on admission to a family-based partial hospitalization program. Patients participated in programming 5 days a week.

Three weight gain trajectories were found to indicate slow, moderate, and rapid weight gain trajectories. All rapid responders gained at least four lbs. in the first 4 weeks of treatment, compared to 86.1% of moderate responders and 51.2% of slow responders. Patients were less likely to have a moderate or rapid response trajectory if they had a mood disorder diagnosis and higher parental expressed emotion. Additionally, the presence of compensatory behavior increased the likelihood of having a rapid response.

Despite the sometimes chronic nature of AN, most patients fell into one of the two favorable response trajectories. The identification of these trajectories underscores the importance of considering the core disordered eating behaviors (i.e., restricting, binge eating, and purging), comorbid psychopathology, and parental expressed emotion.