Course and outcome in individuals with atypical anorexia nervosa: Findings from the Study of Refeeding to Optimize iNpatient Gains (StRONG)

ObjectiveWe previously reported that participants with atypical anorexia nervosa (atypical AN) had higher historical and admission weights, greater eating disorder psychopathology, but similar rates of amenorrhea and weight suppression at baseline as compared to anorexia nervosa (AN); here, we compare 1-year outcomes. MethodWeight, % median body mass index (%mBMI), Eating Disorder Examination Questionnaire (EDE-Q) scores, resumption of menses, and rehospitalizations were examined at 3, 6, and 12 months post-discharge. Analyses (N = 111) compared changes in %mBMI, weight suppression, and EDE-Q scores over time between atypical AN and AN. ResultsAmong the participants (48 atypical AN, 63 AN), both groups gained weight but those with atypical AN had lower gains than those with AN in %mBMI (p = .02) and greater weight suppression (p = .002) over time. EDE-Q scores improved over time, independent of weight suppression, with no significant difference between atypical AN and AN. Groups did not differ by rates of resumption of menses (80% atypical AN, 76.9% AN) or rehospitalization (29.2% atypical AN, 37.9% AN). Greater weight suppression predicted longer time to restore menses and more days of rehospitalization. DiscussionIndividuals with atypical AN regained a smaller proportion of body mass and were more weight suppressed over time. Change in eating disorder cognitions, resumption of menses, and rehospitalization rates at 1-year follow-up did not differ between groups. There was no significant difference in weight suppression between groups for those who were psychologically improved at 12 months. Findings highlight limitations in our understanding of weight recovery in atypical AN. New metrics for recovery are urgently needed. Public SignificanceLittle is known about outcome in atypical anorexia nervosa (atypical AN). We examined recovery metrics in young people with atypical AN and anorexia nervosa (AN) 1 year after medical hospitalization. Individuals with atypical AN showed slower weight gain and remained further from their pre-illness weight. There were no differences in the rates of psychological recovery, resumption of menses, or rehospitalization. New metrics are needed to assess recovery in atypical AN.