Changes in and Remission of Body Weight and Eating Disorder Psychopathology in Adolescents with Anorexia Nervosa During and Four Weeks Post Inpatient Treatment.

OBJECTIVES

To assess associations between body weight metrics and eating disorder (ED)-psychopathology in adolescents with anorexia nervosa (AN) at baseline and four weeks post-discharge (4-week follow-up) from inpatient psychiatric multimodal treatment (IMT), calculating full and partial body mass index (BMI) percentile/ED-psychopathology remission rates.

METHODS

Secondary analysis of a prospective observational cohort study in adolescents (12-18 years) with AN-restricting (AN-R)/-binge-purge (AN-BP), and atypical AN (AAN). Body weight metrics and ED-psychopathology (Eating Disorder Examination Questionnaire, EDE-Q) were assessed at baseline and 4-week follow-up. Remission at 4-week follow-up was calculated by applying German-AN-S3-guidelines-based vs. DSM-5 criteria.

RESULTS

In 40 adolescents (mean age = 15.6 ± 1.5 years; females = 90%; BMI z-score = -2.59 ± 1.07) receiving IMT (median duration = 118 (IQR = 90-150) days), BMI z-score increased (-2.61 to -1.04, p < 0.001) and EDE-Q global score decreased (3.26 to 1.81, p < 0.001) from baseline to 4-week follow-up. Greater weight gain/week during IMT had a positive impact on ED-psychopathology at 4-week follow-up. In multivariable analyses, greater BMI z-score improvement was independently predicted by lower baseline BMI z-score (p < 0.001) and fewer baseline comorbid psychiatric diagnoses (p = 0.034) (R2Adjusted = 0.545). Greater EDE-Q global score improvement was independently predicted by typical vs. atypical AN (p = 0.005), higher baseline BMI z-score (p = 0.012), and higher baseline EDE-Q restraint (p = 0.048) (R2Adjusted = 0.376). By applying stricter S3-guideline-based vs. DSM-5 BMI percentile criteria, full BMI percentile/ED-psychopathology remission was lower (12.5% vs. 50.0%, p = 0.001), while non-remission was higher (25.0% vs. 5.0%, p = 0.001).

CONCLUSIONS

The complex relationships between body weight metrics, ED-psychopathology, and treatment outcome trajectories in AN, including treatment response and remission criteria, require further investigation.