Comorbid Depression in Hospitalised Youth With Anorexia Nervosa: Characteristics, Correlates, and Impact on Weight Gain and Treatment Duration

ABSTRACT Objective Anorexia nervosa (AN) is associated with high rates of comorbidities. The impact of comorbid depression‐spectrum disorders (DSDs) in AN patients on the outcomes of inpatient treatment is insufficiently studied. Method Retrospective study of youth with AN (9–18 years), admission weight < 10th body mass index (BMI) percentile, consecutively hospitalised in a child and adolescent psychiatry university department. Patients with AN+DSD as the only psychiatric comorbidity were compared with AN patients without psychiatric comorbidity (ANnoComorbidity). Results Among 220 female AN inpatients (median = 15.0 years) 62 had AN+DSD versus 158 had ANnoComorbidity. Patients with AN+DSD were more likely to report childhood emotional abuse ( p = 0.020), and to receive psychotropic medications (any: p < 0.001; antidepressants: p < 0.001; antipsychotics: p = 0.001). Moreover, AN+DSD had less average weekly weight gain ( p = 0.012) and longer inpatient treatment ( p < 0.001). Independent correlates of less average weekly weight gain included lower admission BMI z ‐score ( p < 0.001), antipsychotic ( p = 0.002) and antidepressant ( p = 0.004) treatment ( R 2 = 0.17, p < 0.001). Independent correlates of longer hospitalisation included lower admission BMI z ‐scores ( p < 0.001), antipsychotic ( p < 0.001) or antidepressant ( p < 0.001) treatment ( R 2 = 0.27, p < 0.001). Conclusion AN+DSD were hospitalised longer and gained less average weight/week compared to ANnoComorbidity. Lower admission weight, antipsychotic or antidepressant co‐treatment were independently associated with less average weight gain and longer inpatient stays.