Restrictive eating disorders among adolescent inpatients.

BACKGROUND AND OBJECTIVES: Clinicians are increasingly observing adolescents who have lost large amounts of weight, experience typical cognitions and acute medical complications of anorexia nervosa (AN), yet do not meet diagnostic criteria for AN owing to weight. We refer to this category of Eating Disorder Not Otherwise Specified as EDNOS-Wt. We set out to describe the changing incidence of EDNOS-Wt compared with AN, and to compare the characteristics of these 2 groups in a cohort that required hospitalization after weight loss.

METHODS: A 6-year retrospective cohort study (2005 to 2010) was undertaken of first admissions of 12- to 19-year-old patients to a tertiary children's hospital using Diagnostic Statistical Manual of Mental Disorders, Fourth Edition (DSM IV) AN or EDNOS-Wt. Clinical, biochemical, and nutritional data were collected up to day 28 of admission.

RESULTS: Ninety-nine adolescents were admitted; 73 had AN and 26 had EDNOS-Wt. Mean (SD) age at admission was 15.2 years (1.3) and 87% were female. In 2005, EDNOS-Wt represented 8% of admissions; by 2009 this proportion had increased to 47%. Hypophosphatemia developed in 41% of AN and in 39% of EDNOS-Wt patients. The lowest mean pulse rate in AN was 45.1 bpm compared with 47.1 bpm in EDNOS-Wt patients.

CONCLUSIONS: We have experienced more than a fivefold increase in the proportion of adolescents who have EDNOS-Wt admitted over this 6-year period. Despite not being underweight, EDNOS-Wt patients experienced a similar profile of life-threatening complications of weight loss as patients who have AN. Higher-weight adolescents who have extensively lost weight require careful medical assessment.