Psychological Medicine

Original Articles

The slippery slope: prediction of successful weight maintenance in anorexia nervosa

A. S. Kaplana1a2 c1, B. T. Walsha3, M. Olmsteda1, E. Attiaa3, J. C. Cartera1, M. J. Devlina3, K. M. Pikea3, B. Woodsidea1, W. Rockerta1, C. A. Robertoa3 and M. Paridesa3

a1 Program for Eating Disorders, Toronto General Hospital, University of Toronto, Ontario, Canada

a2 Center for Addiction and Mental Health, Department of Psychiatry, Faculty of Medicine, University of Toronto, Ontario, Canada

a3 Department of Psychiatry, College of Physicians and Surgeons of Columbia University/New York State Psychiatric Institute, New York, NY, USA

Abstract

Background Previous research has found that many patients with anorexia nervosa (AN) are unable to maintain normal weight after weight restoration. The objective of this study was to identify variables that predicted successful weight maintenance among weight-restored AN patients.

Method Ninety-three patients with AN treated at two sites (Toronto and New York) through in-patient or partial hospitalization achieved a minimally normal weight and were then randomly assigned to receive fluoxetine or placebo along with cognitive behavioral therapy (CBT) for 1 year. Clinical, demographic and psychometric variables were assessed after weight restoration prior to randomization and putative predictors of successful weight maintenance at 6 and 12 months were examined.

Results The most powerful predictors of weight maintenance at 6 and 12 months following weight restoration were pre-randomization body mass index (BMI) and the rate of weight loss in the first 28 days following randomization. Higher BMI and lower rate of weight loss were associated with greater likelihood of maintaining a normal BMI at 6 and 12 months. An additional predictor of weight maintenance was site; patients in Toronto fared better than those in New York.

Conclusions This study found that the best predictors of weight maintenance in weight-restored AN patients over 6 and 12 months were the level of weight restoration at the conclusion of acute treatment and the avoidance of weight loss immediately following intensive treatment. These results suggest that outcome might be improved by achieving a higher BMI during structured treatment programs and on preventing weight loss immediately following discharge from such programs.

(Received March 26 2008)

(Revised July 30 2008)

(Accepted August 16 2008)

(Online publication October 10 2008)

Correspondence

c1 Address for correspondence: A. S. Kaplan M.D., FRCP(C), Senior Scientist and Director Research Training, Center for Addiction and Mental Health, Loretta Anne Rogers Chair in Eating Disorders, Toronto General Hospital, and Vice Chairman of Research, Professor of Psychiatry, University of Toronto, 250 College Street, Room 832, Toronto, Ontario, Canada M5T 1R8. (Email: allan_Kaplan@camh.net)

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