DSM-IV Eating Disorder Diagnostic Criteria May Have Limited Clinical Utility

SAN DIEGO —Most eating disorder diagnoses in general psychiatric outpatient settings may be categorized as eating disorders not otherwise specified (NOS), which suggests that DSM-IV eating disorder diagnostic criteria are currently too restrictive, reported researchers at the 2007 Annual Meeting of the American Psychiatric Association.

“The NOS category was intended to be a residual category, providing a diagnostic option for those relatively infrequent instances in which formal diagnostic criteria were not met,” stated Mark Zimmerman, MD, Associate Professor of Psychiatry and Human Behavior at Brown Medical School in Providence, Rhode Island, and colleagues. “Our finding that eating disorder NOS cases predominated suggests a problem with the DSM-IV nomenclature for these disorders.”

The investigators gathered data on 2,300 psychiatric outpatients (mean age, 38.2), of whom 60.5% were female. Lifetime prevalence of any eating disorder was found in 14.2% of the participants, including those with current diagnoses (6.6%), partial remissions (2.4%), and past diagnoses (5.2%). Among the 165 patients with current diagnoses, 84 had eating disorder NOS. In this subgroup, 19 patients had subthreshold anorexia nervosa, 20 had subthreshold bulimia nervosa, and 27 had subthreshold binge-eating disorder.

“Three-quarters of the patients diagnosed with eating disorder NOS were so diagnosed because they fell below the threshold of one of the three DSM-IV–defined eating disorders,” noted Dr. Zimmerman. When the 63 patients diagnosed with binge-eating disorder are added to the patients who had other forms of eating disorder NOS, 147 of the 165 patients with current eating disorder diagnoses would be categorized as having eating disorder NOS.

Among the 84 patients with an eating disorder NOS other than binge-eating disorder, 10 (11.9%) were principally diagnosed with this condition. Of the remaining 74 patients with eating disorder NOS as an additional diagnosis, 53.9% expressed a desire for treatment.

“This suggests that ... the patients perceived eating disorder NOS to be clinically significant,” the researchers stated. “The high reliability in diagnosing eating disorder NOS, a diagnosis without specified criteria, further suggests that these ‘subthreshold’ conditions were recognizable as clinically significant.”           

—John Merriman

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