136Am J Psychiatry 157:1, January 2000
Predictive Validity of Bulimia Nervosa
as a Diagnostic Category
Pamela K. Keel, Ph.D., James E. Mitchell, M.D., Kathryn B. Miller, M.A.,
Traci L. Davis, B.A., and Scott J. Crow, M.D.
Objective: The authors sought to investigate the predictive validity of bulimia nervosa as
a diagnostic category. Method: More than 10 years after they appeared as patients with
bulimia nervosa, 177 women (participation rate=79.7%) completed follow-up assessments.
Results: Among the women with a current eating pathology, most engaged in recurrent
binge eating and purging. Anorexia nervosa and binge eating disorder were relatively un-
common. Eating disorder outcome was significantly related to the presence of mood, sub-
stance use, and impulse control disorders but not to the presence of anxiety disorders.
Conclusions: These results support the validity of bulimia nervosa as a diagnostic cate-
gory that is distinct from anorexia nervosa. Furthermore, these results suggest that bulimic
symptoms are associated with disorders involving distress and disinhibition.
(Am J Psychiatry 2000; 157:136–138)
Bulimic symptoms were recognized in anorexia ner-
vosa long before bulimia nervosa was delineated as a
distinct syndrome (1). The delay in recognizing bu-
limia nervosa may have been partially attributable to
the observed crossover of patients from anorexia ner-
vosa to bulimia nervosa. Indeed, early debates centered
on whether bulimia represented an end stage of anor-
exia nervosa, a subgroup of women with anorexia ner-
vosa, or a separate syndrome (1). More recently, some
authors have argued that “bulimia nervosa and binge
eating disorder may not represent distinct nosological
entities” (2, p. 382). Recommendations to consolidate
all eating disorders as one diagnosis have been made as
well (3). Information concerning long-term outcome
can determine the predictive validity of bulimia ner-
vosa as a distinct diagnostic category. However, little is
known regarding long-term outcome, given bulimia
nervosa’s recent delineation as a syndrome.
This study sought to investigate the predictive valid-
ity of bulimia nervosa as a diagnostic category. Addi-
tionally, we explored the relation of eating disorder
outcome to other axis I disorders.
Subjects (N=222) who were diagnosed with bulimia nervosa dur-
ing their participation in a study at the University of Minnesota (4,
5) were assessed a mean length of 11.5 years (SD=1.9) after presen-
tation. At baseline the women met the DSM-III criteria for bulimia
and the additional criterion of binge eating and purging at least three
times each week for 6 months. Additional baseline inclusion and ex-
clusion criteria are presented elsewhere (4, 5).
Of the 222 subjects we sought for follow-up assessment, 22
(9.9%) could not be located, one (0.5%) was deceased, one (0.5%)
was severely disabled, and 21 (9.5%) declined or did not complete
participation. Thus, 177 women (79.7%) participated. Participants
and nonparticipants did not differ significantly on baseline demo-
graphic variables or severity of disorder (6). The women had a mean
age of 35.3 years (SD=5.1) and were predominantly Caucasian
After a complete study description, written informed consent was
obtained from the subjects. The subjects completed the Structured
Clinical Interview for DSM-IV Axis I Disorders (7) and the Hamil-
ton Rating Scale for Depression (8). Reliability estimates were gener-
ally high (Cronbach’s alpha r=0.82 and kappa=0.73–1.00). Data
were analyzed by using SPSS for the Macintosh. Tests were two-
tailed with an alpha of 0.01.
Eating disorder outcome was defined both as categorical and con-
tinuous variables. The categorical definition distinguished between
the women who met the DSM-IV criteria for an eating disorder and
the women who were free from recurrent eating disorder symptoms
during the month preceding the assessment. The continuous defini-
tion represented the natural log of months between the most recent
binge or purge episode and the assessment.
Received Jan. 8, 1999; revision received May 12, 1999;
accepted June 17, 1999. From the Department of Psychology and
the Department of Psychiatry, the University of Minnesota, Minne-
apolis. Address reprint requests to Dr. Keel, 1102 William James
Hall, Harvard University, 33 Kirkland St., Cambridge, MA 02138;
Supported in part by a McKnight grant for eating disorders
research, Obesity Center grant DK-50456 from the National Insti-
tute of Diabetes and Digestive and Kidney Diseases, NIMH
research training grant MH-17069, and dissertation grants from
the American Psychological Association, the Minnesota Women
Psychologists’ Association, and the University of Minnesota.
The authors thank K. Ball, M. Biaocchi, R. Crosby, E. Eckert, S.
Engbloom, D. Glotter, G. Goff, J. Harper, D. Hatsukami, G. Leon,
C. Peterson, C. Pomeroy, R. Pyle, J. Rodefer, and R. Zimmerman
for their help.