The Natural Course of Bulimia Nervosa and Binge Eating Disorder in Young Women
Total Page:16
File Type:pdf, Size:1020Kb
ORIGINAL ARTICLE The Natural Course of Bulimia Nervosa and Binge Eating Disorder in Young Women Christopher G. Fairburn, DM, MPhil, FRCPsych; Zafra Cooper, DPhil, Dip Clin Psych; Helen A. Doll, MSc; Patricia Norman, MSc; Marianne O’Connor, BA Background: Little is known about the relative ued to meet diagnostic criteria for bulimia nervosa. Each course and outcome of bulimia nervosa and binge eat- year about a third remitted and a third relapsed. The out- ing disorder. come of the binge eating disorder cohort was better, with the proportion with any form of clinical eating disorder Methods: Two community-based cohorts were stud- declining to 18% (7 of 40) by the 5-year follow-up. The ied prospectively over a 5-year year period. One com- relapse rate was low among this cohort. There was little prised 102 participants with bulimia nervosa and the other movement of participants across the 2 diagnostic cat- 48 participants with binge eating disorder (21% [9/42] egories and few sought treatment. Both groups gained of whom had comorbid obesity). All participants were weight, with 39% of the binge eating disorder cohort (14 female and aged between 16 and 35 years at recruit- of 36) meeting criteria for obesity at 5-year follow-up. ment. The assessments were at 15-month intervals and addressed eating disorder features, general psychiatric Conclusions: These findings suggest that, among young symptoms, and social functioning. women in the community, bulimia nervosa and binge eat- ing disorder have a different course and outcome. Whereas Results: Both cohorts showed marked initial improve- the prognosis of those with bulimia nervosa was rela- ment followed by gradual improvement thereafter. Be- tively poor, the great majority of those with binge eating tween half and two thirds of the bulimia nervosa cohort disorder recovered. had some form of eating disorder of clinical severity at each assessment point, although only a minority contin- Arch Gen Psychiatry. 2000;57:659-665 UNDAMENTAL TO the classi- edge, this is the first prospective study to fication of psychiatric disor- compare their longer-term course and out- ders1 and their manage- come. The study was community-based ment is knowledge of their since eating disorders are subject to refer- course and outcome. We de- ral bias.8 Fscribe the findings of a prospective com- munity-based study of the 5-year course RESULTS of 2 eating disorders, bulimia nervosa and binge eating disorder. CHARACTERISTICS The diagnosis of bulimia nervosa was AT RECRUITMENT introduced by Russell in 1979.2 It is char- acterized by recurrent binge eating and ex- The bulimia nervosa cohort comprised 102 treme weight-control behavior, such as self- participants, 92 (90%) of whom were re- induced vomiting, strict dieting, and the assessed by interview at the final fol- misuse of laxatives. Binge eating disorder is low-up (5.0±0.3 years after recruitment). a new diagnostic concept that has provi- Eighty-seven participants were inter- sional status in DSM-IV.3 It too has binge viewed face-to-face, and 5 by telephone. eating as a central feature but, in contrast Of the other 10 participants, 1 could not with bulimia nervosa, there is little or no be traced, 2 did not reply, and 7 declined extreme weight-control behavior.3(p550) The participation. Those not followed up had clinical features of binge eating disorder somewhat more severe symptoms at re- have begun to be delineated and con- cruitment, as indicated by higher frequen- 4-7 From the Department of trasted with those of bulimia nervosa. cies of binge eating (objective bulimic epi- Psychiatry, Oxford University, Much less is known about the relative sodes) and self-induced vomiting (P=.07 Oxford, England. course of the 2 disorders. To our knowl- and P=.13, respectively) and higher scores (REPRINTED) ARCH GEN PSYCHIATRY/ VOL 57, JULY 2000 WWW.ARCHGENPSYCHIATRY.COM 659 Downloaded from www.archgenpsychiatry.com by BettinaIsenschmid, on July 20, 2006 ©2000 American Medical Association. All rights reserved. PARTICIPANTS AND METHODS severity (ie, it was a source of distress or disability3(ppxxi,7 ) that was comparable in severity to that seen among patients at- tending eating disorder clinics). These judgments were made PARTICIPANTS independently, blinded to the participant’s identity, origi- nal diagnosis, and follow-up point. There were few disagree- Two community-based cohorts of female participants ments between the clinicians’ judgments (14/208; 7%), and with DSM-IV eating disorders were recruited and fol- these invariably concerned cases of threshold severity. They lowed up prospectively over a 5-year period. One cohort were resolved on discussion, with the rule being not to make had bulimia nervosa and the other had binge eating dis- an ED-NOS diagnosis if either remained uncertain about case order. The study was approved by the local research eth- status. The same procedure had been used in our study of ics committee. the long-term clinical course of bulimia nervosa.14 The two cohorts were originally recruited for case- control studies of risk factors for bulimia nervosa9 and binge General Psychopathology and Social Adjustment eating disorder.10 They were identified from among women registered with family practices across Oxfordshire, En- A continuous measure of the severity of general psychi- gland. All women aged between 16 and 35 years listed on atric symptoms was provided by the Brief Symptom these registers were sent the self-report version of the Eat- Inventory.15 Sections from the Structured Clinical Inter- ing Disorder Examination interview (EDE).11 Those whose view for DSM-III-R16,17 were used to identify mood and ratings suggested that they might have either eating disor- anxiety disorders at follow-up. Self-esteem was mea- der were subsequently interviewed using the EDE.12,13 Par- sured using the Robson self-esteem questionnaire,18 and ticipants who met DSM-IV diagnostic criteria for bulimia social adjustment was assessed using the Social Adjust- nervosa or binge eating disorder formed the baseline sample. ment Scale.19 Further details of the sample and recruitment methods are given in the original reports.9,10 Exposure to Treatment The participants were recontacted at 15-month inter- vals over 5 years. Those who agreed to be reassessed were Exposure to treatment was assessed at each time point by interviewed face-to-face whenever possible. The great ma- asking the participant about any forms of help that she had jority of the interviews took place in participants’ homes. received, either for the eating problem or for other related Strenuous efforts were made to retain the 2 cohorts. difficulties. MEASURES STATISTICAL METHODS Specific Psychopathology The statistical significance of changes from recruitment to follow-up in individual variables was assessed using para- At each assessment point, the EDE interview12,13 was used metric (paired t) or nonparametric (Wilcoxon matched to measure the severity and character of eating disorder psy- pairs or McNemar) tests, as appropriate for the distribu- chopathology. Participants were weighed using calibrated tion of the data. Similarly, the statistical significance of portable scales, and at the initial assessment their height was any differences between groups of participants was also measured (thereby allowing their body mass index [BMI] assessed using parametric (grouped t) or nonparametric to be calculated; weight in kilograms divided by the square tests (Mann-Whitney, x2, or Fisher exact tests). Relation- of height in meters). With this information it was possible ships between continuous variables were assessed using to apply operational definitions of the DSM-IV diagnoses an- the Pearson r correlation coefficient. To examine differ- orexia nervosa, bulimia nervosa, and binge eating disorder. ences between the 2 groups in pattern of change of eating Diagnoses of the residual DSM-IV eating disorder category, disorder status over time (proportion remitted or relapsed eating disorder not otherwise specified (ED-NOS), of which since previous assessment), logistic models of group and binge eating disorder is one example,3(p550) were made by 2 time were fitted.20 experienced clinicians (C.G.F. and Z.C.) after being briefed Data are presented as mean±SD unless otherwise in- in detail about each eligible participant’s clinical status. They dicated. The significance level was set at 2-sided P,.05, were given this diagnosis if they did not meet the diagnos- although because of the number of comparisons per- tic criteria for anorexia nervosa, bulimia nervosa, or binge formed, differences significant at P,.01 are considered most eating disorder, yet clearly had an eating disorder of clinical reliable. on the Brief Symptom Inventory (P=.08) and Social Ad- The cohorts did not differ significantly at baseline justment Scale (P=.03). in terms of age, marital status, or social class (Table 1). The binge eating disorder cohort comprised 48 par- There was, however, a tendency for those with bulimia ticipants, 40 (83%) of whom were reassessed by inter- nervosa to be younger at the onset of their eating disor- view at the final follow-up (5.0±0.3 years after der (P=.06), and they were more likely to have ever re- recruitment). Thirty-six participants were interviewed ceived treatment for an eating disorder (26% vs 5%; Fisher face-to-face, and 4 by telephone. Of the other 8 partici- P=.01). pants, 2 could not be traced, 2 did not reply, and 4 de- There were no significant differences between the clined participation. The characteristics of those fol- cohorts in their frequency of binge eating, EDE Weight lowed up and those not were very similar. Concern and Shape Concern scores, or self-esteem (REPRINTED) ARCH GEN PSYCHIATRY/ VOL 57, JULY 2000 WWW.ARCHGENPSYCHIATRY.COM 660 Downloaded from www.archgenpsychiatry.com by BettinaIsenschmid, on July 20, 2006 ©2000 American Medical Association.