restricter-purger differences in bulimic adolescent females

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Restricter-purger Differences in Bulimic Adolescent Females Gail Post, Ph.D. Janis H. Crowther, Ph.D. This study identifies variables that discriminated purging (n = 24) from restricting (n = 29) bulimic adolescent females within a high school setting. A discriminant function analysis identified six variables that significantly differentiated these two groups, including disturbed eating attitudes, a negative perception of body image and weight, involvement in a steady dating relationship, birth order, and marijuana use. Post hoc student's t-tests indicated significant differences between groups on only one variable. Purging bulimics viewed themselves as significantly more over- weight, despite the absence of any significant difference in actual body weight deviation between groups. These findings implicate body image disturbance as re- lated to the more severe behavioral manifestations of this disorder and suggest the emergence of a "restricter-purger" dimension among bulimic adolescent samples. Future research is needed to clarify the importance of this dimension in both ado- lescent and adult clinical populations. INTRODUCTION Bulimia has been identified as a serious eating disorder characterized by mal- adaptive eating attitudes and behaviors (e.g., Herzog, 1982; Pyle et al., 1981), body image dissatisfaction (e.g., Harper et al., 1984), and psychopathology (e.g., Katzman & Wolchik, 1984; Weiss & Ebert, 1983). Historically, an individ- ual had to engage in frequent binge eating and purging either via self-induced vomiting or laxative abuse to receive a diagnosis of bulimia (e.g., Russell, 1979). However, with the publication of DSM-I11 (APA, 1980), a cyclical pattern of binging and fasting (without the presence of purging behaviors) may also warrant a diagnosis of bulimia, provided the corresponding affective and cog- nitive features are present. Although this restricting-purging dimension has Gail Post, Ph.D., is Coordinator of Psychological Services for the Weight Management Program at St. Vincent Charity Hospital, Cleveland, Ohio. Janis H. Crowther, Ph.D., is Associate Professor of Psy- chology at Kent State University. Please address correspondence to Gail Post, Ph.D., Eating Disorders Center, St. Vincent Charity Hospital, 2351 East 22nd Street, Cleveland, Ohio, 44115. international /ourna/ of Eating Disorders, Vol. 6, No. 6, 757-761 (1987) 0 1987 by John Wiley & Sons, Inc. CCC 0276-34781871060757-05$04.00

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Restricter-purger Differences in Bulimic Adolescent Females

Gail Post, Ph.D. Janis H. Crowther, Ph.D.

This study identifies variables that discriminated purging (n = 24) from restricting (n = 29) bulimic adolescent females within a high school setting. A discriminant function analysis identified six variables that significantly differentiated these two groups, including disturbed eating attitudes, a negative perception of body image and weight, involvement in a steady dating relationship, birth order, and marijuana use. Post hoc student's t-tests indicated significant differences between groups on only one variable. Purging bulimics viewed themselves as significantly more over- weight, despite the absence of any significant difference in actual body weight deviation between groups. These findings implicate body image disturbance as re- lated to the more severe behavioral manifestations of this disorder and suggest the emergence of a "restricter-purger" dimension among bulimic adolescent samples. Future research is needed to clarify the importance of this dimension in both ado- lescent and adult clinical populations.

INTRODUCTION

Bulimia has been identified as a serious eating disorder characterized by mal- adaptive eating attitudes and behaviors (e.g., Herzog, 1982; Pyle et al., 1981), body image dissatisfaction (e.g., Harper et al., 1984), and psychopathology (e.g., Katzman & Wolchik, 1984; Weiss & Ebert, 1983). Historically, an individ- ual had to engage in frequent binge eating and purging either via self-induced vomiting or laxative abuse to receive a diagnosis of bulimia (e.g., Russell, 1979). However, with the publication of DSM-I11 (APA, 1980), a cyclical pattern of binging and fasting (without the presence of purging behaviors) may also warrant a diagnosis of bulimia, provided the corresponding affective and cog- nitive features are present. Although this restricting-purging dimension has

Gail Post, Ph.D., is Coordinator of Psychological Services for the Weight Management Program at St. Vincent Charity Hospital, Cleveland, Ohio. Janis H. Crowther, Ph.D., i s Associate Professor of Psy- chology at Kent State University. Please address correspondence to Gail Post, Ph.D., Eating Disorders Center, St. Vincent Charity Hospital, 2351 East 22nd Street, Cleveland, Ohio, 44115.

international /ourna/ of Eating Disorders, Vol. 6, No. 6, 757-761 (1987) 0 1987 by John Wiley & Sons, Inc. CCC 0276-34781871060757 -05$04.00

758 Post and Crowther

been identified as a significant diagnostic and prognostic variable in anorexia nervosa, with purging behaviors associated with poor prognosis, chronicity, and greater psychopathology (e.g., Beaumont et al., 1976; Casper et al., 1980; Garfinkel et al., 1980; Russell, 1979), there has been little research comparing ”restricting” and ”purging” bulimics. Such research could have implications for the diagnosis and treatment of bulimia.

Although it has been established that the onset of bulimia typically occurs during adolescence (e.g., Mitchell & Pyle, 1983), researchers have just begun to investigate the prevalence and characteristics of bulimia in high school pop- ulations (e.g., Crowther et al., 1985; Van Thorre & Vogel, 1985). Recently, a composite of variables differentiating bulimic from nonbulimic high school girls was identified consisting of depressive symptomatology, disturbed eating atti- tudes and behaviors, negative perceptions of weight and body image, and al- cohol use (Post & Crowther, 1985). The purpose of the present study was to refine analyses of this sample of bulimic adolescent girls in order to identify a composite of demographic, personality, and attitudinal characteristics that op- timally discriminate “restricting” from “purging” bulimic adolescents.

METHOD

Subjects

Subjects were 53 bulimic adolescent girls recruited for participation in a larger study from four local high schools. (See Crowther et al., 1985, for a description of the larger sample.) These girls were identified as bulimic on the basis of their responses to questions tapping the DSM-I11 (APA, 1980) criteria for bulimia. A subject was identified as bulimic if she reported that (1) she engages in binge eating; (2) she feels distressed by, and not in control of, her binge eating; (3) binge eating is accompanied by at least three of the following: (a) weight fluctuations of 10 lb or more, (b) fasting or purging as a means of weight control, (c) the consumption of high calorie foods during a binge, (d) secretive eating during a binge, or (e) termination of a binge because of abdom- inal pain or self-induced vomiting; and (4) binge eating is accompanied and/or followed by feelings of depression and/or guilt.

These 53 bulimic subjects were placed in one of the following two groups: (1) purging bulimic (PB) group ( n = 24), consisting of subjects (age: x = 16.4, SD = 1.0) who currently engage in self-induced vomiting or laxative abuse, with or without fasting behavior; and (2) a restricting bulimic (RB) group ( n = 29), consisting of subjects (age: x = 15.9, SD = 1.2) who currently engage in fasting but do not engage in purging behaviors. Student’s t-tests and chi- square analyses comparing the two groups on age, race, grade point average (GPA), parents’ marital status, and family socioeconomic status (Hollingshead & Redlich, 1958) were nonsignificant.

The mean heights and weights of the PB and RB subjects were 64.8 in. (SD = 2.2) and 128.1 Ib (SD = 13.2), and 64.0 in. (SD = 1.9) and 127.1 Ib (SD = 12.9), respectively. To control for the effects of age and height on weight, a body weight deviation (derived from age and height norms estab- lished by the American Child Health Association, 1983) was calculated for each

Restricter-purger Variables in Bulimics 759

subject. A t-test comparing the PB and RB subjects on body weight deviation (PB: x = 0.069, SD = .12; RB: x = 0.075, SD = 0.12) was nonsignificant.

Procedure

Once informed consent from a parent or guardian was obtained, subjects consenting to participate in the study reported to separate classrooms desig- nated for the study and completed the Life History Questionnaire (LHQ; Crowther et al., 1982), Eating Attitudes Test (EAT; Gamer & Garfinkel, 1979), Beck Depression Inventory (BDI; Beck, 1967), Body Cathexis Scale (BCS; Se- cord & Jourard, 1953), and Self-Esteem Scale (SES; Rosenberg, 1965).

RESULTS

Frequency of Binging, Fasting, and Purging Behaviors

Results indicated that 37.5% of the PB group and 27.6% of the RB group reported binging once per week or more. A chi-square analysis of binge eating frequency was significant, x2 (4) = 9.95, p < .05, indicating a higher frequency of binging for the PB group. A t-test comparing mean age of onset for binging (PB: x = 14.0 years, SD = 1.3; RB: x = 13.5 years, SD = 1.4) was nonsignif- icant.

Although 20.6% of the RB group reported use of fasting once per week or more, 50.0% of the PB subjects reported fasting with similar frequency. A chi- square analysis of frequency of fasting was significant, x2 (4j = 10.25, p < .05, indicating more frequent use of fasting among the PB group. Self-induced vomiting was reported by 79.2% of the PB subjects; of this group, 8.3% indi- cated purging 2-6 times per week, and 12.5% purged at least once a day. Use of laxatives was reported by fewer of the PB subjects (41.7%), with only 4.2% using laxatives on a weekly basis. PB subjects began purging at a mean age of 14.8 years (SD = 0.7) for a duration of 1.6 years.

Stepwise Discriminant Function Analysis of PB and RB Groups

A stepwise discriminant function analysis was performed to identify vari- ables that significantly discriminate the PB from the RB group. In addition to the EAT, SES, BCS, and BDI scores, the following variables from the LHQ were entered into the analysis: socioeconomic status, GPA, birth order, in- volvement in a steady dating relationship, number of diets in the past year, discrepancy in pounds between current and ideal weight, importance of achieving ideal weight (five-point Likert scale from very important to very un- important), perception of current weight (five-point Likert scale from very un- derweight to very overweight), perceived degree of stress experienced in the past year (five-point Likert scale from much more than people my age to much less than people my age), and frequency of alcohol and marijuana use in the past month.

Results yielded a Wilks’ lambda of 0.74 (approximation to chi-square = 14.15, df = 6, p < .05), indicating a significant discriminant function between

Post and Crowther 760

the two groups. The canonical correlation (.50) pointed to a moderate associa- tion between the two groups and the function, with 25% of the variance in the function attributed to the two groups. Six of the variables were significant. These consisted of (in order of importance as determined by the standardized canonical coefficients): (1) EAT scores (.59), (2) involvement in a steady dating relationship (.55), (3) perception of current weight (.49), (4) importance of achieving ideal weight (.39), (5) birth order (.39), and (6) marijuana use (.39). The overall percentage of correct group classification was 67.9%. Post-hoc t- tests calculated on these six variables yielded significant differences between the two groups on perception of current weight, t(51) = 2.26, p < .05, indicat- ing that PB subjects perceive themselves as significantly more overweight than do the RB subjects.

DISCUSSION

These results indicated that six variables, including disturbed eating atti- tudes, negative expectations regarding weight and body image, involvement in a steady dating relationship, marijuana use, and birth order, were able to significantly discriminate purging from restricting bulimic adolescent girls. Al- though the significant discriminant function analysis identified restricting- purging differences in a mildly affected bulimic population, only one of the variables allowed for a significant differentiation between groups. Purging bu- limic adolescents viewed themselves as significantly more overweight than re- stricting bulimic adolescents, despite the absence of any significant difference in actual body weight deviation. This suggests that severity of body image distortion is associated with severity of bulimic symptomatology. In direct sup- port of this finding is evidence from the anorexia literature indicating that binge-vomiting anorexics demonstrate greater distortion of body size estima- tion than do fasting anorexics (e.g., Strober et al., 1979). Clearly, body image disturbance should be carefully evaluated in the diagnosis and treatment of adolescents with bulimia.

Despite these implications, the results do not provide the striking contrasts between restricting and purging groups as those reported in the anorexia lit- erature (e.g., Garfinkel et al., 1980). Although it is possible that in an adoles- cent population bulimia is a homogeneous syndrome in which cognitive/ affective components are more critical features than the presence or absence of purging behaviors, it seems more likely that the absence of more distinct res- tricter-purger differences can be attributed to the nature of the subject sample. Subjects in the present research were recruited through local high schools, not treatment settings. Although some of the subjects may have resembled adoles- cent bulimics seeking treatment, the relatively infrequent occurrence of fasting and purging behaviors may have minimized group differences. Investigation of a sample of bulimics demonstrating more frequent and severe bulimic symp- tomatology might have permitted identification of a more distinct dichotomy. In addition, the relatively recent onset of the disorder in this sample may have limited this study’s ability to differentiate restricting bulimics who will never engage in purging behaviors from those who will develop them over time. In reports of clinical samples of adult bulimics, purging symptoms often develop

Restricter-purger Variables in Bulimics 7 6 1

several years after the onset of bingng (e.g., Russell, 1979). Thus, some of the restricting bulimics in the present study may resemble the purging bulimics on cognitive, affective, and behavioral variables because they do not yet manifest purging symptomatology. Despite these sampling considerations, the results of the present research suggest the emergence of restricting-purging differ- ences in a nonclinical adolescent female population. Future research with both adolescent and adult clinical populations is needed to clarify the importance of the restricting-purging dimension in bulimia.

REFERENCES

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American Psychiatric Association. (1980). Diagnostic and Statistical manual of mental disorders (3rd ed.). Washington, D.C.: Author.

Beaumont, P., George, C., & Smart, D. (1976). “Dieters” and “vomiters and purgers” in anorexia nervosa. Psychological Medicine, 6, 617-622.

Beck, A. (1967). Depression: causes and treatmolt. Philadelphia, PA: University of Pennsylvania Press.

Casper, R., Eckert, E., Halmi, K., Goldberg, S., & Davis, J. (1980). Bulimia: Its incidence and clinical importance in patients with anorexia nervosa. Archives of General Psychiatry, 37, 1030- 1035.

Crowther, J., Wolf, E., Post, G., & Brandon, C. (1982). Life History Questionnaire. Unpublished manuscript, Kent State University, Kent, Ohio.

Crowther, J., Post, G., & Zaynor, L. (1985). The prevalence of bulimia and binge eating in adoles- cent girls. International journal of Eating Disorders, 4, 29-42.

Garfinkel, P., Moldofsky, H., & Garner, D. (1980). The heterogeneity of anorexia nervosa: Bulimia as a distinct subgroup. Archives of General Psychiatry, 37, 1036-1040.

Gamer, D., & Garfinkel, P. (1979). The Eating Attitudes Test: An index of the symptoms of an- orexia nervosa. Psychological Medicine, 9, 273-279.

Harper, L., Crowther, J., & Graham, J. (1984). Body image disturbance in women with eating disorders. Paper presented at the 56th Annual Meeting of the Midwestern Psychological Asso- ciation, Chicago, Illinois.

Herzog, D. (1982). Bulimia: The secretive syndrome. Psychosomatics, 23, 481-483. Hollingshead, A., & Redlich, F. (1958). Social class and mental illness: A community study. New York:

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Post, G., & Crowther, J. (1985). Variables that discriminate bulimic from non-bulimic adolescent females. Journal of Youth and Adolescence, 14, 85-98.

Pyle, R., Mitchell, J., & Eckert, E. (1981). Bulimia: Report of thirty-four cases. journal of Clinical Psychiatry, 42, 60-64.

Rosenberg, M. (1965). Society and the adolescent self-image. Princeton, N.J.: Princeton University Press.

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