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Obsessive compulsiveness and physical activity in anorexia nervosa and high-level exercising
Journal of Psychosomatic Research, Vol. 39, No. 8, pp. 967-976, 1995 Copyright © 1995 Elsevier Science Inc. Printed in Great Britain. All rights reserved. 0022-3999/95 $29.00 + 0.00
Pergamon 0022-3999(95)00064-P
OBSESSIVE COMPULSIVENESS A N D PHYSICAL ACTIVITY IN ANOREXIA NERVOSA A N D HIGH-LEVEL EXERCISING C A R O L I N E DAVIS**~§ S I D N E Y H. K E N N E D Y * t , § ELIZABETH RALEVSKI,§ MICHELLE DIONNE,§ HOWARD BREWER,§ CHRISTINA NEITZERT~ and DOROTHY RATUSNY,
(Received 22 July 1994; accepted 16 March 1995) Abstract- Although excessivephysical activity and obsessive compulsiveness are both prevalent in anorexia nervosa (AN), to date, the association between these two factors has not been systematically investigated. The aim of the present study was to investigate the relationship between obsessive compulsiveness and both behavioral and psychological aspects of exercise in women with AN, and to compare them to a nonclinical sample of females classified as either moderate or high-level exercisers. Results indicated that obsessive compulsiveness, weight preoccupation, and pathological aspects of exercise were significantly related to the level of physical activity among the eating disorder patients. For the high-level exercisers, only obsessive compulsiveness was significantly related to the amount of physical activity. The findings are discussed in terms of a model in which physical activity, starvation, and obsessive compulsiveness are reciprocally and dynamically related, with each factor creating a destructive bidirectional loop that is resistant to change and difficult to break. We propose that this self-perpetuating loop may be a significant influence in the development and maintenance of eating disorders in a certain subgroup of women.
Keywords: Anorexia nervosa, Exercising, Obsessive-compulsive disorder, Physical activity. INTRODUCTION Over the p a s t several d e c a d e s there has been increasing evidence o f a c o n n e c t i o n between neurotic obsessions a n d compulsions, a n d the eating disorders. A m o n g the p r o m inent p s y c h o l o g i c a l characteristics a s s o c i a t e d with obsessive c o m p u l s i v e n e s s is perfect i o n i s m a n d risk-aversion whereby the extreme c a u t i o n m a n i f e s t e d by these individuals seems to reflect a strong a n t i c i p a t i o n o f negative o u t c o m e s , b a s e d m o r e o n the a b s e n c e o f d i s c o n f i r m i n g evidence t h a n o n the presence o f " d a n g e r signals" [1]. These indiv i d u a l s are also c h a r a c t e r i z e d by intrusive t h o u g h t s a n d by v a r i o u s compulsive, ritualized, a n d stereotyped b e h a v i o u r s like frequent checking a n d hand-washing. E a r l y c o m parisons between obsessive patients a n d anorectic patients indicated a close resemblance in m a n y aspects o f their s y m p t o m a t o l o g y [e.g., 2-4]. Recent reviewers have also conc l u d e d that, in general, there is a high o c c u r r e n c e o f o b s e s s i v e - c o m p u l s i v e d i s o r d e r ( O C D ) s y m p t o m s in e a t i n g disorders, a n d t h a t a n o r e x i a n e r v o s a ( A N ) p a t i e n t s tend
* Department of Psychiatry, The Toronto Hospital. ? Department of Psychiatry, University of Toronto. Graduate Programme in Exercise and Health Science, York University. § Graduate Programme in Psychology, York University. Address correspondence to: Dr. Caroline Davis, 343 Bethune College, York University, 4700 Keele St., North York, Ontario, M3J IP3, Canada. 967
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to have personality traits such as rigidity, restraint in emotional expression, and greater impulse control, which are highly compatible with obsessive-compulsive personality disorder (OCPD)* [6, 7]. However, the extent to which obsessionality is an antecedent, or a consequence, of starvation is less dear. Strober (1980) found that although there was a significant decrease in the extent and severity of symptom obsessionality after weight-restoration, there was no change in the obsessional personality characteristics of AN patients [3]. He suggested, therefore, that these traits may have a facilitating effect on the more general obsessive and compulsive symptoms that emerge during the acute phase of the disorder, particularly in the context of ritualized eating and preoccupations about weight. Others have also concluded that while premorbid obsessional personality traits are, in fact, over-represented in AN patients, the progression of the illness does tend to exacerbate obsessional thoughts and compulsive behaviours [8, 9]. Not only are there clinical similarities between AN and OCD, but there appears to be a neurochemical correspondence. Since interventions that increase intrasynaptic serotonin (5-HT) or directly activate 5-HT receptors tend to reduce food consumption in experimental animals and contribute to obsessive and anxious behaviour in humans, Kaye et al. (1993) propose the theoretical possibility that chronically increased 5-HT activity could be causally implicated in the pathogenesis of both AN and OCD [7]. Indeed, there is good evidence of altered serotonergic function in OCD patients as well as in AN patients [7, 10-12]. Although the mechanism of action is currently unclear, the notion of 5-HT dysregulation is supported by the effectiveness of serotonergic reuptake inhibitors, such as fluoxetine, in the treatment of OCD [e.g., 13, see 14 for a review] as well as in the treatment of AN [see 6 and 7, for reviews]. Hyperactivity is a salient feature of AN and is significant in its link with obsessive compulsiveness. Relentless and excessive exercising has been reported among eatingdisordered patients throughout the history of the disorder [e.g., 15-21]. Traditionally, this behaviour was viewed simply as an analogue of purgation- that is, as a deliberate method of expending unwanted calories. Some have argued, however, that it occupies a more central role in pathogenesis of the disorder [20-24]. Of relevance to these claims is the activity-induced weight-loss syndrome whereby experimental rats with access to a running wheel begin to increase their running when food intake is restricted to 60 to 90 min/day [e.g., 23, 25-28]. Typically, they exhibit decompensated eating behaviour within one week with exponentially increasing activity and decreasing food intake. In the original experiments, the animals literally ran themselves to death! Since the mid-1960s, this robust animal model has been demonstrated in a number of studies, and has subsequently been proposed as a biobehavioural model for AN [20, 24]. Until recently, however, evidence supporting the notion of activity-induced anorexia in the human condition was based solely on anecdote and isolated case reports [e.g., 20, 29]. In a recent clinical study, we found a remarkable similarity with the relationship between activity and starvation in an AN population and the previous reports of activityinduced anorexia in animals [21]. Seventy-five percent of the patient sample reported
* Although OCD and OCPD are frequentlydiscussedinterchangeably,the degreeof comorbiditybetweenthe two syndromes (as definedby DSM-III-R) is relativelysmall(6%), indicatingthat OCPD is not invariablya premorbid condition for the development of OCD [5].
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a n inverse r e l a t i o n s h i p b e t w e e n f o o d i n t a k e a n d degree o f physical a c t i v i t y d u r i n g the acute weight-loss p h a s e o f their disorder. These p a t i e n t s also i n d i c a t e d t h a t their exercising e v e n t u a l l y b e c a m e a c o m p u l s i v e a n d r i t u a l i z e d b e h a v i o u r - an activity t h a t they d e s c r i b e d as "obsessive, .... driven," a n d " o u t o f c o n t r o l . " Recent research suggests t h a t the activity-induced weight-loss b e h a v i o u r p a t t e r n m a y also be a valid a n i m a l m o d e l o f O C D . F o r example, a series o f studies has identified region-specific 5 - H T a b n o r m a l i t i e s in a n i m a l s t h a t were specific to this s y n d r o m e a n d were n o t a general c o n s e q u e n c e o f either weight loss o r exercise a l o n e [27]. A l t e m u s et al. (1993) also f o u n d that, c o m p a r e d to saline- o r i m i p r a m i n e - t r e a t e d rats, rats p r e t r e a t e d with fluoxetine showed a significant a t t e n u a t i o n o f activity, anorexia, a n d weight loss w h e n e x p o s e d to the e x p e r i m e n t a l p r o c e d u r e s d e s c r i b e d a b o v e [26]. Together these studies indicate, indirectly, t h a t exercise a n d starvation, in concert, m a y alter 5 - H T f u n c t i o n i n g a n d e x a c e r b a t e obsessionality. M u c h c o n t r o v e r s y followed the claim, in 1983, t h a t high-level exercising was a n a n a logue o f A N [30]. M o r e recently, Yates has m a d e a strong case, b a s e d o n a wealth o f clinical o b s e r v a t i o n a n d p s y c h o l o g i c a l assessment, t h a t excessive exercisers t y p i c a l l y d i s p l a y a c o m p u l s i v e b e h a v i o u r p a t t e r n a n d are c h a r a c t e r i z e d by an o b s e s s i o n a l a n d rigid p e r s o n a l i t y profile [19]. W h e n o n e considers the t o t a l i t y o f research in this area, there is converging a n d c o m p e l l i n g evidence t h a t physical activity plays a c a t a l y t i c role in the f o r m a t i o n o f a d y n a m i c t r i a d o f related factors (that i n c l u d e obsessive c o m p u l siveness a n d dieting) t h a t feature in the p a t h o g e n e s i s o f e a t i n g disorders. A l t h o u g h there is a small b o d y o f n o n c l i n i c a l research t h a t has d e m o n s t r a t e d an a s s o c i a t i o n between obsessive c o m p u l s i v e n e s s a n d b o t h the frequency [31, 32] a n d the o b l i g a t o r y a n d p a t h o l o g i c a l aspects o f exercising [33], we are unaware o f any research t h a t has s y s t e m a t i c a l l y investigated the r e l a t i o n s h i p between obsessive compulsiveness a n d exercise in clinical samples. T h e present s t u d y was designed, therefore, to investigate these a s s o c i a t i o n s a m o n g eating d i s o r d e r e d patients, as well as to m a k e c o m p a r isons between p a t i e n t s a n d a n o n c l i n i c a l s a m p l e o f exercising w o m e n - b o t h m o d e r a t e exercisers a n d t h o s e w h o are classified as high-level exercisers.
METHOD Subjects Sample 1. Consecutive female patients under the age of 35 who were admitted to the inpatient unit of the Programme for Eating Disorders at The Toronto Hospital over a two and a half year period were considered eligible for assessment. However, for the purposes of this study, only those patients who presented with AN or those who had, within the previous year, satisfied DSM-III-R criteria for AN, were included in the present analyses. Forty-six patients met the inclusion criteria (mean age = 24.2, s = 4.7). Sample 2. As part of a previous investigation of certain psychological aspects of exercising, a large sample of regularly exercising adult men and women were assessed. In order to represent the same age range as the patient sample, only women under the age of 35 were included in the analyses (mean age = 23.3, s = 3.8). This sample was dichotomized according to frequency and duration of exercising. According to a criterion commonly used in previous research, those who were exercising, on average, a minimum of 5 hours per week [e.g., 34, 35] during the year prior to assessment, were classified as "high-level exercisers" (n = 33). The remaining women were classified as "moderate exercisers" (n = 55). Subjects were solicited from the recreation facilities at the university and from a number of health and fitness clubs and YMCAs in the metropolitan Toronto area. Advertisements were posted at these facilities, and notices were put in their newsletters and fliers. Sample 3. Since some aspects of the psychometric data obtained from the patient sample were not available for the subjects in sample 2, a second sample of high-level exercising women, under the age of 35, was used for comparison. These subjects are part of a large on-going prospective exercise study. In order
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to participate in the study, subjects were required to exercise a minimum of 5 hours per week in nonteam activities such as running, cycling, swimming, or weight training. Data from 40 women (mean age = 24.7, s = 3.2) are included in this sample.
Measurements 1. Obsessive compulsiveness was assessed by the "obsessive-compulsive" subscale of the SCL-90 [36]. This dimension reflects symptoms that are closely identified with OCD, such as thoughts, impulses, and actions that are experienced by the individual as unremitting and irresistible, but of an unwanted nature. There are also items that assess more general cognitive difficulty. This measure was obtained only for subjects in samples 1 and 3. 2. Weight Preoccupation was assessed by the Drive-for-Thinness subscale of the Eating Disorder Inventory [37]. 3. Commitment to Exercise was assessed by the 8-item Commitment to Exercise Scale (CES) [33]. A factor-analyses of the items of this scale have identified two moderately correlated factors that assess the obligatory aspects of exercising (e.g., feelings of guilt when an exercise session is missed, adherence to a fixed and set routine for exercising), and the pathological aspects of exercising (e.g., continuing to exercise in the face of illness or injury). 4. Leisure-Time Physical Activity Participation: Using a structured interview format, retrospective data were collected, in samples 1 and 2 for the 12 months immediately preceding the testing session.t The interviewer described a number of physical activities (e.g., jogging/running, swimming, cycling, home exercises, dance classes, etc.), and subjects were asked to indicate those in which they had participated regularly, either for sport or for exercise. They were then asked to specify, within the relevant time frame, the number of weeks of participation per year, the average number of sessions of that activity per week, and the average duration of each session in minutes 0-30, 31-60, 61-90, 90+). Physical activity was quantified by multiplying weeks per year by frequency per week by duration per session in half hour units (1, 2, 3, and 4 consecutively) for each activity and summing across all activities. Therefore, each unit reflects half an hour of activity. For sample 3 the data were collected prospectively over a four-week period. Each subject was given instruction on keeping the physical activity diary, which was identical in format to that used in the structured interview in samples 1 and 2. Subjects summarized their activity at the end of each week and returned the diaries to the experimenters at the end of the study. Physical activity was quantified in the manner described above.:~
Procedure All subjects in sample 1 were tested within the first 5 or 6 weeks of admission to the hospital. All of the psychometric data were obtained as part of an admission package that patients were asked to complete in their spare time. The physical activity data were obtained by means of a personal interview [21]. Subjects in samples 2 and 3 were all tested individually, either at the university laboratory or at an equivalent facility provided at the off-campus locations. First the subjects were asked to complete the questionnaire package, and then the physical activity data were obtained. For the subjects in sample 2 this was done by means of a face-to-face interview. In sample 3, subjects recorded their leisure-time physical activity in weekly diaries and returned them to the investigators at the end of a four-week period. RESULTS
Means, standard deviations, and minima and maxima for all variables are presented in Table I, listed separately by group. A series of one-factor analyses of variance were conducted among the patient group, moderate exercisers, and high-level exercisers from sample 2. Results indicated that
t In some cases, patients had been hospitalized at a different institution at some period during the 12 months that preceded the assessment. In these cases, the physical activity variable was prorated to reflect the period of time the patient was at home and therefore able to exercise. In order to make comparisons with the patient group for whom activity was obtained retrospectively for a 12-month period, the 4-week total for sample 3 was multiplied by 12. We recognize the limitations of extrapolating beyond the data collected, but believe the opportunity to replicate the results obtained with sample 2 outweighs the shortcomings of this calculation.
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OCD, AN, and high-level exercising Table I.-Means, standard deviations, minima, and maxima for all variables listed separately by group Variable
Mean
SD
Min.
Max.
Anorexia nervosa patients (n = 46) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity1 Obsessive compulsive Weight preoccupation
71.7 65.0 75.1 25.5 1.8 15.6
18.9 24.0 18.2 14.4 0.9 5.0
15.2 6.4 16.4 1.0 0.1 2.0
100.0 100.0 100.0 63.0 3.7 21.0
High-level exercisers-Sample 2 (n = 33) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Weight preoccupation
69.3 60.9 70.7 39.2 7.4
13.9 17.8 13.5 4.7 7.1
29.4 25.3 34.2 33.5 0.0
97.7 98.4 96.7 50.3 19.0
21.4 4.9 24.8 13.8 0.0
89.8 96.4 91.4 33.1 20.0
Moderate exercisers (n = 55) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Weight preoccupation
57.9 48.8 61.3 24.5 6.2
14.9 20.4 16.0 4.3 6.2
High-level exercisers-Sample 3 (n = 40) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Obsessive compulsive Weight preoccupation
71.0 63.8 75.2 32.7 0.7 5.4
17.5 23.5 15.8 9.4 0.5 5. l
37.5 13. l 40.7 20.8 0.0 0.0
100.0 100.0 100.0 56.8 2.3 18.0
A square root transformation was used to normalize the distribution of physical activity scores. The statistics listed in this table for that variable are, therefore, in square root units.
high-level exercisers engaged in more physical activity than the patient group and the moderate exercisers, but there were no differences between the patients and the moderate exercisers. With respect to the CES (both the total score and the subscales), there were no differences between the patients and the high-level exercisers, but both groups had higher scores than the moderate exercisers. Finally, the patients scored significantly higher than both exercise groups on the measure of weight preoccupation. A summary of these findings appears in Table II. The same comparisons were made between the patient group and the high-level exercisers in sample 3, and the results replicated precisely those reported above. In addition, it was found that the patients had significantly higher obsessive-compulsive scores than high-level exercisers. A summary o f these findings is given in Table III. Table IV presents matrices o f all pairwise correlation coefficients among the following variables: obsessive compulsiveness, weight preoccupation, obligatory aspects of exercising, pathological aspects of exercising, and level of physical activity participation. Values are listed separately for the patient group and for high-level exercisers
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C. DAVIS et al. Table II.-Between-Groups (i.e., AN patients, high-level exercisers, and moderate exercisers) analyses of variance for all dependent variables assessed in Samples 1 and 2
Factor
df
SS
F
Post hoc tests*
p
Dependent variable: Physical activity participation Group 2 5440.5 30.47 <0.0001 Error 130 11426.0
HL>AN: HL>ME
Dependent variable: Attitudes to exercise (total) Group 2 5172.4 9.89 <0.0001 Error 126 32956.0
AN>ME:HL>ME
Dependent variable: Attitudes to exercise (Pathology subscale) Group 2 6747.2 7.63 0.0007 AN>ME: HL>ME Error 128 55731.6 Dependent Variable: Attitudes to Exercise (Obligatory subscale) 4744.4 9.08 0.0002 AN>ME: HL>ME Group 2 Error 128 32935.8 Dependent variable: Weight preoccupation Group 2 2160.2 28.79 <0.0001 Error 122 4502.5
AN>HL: AN>RE
* All post hoc comparisons were calculated using Fisher's least-significant difference test. f r o m sample 3. Results indicate that obsessive compulsiveness, weight preoccupation, and pathological attitudes toward exercise are significantly, and positively, related to level o f activity a m o n g A N patients. In addition, obligatory and pathological aspects o f exercising are related to weight preoccupation. In the exercise group, the only significant relationships were a m o n g obsessive compulsiveness and activity level, and between weight preoccupation and obligatory aspects o f exercising. Table III.-Between-groups analyses of variance for all dependent variables in Samples 1 and 3 Factor
df
SS
F
p
Dependent variable: Physical activity participation Group 1 1105.1 7.25 0.0085 Error 84 11426.0
HL>AN
Dependent variable: Attitudes to exercise (total) Group 1 10.6 0.03 0.8589 Error 126 32956.0 Dependent variable: Attitudes to exercise (Pathology subscale) Group 1 27.1 0.05 0.8274 Error 82 46430.2 Dependent variable: Attitudes to exercise (Obligatory subscale) Group 1 0.3 0.00 0.9729 Error 82 24024.0 Dependent variable: Weight preoccupation Group 1 2070.5 82.33 <0.0001 Error 77 4007.0 Dependent variable: Obsessive compulsiveness Group 1 21.0 39.96 <0.0001 Error 77 40.51
AN>HL
AN>HL
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Table IV.-Correlations between variables for female eating disordered patients and high-level exercisers (Sample 3) O-C ~
0
.
2
WP
PA
5 0.40**
WP PA OBL_I_G. PATH.
0.07 ~ ~ . 3 6 " 0.32* --0.07 ~0.30 0.21 0.37" 0 . 1 7 0.11 0.25 0.08 Exercise Group
OBLIG.
PATH.
Patient Group 0.25 0.22 0.40** 0.33* 0.35** ~ _ 0.80*** 0.85***
O-C = Obsessive Compulsiveness. WP = Weight Preoccupation. PA = Frequency and Duration of Exercise. OBLIG = Obligatory Aspects of Exercising. PATH = Pathological Aspects of Exercising. * p < 0.05 ** p < 0.01 *** p < 0.0001. A proposed activity-anorexia model, based, in part, on the interrelationships among these variables, is outlined in Fig. 1 and will be discussed in the following section. DISCUSSION Rothenberg has claimed that AN is a modern variant of obsessive-compulsive syndrome among women in Western c u l t u r e s - a n opinion he based on the obsessional nature o f their concern with food, their extreme perfectionism, and their preoccupation with matters of control [38, 39]. Prompted by the results of the present study and by the various studies linking O C D and AN, we propose a nonrecursive, theoretical model that integrates, in a dynamic sense, obsessive compulsiveness, physical activity, and starvation in the pathogenesis of some eating disorders (see Fig. 1).
IP r o p o s e d ObsessiveCompulslv
Activity - Anorexia ,. --
Pathological ...... to
(
Model I Drlve-for~ hlnness
Physical Activity Level
Fig. 1. A proposed interactive model of anorexia nervosa based on interrelationships among starvation, physical activity, and obsessive compulsiveness.
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Our model shares similarities with that proposed earlier by Epling and Pierce [20, 2 4 ] - specifically, that under-eating and over-exercise become mutually reinforcing behaviours- but extends its scope by taking account of certain salient psychological factors. We suggest that within the context of a sport or fitness environment, the combination of excessive weight preoccupation and obsessive-compulsive tendencies is likely, in women, to increase the frequency and duration of their physical activity and to exacerbate the obligatory nature of their commitment to this behaviour. In turn, increased physical activity itself may foster greater food restriction by virtue of its appetitesuppressing effects [40] and by encouraging a heightened focus on appearance, weight, and performance [29, 41]. Furthermore, strenuous physical activity and food restriction, in concert, have been shown to alter 5-HT functioning [26, 27] and increase obsessionality [e.g., 7, 21] - a factor that then contributes to even greater increases in physical activity and more rigorous starvation. As a consequence, one's commitment to exercise is likely to degenerate into more pathological attitudes and behaviours as obsessionality increases. In summary, we argue that the relationships among physical activity, starvation, and obsessive compulsiveness tend to be reciprocal and dynamic. In other words, together they potentiate one another in a destructive feedback/feedforward loop that becomes self-perpetuating, resistant to change, and may be a significant influence in the development and maintenance of eating disorders for some women. In agreement with previous research [31-33], we also found a positive relationship between obsessive compulsiveness and exercise frequency in high-level exercisers. Importantly, this also maps onto Yates' (1991) claim that excessive exercising and eating disorders are "sister activities," and strongly related to obsessionality [19]. Nevertheless, although the CES scores of high-level exercisers were as high as patients' scores, the former had, on average, significantly lower scores on obsessive compulsiveness and weight preoccupation. When, we might ask, are high-level exercisers at risk of developing AN? We suggest that assiduous and strenuous exercising is potentially problematic in an individual who is both highly weight preoccupied and characterised by a perfectionistic and obsessive-compulsive personality. As an example, a post hoc inspection of the individual scores for the high-level exercisers in sample 3 identified one (and only one woman [i.e., 2.5 °70of the group]) who scored above the group m e a n - and in this case, in excess of one standard deviation above on all the relevant variables: obsessive compulsiveness, weight preoccupation, the CES subscales, and physical activity level. She also had a relatively low Body Mass Index of 19.1. We suggest that this particular constellation of characteristics may well indicate a subclinical case of AN or, at the very least, a vulnerable premorbid condition that is in danger of developing into the full-blown syndrome. Finally, results of this study also supported the construct validity of the Commitment to Exercise Scale (CES)-- an inventory designed to assess the core features characteristic of those who exercise excessively [33]. For example, high-level exercisers and anorectic patients were not different from each other, but both scored higher than moderate exercisers on both factors of the CES§. In addition, correlational analyses revealed § These findings were also replicated when comparisons were made between AN patients and high-level exercisers from sample 3.
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a significant relationship between weight preoccupation and the obligatory aspects of exercising for high-level exercisers and for AN patients; however, only in the AN group was weight preoccupation related to pathological exercising, which, in turn, was related to level of exercising. Taken together, these findings are in accord with clinical reports that typically describe the relentless, compulsive, and excessive nature of the physical activity observed among AN patients [21, 42, 43]. In conclusion, it is important to emphasize that the aetiology of eating disorders is highly complex and, indeed, variable across cases. For these reasons, we acknowledge that our proposed activity-anorexia model may explain one aspect of the pathogenesis of AN and then only for some individuals. Clearly, this model says little about the motivations that initially trigger exaggerated weight and diet concerns in women, nor does it address the myriad of factors that predispose certain individuals, and not others, to become heavily invested in athletics and exercise.
REFERENCES 1. FROST RO, STEKETEE G, COHN L, GR1ESS K. Personality traits in subclinical and non-obsessivecompulsive volunteers and their parents. Behav Res Ther 1994; 32: 47-56. 2. SMART DE, BEAUMONT P J, GEORGE GC. Some personality characteristics of patients with anorexia nervosa. Br J Psychiatry 1976; 128: 57-60. 3. STROBER M. Personality and symptomatologicai features in young, nonchronic anorexia nervosa patients. J Psychosom Res 1980; 24: 353-359. 4. SOLYOM L, FREEMAN R J, THOMAS CD, MILES JE. The comparative psychopathology of anorexia nervosa: obsessive-compulsive disorder or phobia? Int J Eating Disord 1983; 3: 3-14. 5. BAER L, JENIKE MA, RICCIARDI JN, HOLLAND AD, SEYMOUR RJ, MINICHIELLO WE, BUTTOLPH ML. Standardized assessment of personality disorders in obsessive-compulsive disorder. Arch Gen Psychiatry 1990; 47: 826-830. 6. HSU LKG, KAYE W, WELTZ1N T. Are the eating disorders related to obsessive compulsive disorder? Int J Eating Disord 1993; 14: 305-318. 7. KAYE WH, WELTZIN TE, HSU LKG, BULIK C. An open trial of fluoxetine in patients with anorexia nervosa. J Clin Psychiatry 1991; 52: 464-471. 8. HOLDEN NL. ls anorexia nervosa an obsessive-compulsive disorder? Br J Psychiatry 1990; 157: 1-5. 9. SOHLBERG S, STROBER M. Personality in anorexia nervosa: an update and a theoretical integration. Acta Psychiatr Scand Suppl 1994; 89: 1-15. 10. BASTANI B, NASH F, MELTZER HY. Prolactin and cortisol responses to MK-212, a serotonin agonist, in obsessive-compulsive disorder. Arch Gen Psychiatry 1990; 47: 833-839. 11. MARAZZIT1 D, HOLLANDER E, LENSI P, RAVAGLI S, CASSANO GB. Peripheral markers of serotonin and dopamine function in obsessive-compulsive disorder. PsychiatryRes 1992; 42: 41-51. 12. BARR LC, GOODMAN WK, PRICE LH, MCDOUGLE C J, CHARNEY DS. The serotonin hypothesis of obsessive compulsive disorder: implications of pharmacologic challenge studies. J Clin Psychiatry 1992; 53: 17-28. 13. JENICKE MA, BUTTOLPH L, BAER L, RICCIARDI J, HOLLAND A. Open trial of fluoxetine in obsessive-compulsive disorder. A m J Psychiatry 1989; 146:909-911. 14. ABEL J. Exposure with response prevention and serotonergic antidepressants in the treatment of obsessive compulsive disorder: a review and implications for interdisciplinary treatment. Behav Res Ther 1993; 31: 463-478. 15. GULL WW. Anorexia nervosa. Trans Clin Soc (London) 1874; 7:22-28 cited by Warah A. Overactivity and boundary setting in anorexia nervosa: an existential perspective. JAdolesc 1993; 16: 93-100. 16. INCHES P. Anorexia nervosa. Maritime Med News 1895; 7: 73-75. 17. BRUCH H. Anorexia nervosa - its differential diagnosis. J Nerv Ment Dis 1965; 141: 555-566. 18. CRISP AH. The possible significance of some behavioral correlates of weight and carbohydrate intake. J Psychosom Res 1967; 11: 117-131. 19. YATES A. Compulsive Exercise and the Eating Disorders. New York: Brunner/Mazel, 1991. 20. EPLING WF, PIERCE WD. Solving the Anorexia Puzzle. Toronto: Hogrefe & Huber Publishers, 1992. 21. DAVIS C, KENNEDY SH, RALEVSKI E, DIONNE M. The role of physical activity in the development and maintenance of eating disorders. Psychol Med 1994; 24: 957-967.
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22. KRON L, KATZ JL, GORZYNSKI O, WEINER W. Hyperactivity in anorexia nervosa: a fundamental clinical feature. Compr Psychiatry 1978; 19: 433-439. 23. EPLING WF, PIERCE WD. Activity-based anorexia in rats as a function of opportunity to run on an activity wheel. Nutr Behav 1984; 2: 37-49. 24. EPLING WF, PIERCE WD. Activity-based anorexia: a biobehavioral perspective. Int JEating Disord 1988; 7(4): 475-485. 25. ROUTTENBERG A, KUZNESOF AW. Self-starvation of rats living in activity wheels on a restricted feeding schedule. J Comp Physiol Psychol 1967; 64: 414-421. 26. ALTEMUS M, GLOWA JR, MURPHY DL. Attenuation of food-restriction-induced running by chronic fluoxetine treatment. Psychopharmacol Bull 1993; 29: 397-400. 27. ARAVICH PF, RIEG TS, AHMED I, LAUTERIO TJ. Fluoxetin¢ induces vasopressin and oxytoxin abnormalities in food-restricted rats given voluntary exercise: relationship to anorexia nervosa. Brain Res 1993; 612: 180-189. 28. WONG ML, LICINIO J, GOLD PW, GLOWA J. Activity-induced anorexia in rats does not affect hypothalamic neuropeptide gene expression chronically, lnt J Eating Disord 1993; 13: 399-405. 29. KATZ JL. Long-distance running, anorexia nervosa, and bulimia: a report of two cases. ComprPsychiatry 1986; 27(1): 74-78. 30. YATES A, LEEHEY K, SHISSLAK C. R u n n i n g - a n analogue of anorexia? NEngl JMed 1983; 308(5): 251-255. 31. G O L D F A R B LA, P L A N T E TG. Fear of fat in runners: an examination of the connection between anorexia ncrvosa and distance running. Psychol Rep 1984; 55: 296. 32. K A G A N D. Addictive personality factors. J Psychol 1987; 121(6): 533-538. 33. D A V I S C, B R E W E R H, R A T U S N Y D. Behavioral frequency and psychological commitment: necessary concepts in the study of excessive exercising.J Behav M e d 1993; 16:611-628. 34. D E C O V E R L E Y V E A L E D. Exercise dependence. Br JAddict 1987; 82: 735-740. 35. N U D E L M A N S, R O S E N JC, L E I T E N B E R G H. Dissimilaritiesin eating attitudes,body image distortion,depression,and self-esteembetween high-intensitymale runners and women with bulimia nervosa. Int J Eating Disord 1988; 7: 625-634. 36. D E R O G A T I S LR, R I C K E L S K, R O C K AF. The SCL-90 and the M M P I : a step in the validation of a new self-reportscale. Br J Psychiatry 1976; 128: 280-289. 37. G A R N E R D M , O L M S T E D MP, P O L I V Y J. Development and validationof a multidimensional eating disorder inventory for anorexia nervosa and bulimia nervosa. Int JEating Disord 1983; 2: 15-34. 38. R O T H E N B E R G A. Eating disorder as a modern obsessive-compulsive syndrome. Psychiatry 1986; 49: 45-53. 39. R O T H E N B E R G A. Differentialdiagnosis of anorexia nervosa and depressiveillness:a review of I l studies. Compr Psychiatry 1988; 29: 427-432. 40. R I V E S T S, R I C H A R D D. Involvement of corticotropin-releasingfactor in the anorexia induced by exercise. Brain Res Bull 1990; 25: 169-172. 41. D A V I S C. Body image, dietingbehaviours, and personalityfactors:a study of high-performance female athletes.Int J Sport Psychol 1992; 23: 179-192. 42. L O N G C, S M I T H J. Treatment of compulsive over-exercisingin anorexia nervosa: a case study. Behay Psychother 1990; 18: 295-306. 43. B E U M O N T PJV, A R T H U R B, R U S S E L L JD, T O U Y Z SW. Excessive physical activityin dieting disorder patients:proposals for a supervised exerciseprogram. Int JEating Disord 1994; 15: 21-36.
Pergamon 0022-3999(95)00064-P
OBSESSIVE COMPULSIVENESS A N D PHYSICAL ACTIVITY IN ANOREXIA NERVOSA A N D HIGH-LEVEL EXERCISING C A R O L I N E DAVIS**~§ S I D N E Y H. K E N N E D Y * t , § ELIZABETH RALEVSKI,§ MICHELLE DIONNE,§ HOWARD BREWER,§ CHRISTINA NEITZERT~ and DOROTHY RATUSNY,
(Received 22 July 1994; accepted 16 March 1995) Abstract- Although excessivephysical activity and obsessive compulsiveness are both prevalent in anorexia nervosa (AN), to date, the association between these two factors has not been systematically investigated. The aim of the present study was to investigate the relationship between obsessive compulsiveness and both behavioral and psychological aspects of exercise in women with AN, and to compare them to a nonclinical sample of females classified as either moderate or high-level exercisers. Results indicated that obsessive compulsiveness, weight preoccupation, and pathological aspects of exercise were significantly related to the level of physical activity among the eating disorder patients. For the high-level exercisers, only obsessive compulsiveness was significantly related to the amount of physical activity. The findings are discussed in terms of a model in which physical activity, starvation, and obsessive compulsiveness are reciprocally and dynamically related, with each factor creating a destructive bidirectional loop that is resistant to change and difficult to break. We propose that this self-perpetuating loop may be a significant influence in the development and maintenance of eating disorders in a certain subgroup of women.
Keywords: Anorexia nervosa, Exercising, Obsessive-compulsive disorder, Physical activity. INTRODUCTION Over the p a s t several d e c a d e s there has been increasing evidence o f a c o n n e c t i o n between neurotic obsessions a n d compulsions, a n d the eating disorders. A m o n g the p r o m inent p s y c h o l o g i c a l characteristics a s s o c i a t e d with obsessive c o m p u l s i v e n e s s is perfect i o n i s m a n d risk-aversion whereby the extreme c a u t i o n m a n i f e s t e d by these individuals seems to reflect a strong a n t i c i p a t i o n o f negative o u t c o m e s , b a s e d m o r e o n the a b s e n c e o f d i s c o n f i r m i n g evidence t h a n o n the presence o f " d a n g e r signals" [1]. These indiv i d u a l s are also c h a r a c t e r i z e d by intrusive t h o u g h t s a n d by v a r i o u s compulsive, ritualized, a n d stereotyped b e h a v i o u r s like frequent checking a n d hand-washing. E a r l y c o m parisons between obsessive patients a n d anorectic patients indicated a close resemblance in m a n y aspects o f their s y m p t o m a t o l o g y [e.g., 2-4]. Recent reviewers have also conc l u d e d that, in general, there is a high o c c u r r e n c e o f o b s e s s i v e - c o m p u l s i v e d i s o r d e r ( O C D ) s y m p t o m s in e a t i n g disorders, a n d t h a t a n o r e x i a n e r v o s a ( A N ) p a t i e n t s tend
* Department of Psychiatry, The Toronto Hospital. ? Department of Psychiatry, University of Toronto. Graduate Programme in Exercise and Health Science, York University. § Graduate Programme in Psychology, York University. Address correspondence to: Dr. Caroline Davis, 343 Bethune College, York University, 4700 Keele St., North York, Ontario, M3J IP3, Canada. 967
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to have personality traits such as rigidity, restraint in emotional expression, and greater impulse control, which are highly compatible with obsessive-compulsive personality disorder (OCPD)* [6, 7]. However, the extent to which obsessionality is an antecedent, or a consequence, of starvation is less dear. Strober (1980) found that although there was a significant decrease in the extent and severity of symptom obsessionality after weight-restoration, there was no change in the obsessional personality characteristics of AN patients [3]. He suggested, therefore, that these traits may have a facilitating effect on the more general obsessive and compulsive symptoms that emerge during the acute phase of the disorder, particularly in the context of ritualized eating and preoccupations about weight. Others have also concluded that while premorbid obsessional personality traits are, in fact, over-represented in AN patients, the progression of the illness does tend to exacerbate obsessional thoughts and compulsive behaviours [8, 9]. Not only are there clinical similarities between AN and OCD, but there appears to be a neurochemical correspondence. Since interventions that increase intrasynaptic serotonin (5-HT) or directly activate 5-HT receptors tend to reduce food consumption in experimental animals and contribute to obsessive and anxious behaviour in humans, Kaye et al. (1993) propose the theoretical possibility that chronically increased 5-HT activity could be causally implicated in the pathogenesis of both AN and OCD [7]. Indeed, there is good evidence of altered serotonergic function in OCD patients as well as in AN patients [7, 10-12]. Although the mechanism of action is currently unclear, the notion of 5-HT dysregulation is supported by the effectiveness of serotonergic reuptake inhibitors, such as fluoxetine, in the treatment of OCD [e.g., 13, see 14 for a review] as well as in the treatment of AN [see 6 and 7, for reviews]. Hyperactivity is a salient feature of AN and is significant in its link with obsessive compulsiveness. Relentless and excessive exercising has been reported among eatingdisordered patients throughout the history of the disorder [e.g., 15-21]. Traditionally, this behaviour was viewed simply as an analogue of purgation- that is, as a deliberate method of expending unwanted calories. Some have argued, however, that it occupies a more central role in pathogenesis of the disorder [20-24]. Of relevance to these claims is the activity-induced weight-loss syndrome whereby experimental rats with access to a running wheel begin to increase their running when food intake is restricted to 60 to 90 min/day [e.g., 23, 25-28]. Typically, they exhibit decompensated eating behaviour within one week with exponentially increasing activity and decreasing food intake. In the original experiments, the animals literally ran themselves to death! Since the mid-1960s, this robust animal model has been demonstrated in a number of studies, and has subsequently been proposed as a biobehavioural model for AN [20, 24]. Until recently, however, evidence supporting the notion of activity-induced anorexia in the human condition was based solely on anecdote and isolated case reports [e.g., 20, 29]. In a recent clinical study, we found a remarkable similarity with the relationship between activity and starvation in an AN population and the previous reports of activityinduced anorexia in animals [21]. Seventy-five percent of the patient sample reported
* Although OCD and OCPD are frequentlydiscussedinterchangeably,the degreeof comorbiditybetweenthe two syndromes (as definedby DSM-III-R) is relativelysmall(6%), indicatingthat OCPD is not invariablya premorbid condition for the development of OCD [5].
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a n inverse r e l a t i o n s h i p b e t w e e n f o o d i n t a k e a n d degree o f physical a c t i v i t y d u r i n g the acute weight-loss p h a s e o f their disorder. These p a t i e n t s also i n d i c a t e d t h a t their exercising e v e n t u a l l y b e c a m e a c o m p u l s i v e a n d r i t u a l i z e d b e h a v i o u r - an activity t h a t they d e s c r i b e d as "obsessive, .... driven," a n d " o u t o f c o n t r o l . " Recent research suggests t h a t the activity-induced weight-loss b e h a v i o u r p a t t e r n m a y also be a valid a n i m a l m o d e l o f O C D . F o r example, a series o f studies has identified region-specific 5 - H T a b n o r m a l i t i e s in a n i m a l s t h a t were specific to this s y n d r o m e a n d were n o t a general c o n s e q u e n c e o f either weight loss o r exercise a l o n e [27]. A l t e m u s et al. (1993) also f o u n d that, c o m p a r e d to saline- o r i m i p r a m i n e - t r e a t e d rats, rats p r e t r e a t e d with fluoxetine showed a significant a t t e n u a t i o n o f activity, anorexia, a n d weight loss w h e n e x p o s e d to the e x p e r i m e n t a l p r o c e d u r e s d e s c r i b e d a b o v e [26]. Together these studies indicate, indirectly, t h a t exercise a n d starvation, in concert, m a y alter 5 - H T f u n c t i o n i n g a n d e x a c e r b a t e obsessionality. M u c h c o n t r o v e r s y followed the claim, in 1983, t h a t high-level exercising was a n a n a logue o f A N [30]. M o r e recently, Yates has m a d e a strong case, b a s e d o n a wealth o f clinical o b s e r v a t i o n a n d p s y c h o l o g i c a l assessment, t h a t excessive exercisers t y p i c a l l y d i s p l a y a c o m p u l s i v e b e h a v i o u r p a t t e r n a n d are c h a r a c t e r i z e d by an o b s e s s i o n a l a n d rigid p e r s o n a l i t y profile [19]. W h e n o n e considers the t o t a l i t y o f research in this area, there is converging a n d c o m p e l l i n g evidence t h a t physical activity plays a c a t a l y t i c role in the f o r m a t i o n o f a d y n a m i c t r i a d o f related factors (that i n c l u d e obsessive c o m p u l siveness a n d dieting) t h a t feature in the p a t h o g e n e s i s o f e a t i n g disorders. A l t h o u g h there is a small b o d y o f n o n c l i n i c a l research t h a t has d e m o n s t r a t e d an a s s o c i a t i o n between obsessive c o m p u l s i v e n e s s a n d b o t h the frequency [31, 32] a n d the o b l i g a t o r y a n d p a t h o l o g i c a l aspects o f exercising [33], we are unaware o f any research t h a t has s y s t e m a t i c a l l y investigated the r e l a t i o n s h i p between obsessive compulsiveness a n d exercise in clinical samples. T h e present s t u d y was designed, therefore, to investigate these a s s o c i a t i o n s a m o n g eating d i s o r d e r e d patients, as well as to m a k e c o m p a r isons between p a t i e n t s a n d a n o n c l i n i c a l s a m p l e o f exercising w o m e n - b o t h m o d e r a t e exercisers a n d t h o s e w h o are classified as high-level exercisers.
METHOD Subjects Sample 1. Consecutive female patients under the age of 35 who were admitted to the inpatient unit of the Programme for Eating Disorders at The Toronto Hospital over a two and a half year period were considered eligible for assessment. However, for the purposes of this study, only those patients who presented with AN or those who had, within the previous year, satisfied DSM-III-R criteria for AN, were included in the present analyses. Forty-six patients met the inclusion criteria (mean age = 24.2, s = 4.7). Sample 2. As part of a previous investigation of certain psychological aspects of exercising, a large sample of regularly exercising adult men and women were assessed. In order to represent the same age range as the patient sample, only women under the age of 35 were included in the analyses (mean age = 23.3, s = 3.8). This sample was dichotomized according to frequency and duration of exercising. According to a criterion commonly used in previous research, those who were exercising, on average, a minimum of 5 hours per week [e.g., 34, 35] during the year prior to assessment, were classified as "high-level exercisers" (n = 33). The remaining women were classified as "moderate exercisers" (n = 55). Subjects were solicited from the recreation facilities at the university and from a number of health and fitness clubs and YMCAs in the metropolitan Toronto area. Advertisements were posted at these facilities, and notices were put in their newsletters and fliers. Sample 3. Since some aspects of the psychometric data obtained from the patient sample were not available for the subjects in sample 2, a second sample of high-level exercising women, under the age of 35, was used for comparison. These subjects are part of a large on-going prospective exercise study. In order
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to participate in the study, subjects were required to exercise a minimum of 5 hours per week in nonteam activities such as running, cycling, swimming, or weight training. Data from 40 women (mean age = 24.7, s = 3.2) are included in this sample.
Measurements 1. Obsessive compulsiveness was assessed by the "obsessive-compulsive" subscale of the SCL-90 [36]. This dimension reflects symptoms that are closely identified with OCD, such as thoughts, impulses, and actions that are experienced by the individual as unremitting and irresistible, but of an unwanted nature. There are also items that assess more general cognitive difficulty. This measure was obtained only for subjects in samples 1 and 3. 2. Weight Preoccupation was assessed by the Drive-for-Thinness subscale of the Eating Disorder Inventory [37]. 3. Commitment to Exercise was assessed by the 8-item Commitment to Exercise Scale (CES) [33]. A factor-analyses of the items of this scale have identified two moderately correlated factors that assess the obligatory aspects of exercising (e.g., feelings of guilt when an exercise session is missed, adherence to a fixed and set routine for exercising), and the pathological aspects of exercising (e.g., continuing to exercise in the face of illness or injury). 4. Leisure-Time Physical Activity Participation: Using a structured interview format, retrospective data were collected, in samples 1 and 2 for the 12 months immediately preceding the testing session.t The interviewer described a number of physical activities (e.g., jogging/running, swimming, cycling, home exercises, dance classes, etc.), and subjects were asked to indicate those in which they had participated regularly, either for sport or for exercise. They were then asked to specify, within the relevant time frame, the number of weeks of participation per year, the average number of sessions of that activity per week, and the average duration of each session in minutes 0-30, 31-60, 61-90, 90+). Physical activity was quantified by multiplying weeks per year by frequency per week by duration per session in half hour units (1, 2, 3, and 4 consecutively) for each activity and summing across all activities. Therefore, each unit reflects half an hour of activity. For sample 3 the data were collected prospectively over a four-week period. Each subject was given instruction on keeping the physical activity diary, which was identical in format to that used in the structured interview in samples 1 and 2. Subjects summarized their activity at the end of each week and returned the diaries to the experimenters at the end of the study. Physical activity was quantified in the manner described above.:~
Procedure All subjects in sample 1 were tested within the first 5 or 6 weeks of admission to the hospital. All of the psychometric data were obtained as part of an admission package that patients were asked to complete in their spare time. The physical activity data were obtained by means of a personal interview [21]. Subjects in samples 2 and 3 were all tested individually, either at the university laboratory or at an equivalent facility provided at the off-campus locations. First the subjects were asked to complete the questionnaire package, and then the physical activity data were obtained. For the subjects in sample 2 this was done by means of a face-to-face interview. In sample 3, subjects recorded their leisure-time physical activity in weekly diaries and returned them to the investigators at the end of a four-week period. RESULTS
Means, standard deviations, and minima and maxima for all variables are presented in Table I, listed separately by group. A series of one-factor analyses of variance were conducted among the patient group, moderate exercisers, and high-level exercisers from sample 2. Results indicated that
t In some cases, patients had been hospitalized at a different institution at some period during the 12 months that preceded the assessment. In these cases, the physical activity variable was prorated to reflect the period of time the patient was at home and therefore able to exercise. In order to make comparisons with the patient group for whom activity was obtained retrospectively for a 12-month period, the 4-week total for sample 3 was multiplied by 12. We recognize the limitations of extrapolating beyond the data collected, but believe the opportunity to replicate the results obtained with sample 2 outweighs the shortcomings of this calculation.
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OCD, AN, and high-level exercising Table I.-Means, standard deviations, minima, and maxima for all variables listed separately by group Variable
Mean
SD
Min.
Max.
Anorexia nervosa patients (n = 46) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity1 Obsessive compulsive Weight preoccupation
71.7 65.0 75.1 25.5 1.8 15.6
18.9 24.0 18.2 14.4 0.9 5.0
15.2 6.4 16.4 1.0 0.1 2.0
100.0 100.0 100.0 63.0 3.7 21.0
High-level exercisers-Sample 2 (n = 33) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Weight preoccupation
69.3 60.9 70.7 39.2 7.4
13.9 17.8 13.5 4.7 7.1
29.4 25.3 34.2 33.5 0.0
97.7 98.4 96.7 50.3 19.0
21.4 4.9 24.8 13.8 0.0
89.8 96.4 91.4 33.1 20.0
Moderate exercisers (n = 55) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Weight preoccupation
57.9 48.8 61.3 24.5 6.2
14.9 20.4 16.0 4.3 6.2
High-level exercisers-Sample 3 (n = 40) CES (total) CES (Path. subscale) CES (Oblig. subscale) Physical activity Obsessive compulsive Weight preoccupation
71.0 63.8 75.2 32.7 0.7 5.4
17.5 23.5 15.8 9.4 0.5 5. l
37.5 13. l 40.7 20.8 0.0 0.0
100.0 100.0 100.0 56.8 2.3 18.0
A square root transformation was used to normalize the distribution of physical activity scores. The statistics listed in this table for that variable are, therefore, in square root units.
high-level exercisers engaged in more physical activity than the patient group and the moderate exercisers, but there were no differences between the patients and the moderate exercisers. With respect to the CES (both the total score and the subscales), there were no differences between the patients and the high-level exercisers, but both groups had higher scores than the moderate exercisers. Finally, the patients scored significantly higher than both exercise groups on the measure of weight preoccupation. A summary of these findings appears in Table II. The same comparisons were made between the patient group and the high-level exercisers in sample 3, and the results replicated precisely those reported above. In addition, it was found that the patients had significantly higher obsessive-compulsive scores than high-level exercisers. A summary o f these findings is given in Table III. Table IV presents matrices o f all pairwise correlation coefficients among the following variables: obsessive compulsiveness, weight preoccupation, obligatory aspects of exercising, pathological aspects of exercising, and level of physical activity participation. Values are listed separately for the patient group and for high-level exercisers
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C. DAVIS et al. Table II.-Between-Groups (i.e., AN patients, high-level exercisers, and moderate exercisers) analyses of variance for all dependent variables assessed in Samples 1 and 2
Factor
df
SS
F
Post hoc tests*
p
Dependent variable: Physical activity participation Group 2 5440.5 30.47 <0.0001 Error 130 11426.0
HL>AN: HL>ME
Dependent variable: Attitudes to exercise (total) Group 2 5172.4 9.89 <0.0001 Error 126 32956.0
AN>ME:HL>ME
Dependent variable: Attitudes to exercise (Pathology subscale) Group 2 6747.2 7.63 0.0007 AN>ME: HL>ME Error 128 55731.6 Dependent Variable: Attitudes to Exercise (Obligatory subscale) 4744.4 9.08 0.0002 AN>ME: HL>ME Group 2 Error 128 32935.8 Dependent variable: Weight preoccupation Group 2 2160.2 28.79 <0.0001 Error 122 4502.5
AN>HL: AN>RE
* All post hoc comparisons were calculated using Fisher's least-significant difference test. f r o m sample 3. Results indicate that obsessive compulsiveness, weight preoccupation, and pathological attitudes toward exercise are significantly, and positively, related to level o f activity a m o n g A N patients. In addition, obligatory and pathological aspects o f exercising are related to weight preoccupation. In the exercise group, the only significant relationships were a m o n g obsessive compulsiveness and activity level, and between weight preoccupation and obligatory aspects o f exercising. Table III.-Between-groups analyses of variance for all dependent variables in Samples 1 and 3 Factor
df
SS
F
p
Dependent variable: Physical activity participation Group 1 1105.1 7.25 0.0085 Error 84 11426.0
HL>AN
Dependent variable: Attitudes to exercise (total) Group 1 10.6 0.03 0.8589 Error 126 32956.0 Dependent variable: Attitudes to exercise (Pathology subscale) Group 1 27.1 0.05 0.8274 Error 82 46430.2 Dependent variable: Attitudes to exercise (Obligatory subscale) Group 1 0.3 0.00 0.9729 Error 82 24024.0 Dependent variable: Weight preoccupation Group 1 2070.5 82.33 <0.0001 Error 77 4007.0 Dependent variable: Obsessive compulsiveness Group 1 21.0 39.96 <0.0001 Error 77 40.51
AN>HL
AN>HL
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Table IV.-Correlations between variables for female eating disordered patients and high-level exercisers (Sample 3) O-C ~
0
.
2
WP
PA
5 0.40**
WP PA OBL_I_G. PATH.
0.07 ~ ~ . 3 6 " 0.32* --0.07 ~0.30 0.21 0.37" 0 . 1 7 0.11 0.25 0.08 Exercise Group
OBLIG.
PATH.
Patient Group 0.25 0.22 0.40** 0.33* 0.35** ~ _ 0.80*** 0.85***
O-C = Obsessive Compulsiveness. WP = Weight Preoccupation. PA = Frequency and Duration of Exercise. OBLIG = Obligatory Aspects of Exercising. PATH = Pathological Aspects of Exercising. * p < 0.05 ** p < 0.01 *** p < 0.0001. A proposed activity-anorexia model, based, in part, on the interrelationships among these variables, is outlined in Fig. 1 and will be discussed in the following section. DISCUSSION Rothenberg has claimed that AN is a modern variant of obsessive-compulsive syndrome among women in Western c u l t u r e s - a n opinion he based on the obsessional nature o f their concern with food, their extreme perfectionism, and their preoccupation with matters of control [38, 39]. Prompted by the results of the present study and by the various studies linking O C D and AN, we propose a nonrecursive, theoretical model that integrates, in a dynamic sense, obsessive compulsiveness, physical activity, and starvation in the pathogenesis of some eating disorders (see Fig. 1).
IP r o p o s e d ObsessiveCompulslv
Activity - Anorexia ,. --
Pathological ...... to
(
Model I Drlve-for~ hlnness
Physical Activity Level
Fig. 1. A proposed interactive model of anorexia nervosa based on interrelationships among starvation, physical activity, and obsessive compulsiveness.
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Our model shares similarities with that proposed earlier by Epling and Pierce [20, 2 4 ] - specifically, that under-eating and over-exercise become mutually reinforcing behaviours- but extends its scope by taking account of certain salient psychological factors. We suggest that within the context of a sport or fitness environment, the combination of excessive weight preoccupation and obsessive-compulsive tendencies is likely, in women, to increase the frequency and duration of their physical activity and to exacerbate the obligatory nature of their commitment to this behaviour. In turn, increased physical activity itself may foster greater food restriction by virtue of its appetitesuppressing effects [40] and by encouraging a heightened focus on appearance, weight, and performance [29, 41]. Furthermore, strenuous physical activity and food restriction, in concert, have been shown to alter 5-HT functioning [26, 27] and increase obsessionality [e.g., 7, 21] - a factor that then contributes to even greater increases in physical activity and more rigorous starvation. As a consequence, one's commitment to exercise is likely to degenerate into more pathological attitudes and behaviours as obsessionality increases. In summary, we argue that the relationships among physical activity, starvation, and obsessive compulsiveness tend to be reciprocal and dynamic. In other words, together they potentiate one another in a destructive feedback/feedforward loop that becomes self-perpetuating, resistant to change, and may be a significant influence in the development and maintenance of eating disorders for some women. In agreement with previous research [31-33], we also found a positive relationship between obsessive compulsiveness and exercise frequency in high-level exercisers. Importantly, this also maps onto Yates' (1991) claim that excessive exercising and eating disorders are "sister activities," and strongly related to obsessionality [19]. Nevertheless, although the CES scores of high-level exercisers were as high as patients' scores, the former had, on average, significantly lower scores on obsessive compulsiveness and weight preoccupation. When, we might ask, are high-level exercisers at risk of developing AN? We suggest that assiduous and strenuous exercising is potentially problematic in an individual who is both highly weight preoccupied and characterised by a perfectionistic and obsessive-compulsive personality. As an example, a post hoc inspection of the individual scores for the high-level exercisers in sample 3 identified one (and only one woman [i.e., 2.5 °70of the group]) who scored above the group m e a n - and in this case, in excess of one standard deviation above on all the relevant variables: obsessive compulsiveness, weight preoccupation, the CES subscales, and physical activity level. She also had a relatively low Body Mass Index of 19.1. We suggest that this particular constellation of characteristics may well indicate a subclinical case of AN or, at the very least, a vulnerable premorbid condition that is in danger of developing into the full-blown syndrome. Finally, results of this study also supported the construct validity of the Commitment to Exercise Scale (CES)-- an inventory designed to assess the core features characteristic of those who exercise excessively [33]. For example, high-level exercisers and anorectic patients were not different from each other, but both scored higher than moderate exercisers on both factors of the CES§. In addition, correlational analyses revealed § These findings were also replicated when comparisons were made between AN patients and high-level exercisers from sample 3.
OCD, AN, and high-level exercising
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a significant relationship between weight preoccupation and the obligatory aspects of exercising for high-level exercisers and for AN patients; however, only in the AN group was weight preoccupation related to pathological exercising, which, in turn, was related to level of exercising. Taken together, these findings are in accord with clinical reports that typically describe the relentless, compulsive, and excessive nature of the physical activity observed among AN patients [21, 42, 43]. In conclusion, it is important to emphasize that the aetiology of eating disorders is highly complex and, indeed, variable across cases. For these reasons, we acknowledge that our proposed activity-anorexia model may explain one aspect of the pathogenesis of AN and then only for some individuals. Clearly, this model says little about the motivations that initially trigger exaggerated weight and diet concerns in women, nor does it address the myriad of factors that predispose certain individuals, and not others, to become heavily invested in athletics and exercise.
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