Comorbidity of Binge Eating Disorder and the Partial Binge Eating Syndrome with

Bipolar Disorder

Stephanie Kruger Gerald Shugar

Robert G . Cooke (Accepted 5 December 1994)

Objective: The authors examined the prevalence of binge eating disorder (BED), partial binge eating syndrome, and night binge eating syndrome in subjects with bipolar disorder (BD). Method: Sixty-one subjects in whom BD was established using DSM-Ill-R criteria received a semistructured clinical interview including a detailed description of binge eating behavior and of night binge eating. Frequencies were compared to prev- alence estimates in community samples. Results: €ight subjects (13%) met DSM-IV criteria for the diagnosis of -B€D. An additional 'I5 subjects (25%) exhibited a partial binge eating syndrome. These two otherwise identical groups of binge eaters were separated only by the DSM-1V frequency criterion. The rates found were higher than rates found in community sampies. Ten subjects reported night binge eating in addi- tion to their usual binge eating behavior. This occurred consistently between 2:OO and 4:OO a.m. Conclusions: Possible underlying mechanisms for the high frequency of binge eating among bipolar subjects are discussed including a model of serotonin-mediated self-modulation of mood. The finding of two groups of binge eaters separated only by the frequency criterion raises questions as to whether the frequency criterion as pres- ently defined in DSM-IV is valid or should be modified. Q 1996 by john Wiley & Sons, Inc.

Recently, binge eating disorder (BED) has been described to account for a group of people who suffer from recurrent binge eating, but who do not regularly engage in the compensatory behaviors to avoid weight gain that are seen in bulimia nervosa as de- scribed in the Diagnostic and statistical manual of mental disorders, 4th ed. (DSM-IV; Amer-

Stephanie Kruger, M.D., is Fellow in Psychiatry, Westfalisches Zentrum fur Psychiatrie, University of Bochum, Germany and visiting Fellow, Bipolar Disorders Clinic, Clarke Institute of Psychiatry, Toronto, Canada. Gerald Shugar, M.D., i s Associate Professor, Department of Psychiatry, University of Toronto, and Staff Psychiatrist, General Psychiatry Division, Clarke Institute of Psychiatry. Robert G. Cooke, M.D., is Assistant Professor, Department of Psychiatry, University of Toronto and Staff Psychiatrist, Bipolar Disorders Clinic, Clarke Institute of Psychiatry. Address reprint requests to Dr. Krugerat Westfaiisches Zentrum fur Psychiatrie, Aiexandrinenstr. ? 44791, Bochum, Germany.

International journal of Eating Disorders, Vol. 19, No, 1 , 45-52 (1996) Q 1996 by John Wiley & Sons, Inc. CCC 0276-3478/%/0100458

46 Kruger, Shugar, and Cooke

ican Psychiatric Association, 1994). The results of two multisite field trials suggest that the prevalence of BED in the general population ranges from 2.0% to 4.6% (Spitzer, Yanovski, Wadden, & Wing, 1992; Spitzer et al., 1993).

Reports on the sex distribution of BED vary between an equal gender distribution (Spitzer et al., 1993) to a femalelmale ratio of 3:l (Spitzer et al., 1992).

There is a growing body of literature suggesting that the comorbidity of BED with major psychiatric disorders, particularly mood disorders, is high. Marcus et al. (1990) found that obese binge eaters were twice as likely as obese subjects without BED to meet criteria for one or more psychiatric disorders. They were especially more likely to have a lifetime diagnosis of major depression (32% vs. 8%). These findings have been con- firmed in other reports: Yanovski et al. (1992) reported a lifetime prevalence of major depression of 5196, Spitzer et al. (1993) of 46.4%, and de Zwaan, Nutzinger, and Schoen- beck (1993) of 54.5%. The prevalence rate of major depression in subjects with BED has also been reported to be higher than in the general population (16.7%), but lower than in bulimic subjects (73.3%) (Spitzer et al., 1993).

The comorbidity of BED and bipolar disorder (BD) has not been thoroughly investi- gated. Among their 43 obese subjects with BED, Yanovski, Nelson, Dubbert, and Spitzer (1993) found one subject with a history of BD. Conversely, the prevalence of BED in patients with BD has not been established. Accordingly, the present study attempts to provide more systematic data on this association.

METHOD

The study was conducted in the Bipolar Disorders Clinic of the Clarke Institute of Psychiatry, a tertiary acute and chronic care psychiatric facility affiliated with the Uni- versity of Toronto. Sixty-one consecutive euthymic outpatients attending appointments in the clinic were asked to participate in the study. Subjects were approached for the study by one of the authors (S.K.) and all gave informed consent. All had previously received a diagnostic interview by an experienced clinician to establish BD according to the Diagnostic and statistical manual of mental disorders, 3rd Rev. ed. (DSM-111-R; American Psychiatric Association, 1987) criteria and 38 had also received a standardized interview, the Schedule for Affective Disorders and Schizophrenia (SADS) as part of the diagnostic assessment (Spitzer & Endicott, 1978). The diagnosis of BED by DSM-IV criteria (Spitzer et al., 1993) was established during a semistructured clinical interview, conducted by one of the authors (S.K.). To ensure correct identification of binge episodes and to distinguish subjective from objective binge eating (Marcus, Smith, Santellini, & Kaye, 1992), a detailed description of the binge eating behavior was obtained from each sub- ject. The frequencies were compared to the highest prevalence estimates for BED in a community sample (Spitzer et al., 1993). Relevant information about each subject’s bipolar illness was obtained from the attending psychiatrist, the medical record, the semistructured clinical interview, and from the SADS interview where available. Differ- ences in prevalence were tested for significance at p < .05 by chi-square analysis.

RESULTS

Subjects The sample comprised 38 women and 23 men. Forty-three had been diagnosed with

BD (BD I) and 18 with BD not otherwise specified (BD 11). The mean age was 39.6 (211.6

Binge Eating Disorder 47

SD) years. The mean age at onset of the bipolar illness was 25.5 (k7.4 SD) years, and the mean duration of the BD was 14.2 (k8.7 SD) years. The mean body mass index (BMI, kg/m2) was 26.8 (56.0 SD, range 18.7 to 34.0) for females and 29.2 (54.2 SD, range 21.8 to 32.6) for males.

All subjects were receiving treatment with either lithium, carbamazepine, or val- proate, or a combination of these mood stabilizing agents. Seven subjects were also on maintenance serotonin reuptake inhibitors, 6 on maintenance tricyclics, 9 were receiving neuroleptics, and 28 were receiving other agents such as benzodiazepines or L-thyrox- ine.

Binge Eating and BED

Table 1 lists the DSM-IV criteria for BED and the frequency with which they were endorsed.

Twenty-three subjects fulfilled criteria A, B, C, and E. Eight of these met criterion D, the frequency criterion. The remaining 15 subjects reported binge eating from twice weekly to once every 2 weeks for periods of from 3 months to 6 months (see Table 2).

Thus, the total sample of binge eaters can be separated into two groups, one that met diagnostic criteria for BED and another that exhibited all features of BED but fell short of the frequency criterion.

Neither the group of 8 subjects with BED nor the remaining 15 subjects with binge eating symptoms differed significantly from the rest of the study sample or from each other with regard to mean age, sex, affective subtype (BD I, BD 11), age at onset of the affective disorder, or type of maintenance therapy.

The prevalence rate of BED in our sample was 13% (8 of 61 subjects), which is sig- nificantly higher than the prevalence rate in the community (up to 4.6%) (x2 = 8.084, df = 1, p < .Ol). The onset of BED preceded the onset of BD in all subjects: The mean age of onset of BED was 18 (k3.4 SD) years, antedating the average onset of the affective disorder by approximately 7 years.

Table 1. the symptoms

Diagnostic criteria for binge eating disorder and number of subjects endorsing

A. n = 23 Recurrent episodes of binge eating, an episode being characterized by both of the following: (1) Eating, in a discrete period of time (e.g., within any 2-hr period), an amount of food that is definitely

(2) A sense of lack of control during the episodes, for example, a feeling that one can’t stop eating or

B. n = 23 During most binge episodes, at least three of the following: (1) Eating much more rapidly than usual. (2) Eating until feeling uncomfortably full. (3) Eating large amounts of food when not feeling physically hungry. (4) Eating alone because of being embarrassed by how much one is eating. (5) Feeling disgusted with oneself, depressed, or feeling very guilty after overeating. C . n = 23 Marked distress regarding binge eating. D . n = 8 The binge eating occurs, on average, at least 2 days a week for a 6-month period. E. n = 23 Does not occur only during the course of bulimia nervosa or anorexia nervosa.

larger than most people would eat during a similar period of time in similar circumstances.

control what or how much one i s eating.

48

Table 2. Frequency of binge eating among subjects with partial binge eating syndrome (n = 15)

Kruger, Shugar, and Cooke

Frequency

Duration Once Every More than (Months) 2 Weeks Once a Week Once a Week

3 1 2 4 3 5 1 2 6 6

As shown in Table 3, subjects with binge eating symptoms and subjects with BED overlapped in their binge eating patterns.

Seven of the 8 subjects with BED binged during the depressive phase and also during the symptom-free interval, and 1 subject binged only when depressed. Among the 15 subjects with binge eating symptoms, 6 binged during both depressed and euthymic phases and 4 binged only when depressed. However, unlike the BED subjects, 5 binged exclusively during the symptom-free interval. The relatively small number of subjects in our study does not permit us to conclude whether this is a significant variation exclusive to this group. None of the subjects in either group reported binge eating during the manic or hypomanic phase.

Two subjects with BED and 4 with binge eating symptoms described a substantial increase in appetite and weight on lithium therapy and 1 subject with BED described increased craving for sweets and increased weight on nortriptyline; however, neither

Table 3. (n = 15) and of subjects with binge eating disorder (BED) (n = 8)

Characteristics of subjects with partial binge eating syndrome

Subjects with Partial Binge

Eating Syndrome Subjects with BED

Sex

Age (year)” Body mass index (kg/m)”

Age at onset of bipolar disorder (BD)” Age at onset of binge eating” BD I BD I1 Depression binging Interval binging Depression and interval binging Night binging syndrome Medication

a) Lithium b) Valproate c) TCA d) Neuroleptics e) Others

f 12 m 3

38.7 ? 6.2 f 31.2 4 4.1

m 29.5 rt 3.3 27.3 2 2.4 18.6 ? 3.8

11 4 4 5 6 6

15 7 1 4

14

f 6 m 2

39.8 2 6.4 f 36.7 2 4.1

m 33.5 -C 3.8 25.6 2 3.4 18.8 2 3.4

7 I 1 0 7 4

8 5 1 0 7

”M ? SD.

Binge Eating Disorder 49

these nor any of the other subjects reported a medication-related induction or worsening of binge eating.

Four subjects with BED (3 females, 1 male) and 6 subjects with binge eating symptoms (4 females, 2 males) reported night binging in addition to their usual binge eating pattern. It occurred regularly two to six nights a week and did not vary across weekdays, weekends, or vacations.

These subjects reported waking up between 2:OO and 4:OO a.m. with the urge to binge. They did binge whenever it was possible, and when the need for this behavior could not be satisfied, insomnia, anxiety, and restlessness resulted. Subjects also reported various countermeasures to stop this behavior, like locking the kitchen door and hiding the key or emptying the fridge before going to bed. During their night binges subjects reported eating indiscriminately whatever they could find including unusual and inappropriate food combinations.

DISCUSSION

To our knowledge this is the first study on the comorbidity of BD and BED. It estab- lishes a significantly higher prevalence (13%) than in the general population. These findings are even more striking if we also include 15 subjects with binge eating behavior, who fall short of the frequency criterion (partial syndrome). Combined, 38% of the BD sample exhibit significant binge eating behavior including loss of control during a binge and marked distress regarding this behavior. In a Canadian community sample, Garfinkel et al. (in press) established a prevalence rate of 7.5% for recurrent binge eating behavior using the World Health Organization International Diagnostic Interview crite- ria which include subjects with BED in the group of recurrent binge eaters. The preva- lence rate of 38% identified in the current study is five times greater than the community sample rate.

All subjects with BED binged during the depressive phase of their illness, and 10 of 15 subjects with the partial syndrome reported this behavior during their depressive epi- sodes. None binged while manic. This raises questions as to whether binging serves a particular purpose in subjects with BD. There is substantial evidence that mood and eating behavior are closely related via central serotonergic pathways (Rosenthal, Gen- hart, Jacobsen, Skwerer, & Wehr 1987; Schuman, Gitlin, & Fairbanks, 1987; Krauchi, Wirz-Justice, & Graw, 1990; Brzezinski et al., 1990; Moller, 1992). It has also been sug- gested that an underlying serotonin deficiency is responsible for carbohydrate craving, which may subsequently facilitate serotonin synthesis in the brain (Moller, 1992). Fur- thermore, there is evidence that excessive carbohydrate intake temporarily relieves de- pressive symptoms via increased neuronal serotonergic activity and thus may represent a form of self-medication (Schuman et al., 1987; Moller, 1992). Applying this model to the binge eating patterns of our subjects with BD, it may be that binge eating serves as a compensatory behavior during subjects’ depressed episodes, modulating their mood.

While the serotonin model may help to explain binge eating, there is additional evi- dence that obesity induced by excess carbohydrate intake may be responsible for the recurrent nature of this behavior in subjects with BD. Obese food cravers have been found to experience a clinical amelioration in depressed mood after consumption of carbohydrates, leading them to repeatedly overeat whereas lean subjects experience sleepiness and fatigue and deterioration in mood (Lieberman, Wurtman, & Chew, 1986; Spring, Maller, Wurtman, Digman, & Cozolino, 19821983). These observations are con-

Kruger, Shugar, and Cooke 50

sistent with findings of a high prevalence of depressive symptomatology in obese bin- gers (Marcus, Wing, & Hopkins, 1988; Spitzer et al., 1992; de Zwaan et al., 1993) and are supported by a report from de Zwaan et al. (1993) who found that the most favored binge foods are rich in carbohydrates and predominantly include sweets, bread, and pasta. Yanovski et al. (1992) reported that obese binge eaters were more likely to overeat on carbohydrate-rich foods than obese nonbingers. These findings are relevant to our patient population because the BMI values for subjects with BED and with partial binge eating syndrome indicated moderate obesity.

The reports described above are all consistent with a theory of self-modulation of mood via carbohydrate binge eating. However, two recent small studies have suggested that pharmacotherapy with the serotonin-reuptake inhibitors fluvoxamine and fluoxet- ine may not improve the binge eating behavior in overweight depressed binge eaters, suggesting the involvement of additional mechanisms in the pathogenesis of binge eating (Marcus et al., 1990; de Zwaan et al. 1993). Furthermore if binge eating and mood states are related, then the frequent occurrence of this behavior during the symptom-free interval needs further explanation. One possibility is that binge eating coincides with minor mood fluctuations during interepisodic intervals. Another is that it simply reflects the persistence of a habit pattern generated during the depressive phase.

Ten subjects reported night binging in addition to their usual binge eating behavior. The night binging syndrome was first described by Stunkard, Grace, and Wolf (1955), and only nine reports of this syndrome were published over the subsequent 36 years, most being single case studies (Schenck & Mahowald, 1994). Recently three systematic studies (Schenck, Hurwitz, Bundlie, & Mahowald, 1991; Schenck, Hurwitz, OConnor, & Mahowald, 1994) have confirmed its existence. Night binging syndrome is different from the late evening binge peak reported by obese binge eaters and bulimics (Mitchell, Hatsukami, & Pyle, 1985; de Zwaan et al., 1993) in that it occurs after a few hours of normal sleep and is accompanied by varying stages of consciousness, with near auto- matic entry into the kitchen and rapid indiscriminate consumption of food (Schenck & Mahowald, 1994).

The current study is the first to describe the consistent occurrence of night binging syndrome between 2:OO and 4:OO a.m. This may be of significance in the bipolar popu- lation because the early morning hours are also the time in which mood switches are reported to occur in subjects with BD (Bunney, Dennis, Goodwin, & Borge, 1972).

Our findings add to the controversy surrounding the validity of BED as currently defined (Spitzer et al., 1993; Fairburn, Welsh, & Hay, 1993; Pincus, Frances, Davis, First, & Widiger, 1992; Fichter, Quadflieg, & Brandl, 1993): Of the 23 subjects with partial binge eating syndrome, only 8 (35%) fulfilled the required time criterion of at least two binge episodes per week for a 6-month period. This makes the frequency criterion the distinguishing factor between the "true" binge eaters and the group with the partial syndrome. The latter exhibits all the behavioral features of BED but falls short of the frequency criterion by binging 3 to 6 months from twice per week to once per 2 weeks.

The frequency criterion has been the subject of controversial discussion (Fairburn et al., 1993; Spitzer et al., 1993), with opinions suggesting that too few investigators have collected data on binge frequencies lower than twice a week for 6 months (Spitzer et al., 1993). Our data support the suggestion by Spitzer et al. (1993) that the frequency crite- rion for BED needs to be revised in further studies to arrive at valid recommendations for the minimal frequency of binge episodes.

Many authors agree (de Zwaan et al., 1993; Devlin, Walsh, Spitzer, & Hasin, 1992; Fichter et al., 1993) that there is a definite need for developing useful diagnostic cate-

Binge Eating Disorder 51

gories by redefining the eating disorders not otherwise specified (EDNOS). To ensure that the diagnostic criteria for BED do not comprise a heterogenous group, and to confirm its validity as a separate nosological entity in DSM-IV, research should focus on aspects of comorbidity, distinguishing binge eaters from nonbinge eaters and on binge eating behavior in other psychiatric disorders.

REFERENCES

American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders (3rd Rev. ed.). Washington, DC: Author.

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Wash- ington, DC: Author.

Brzezinski, A. A., Wurtman, J . J . , Wurtman, R. 1.. Gleason, J. , Greenfield, J., & Nader, T. (1990). D-fenflu- ramine suppresses the increased caloric and carbohydrate intakes and improves the mood of women with premenstrual depression. Obstetrics and Gynecology, 76, 296-301.

Bunney, W. E., Dennis, M. L., Goodwin, F. K., & Borge, G. F. (1972). The “switch process” in manic- depressive illness. Archives of General Psychiatry, 27, 295-302.

Devlin, M. J., Walsh, T. B., Spitzer, R. L., & Hasin, D. (1992). 1s there another binge eating disorders? A review of the literature on overeating in the absence of bulimia nervosa. International journal of Eating Disorders, 1 1 , 333-340.

de Zwaan, M., Nutzinger, D. O., & Schoenbeck, G. (1993). Binge eating in overweight women. Comprehensive Psychiatry, 33, 256-261.

Fairburn, C. G., Welsh, S. L., & Hay, P. J . (1993). The classification of recurrent overeating: The ”binge eating disorder” proposal. lnternationul journal of Eating Disorders, 13, 155-159.

Fichter, M., Quadflieg, N., & Brandl, B. (1993). Recurrent overeating: An empirical comparison of binge eating disorder, bulimia nervosa, and obesity. International journal of Eating Disorders, 14, 1-16.

Garfinkel, P. E., Lin, E. L., Goering, P., Spegg, C., Goldbloom, D. S., Kennedy, S. H., Kaplan, A,, &Wood- side, B. Bulimia nervosa in a community sample. Prevalence, comorbidity and psychosocial functioning. American journal of Psychiatry (in press).

Krauchi, K., & Wirz-Justice, A. (1988). The four seasons: Food intake frequency in seasonal affective disorder in the course of the year. Psychiatry Research, 25, 323-338.

Krauchi, K., Wirz-Justice, A., & Graw, P. (1990). The relationship of affective state to dietary preference: Winter depression and light therapy as a model. journal of Affective Disorders, 20, 43-53.

Lieberman, H. R., Wurtman, 1. J., & Chew, 8. (1986). Changes in mood after carbohydrate consumption among obese individuals. American journal of Clinical Nutrition, 44, 772-778.

Loro, A. D., & Orleans, C. S. (1981). Binge eating in obesity: Preliminary findings and guidelines. Addictive Behavior, 7, 47-55.

Marcus, M. D., Smith, D., Santellini, R., & Kaye, W. (1992). Characteristics of eating disordered behavior in obese binge eaters. lnternutionul journal of Eating Disorders, 3, 249-255.

Marcus, M. D., Wing, R. R., Ewing, L., Kern, E., Gooding, W., & Mc Dermot, M. (1990). Psychiatric disorders among obese binge eaters. lnternationul journal of Eating Disorders, 9, 67-77.

Marcus, M. D., Wing, R. R., & Hopkins, J . (1988). Obese binge eaters: Affect, cognitions, and response to behavioral weight control. Iourtial of Consulting Clinical Psychology, 3, 433439.

Marcus, M. D., Wing, R. R., & Lamparski, D. M. (1985). Binge eating and dietary restraint in obese patients. Addictive Behavior, 10, 163-168.

Mitchell, J . E., Hatsukami, D., & Pyle, R. L. (1985). Characteristics of 275 patients with bulimia. American journal of Psychiatry, 142, 482-485.

Moller, S. E. (1992). Serotonin, carbohydrates and atypical depression. Pharmacology and Toxicology, 71(Suppl.),

Pincus, H. A., Frances, A,, Davis, W. W., First, M. B., & Widiger, T. A. (1992). DSM-IV and new diagnostic categories: Holding the line on proliferation. American Iournal of Psychiatry, 149, 112-117.

Rosenthal, N. E., Genhart, M., Jacobsen, F. M., Skwerer, R. G., & Wehr, T. A. (1987). Disturbances of ap- petite and weight regulation in seasonal affective disorder. Annals of the New York Academy of Science, 499, 216-230.

Schenck, C. H., Hurwitz, T. D., Bundlie, S. R., & Mahowald, M. W. (1991). Sleep related eating disorders: Polysomnographic correlates of a heterogenous syndrome distinct from daytime eating disorders. Sleep, 14, 419431.

Schenck, C. H., Hurwitz, T. D., OConnor, K. H., & Mahowald, M. W. (1993). Physical, sexual and/or emo- tional abuse reported by 37% of 125 consecutive adult patients presenting clinically to a sleep disorders center. Sleep Research, 22, 256 (abstract).

61-71.

Kruger, Shugar, and Cooke 52

Schenck, C . H., & Mahowald, M. W. (1994). Review of nocturnal sleep-related eating disorders. lntertlational Journal of Eating Disorders, 4, 343-356.

Schuman, M., Gitlin, M. J., & Fairbanks, L. (1987). Sweets, chocolate and atypical depressive states. Journal of Nervous and Mental Disorders, 175, 491-495.

Spitzer, R. L., & Endicott, J . (1978). Schedule for Affective Disorders and Schizophrenia. New York: Biometncs Research, Evaluation Section, New York State Psychiatric Institute.

Spitzer, R. L., Stunkard, A., Yanovski, A., Marcus, M., Wadden, T., Wing, R., Mitchell, J., & Hasin, D. (1993). Binge eating disorder should be included in DSM-IV. A reply to Fairburn et al.'s "The classification of recurrent overeating: The binge eating disorder proposal." lnternntional Journal of Eating Disorders, 13,

Spitzer, R. L., Yanovski, S., Wadden, T., & Wing, R. (1992). Binge eating disorder: Its further validation in a multisite study. lnternntionnl Journal of Eating Disorders, 13, 137-153.

Spring, B., Maller, O., Wurtman, J., Digman, L., & Cozolino, L. (1982/1983). Effects of protein and carbohy- drate meals on mood and performance: Interactions with sex and age. Journal of Psychiatric Research, 17, 155-167.

Stunkard, A. J., Grace, W. J., &Wolf, H. (1955). The night-eating syndrome: A pattern of food intake among certain obese patients. American Journal of Medicine, 19, 78-86.

Yanovski, S. Z., Leet, M., Yanovski, J. A., Flood, M., Gold, P. W., Kissileff, H. R., & Walsh, 8. T. (1992). Food selection and intake of obese women with binge eating disorders. American Journal of Clinical Nutrition, 56, 975-980.

Yanovski, S. Z., Nelson, J. E., Dubbert, B. K., & Spitzer, R. L. (1993). Association of binge eating disorder and psychiatric comorbidity in obese subjects. American Journal of Psychiatry, 150, 1472-1479.

161-169.