- Email: [email protected]
A controlled study of alexithymia in eating disorders
A Controlled
Study of Alexithymia Ulrike Schmidt,
Arif Jiwany,
The aims of the study were (1) to establish whether alexithymia is present in patients with bulimia nervosa (BN), (2) to compare bulimic patients with restricting anorexics (AN/R), bulimic anorexics (AN/BN), and normal controls with regard to alexithymia, (3) to determine whether in BN patients alexithymia is a state or a trait, and (4) to see whether alexithymia predicts short-term treatment outcome in BN. Study 1 included 173 eating disorder patients (BN: n = 93, AN/R: n = 55, AN/BN: n = 25) who were compared with 95 controls on the Toronto Alexithymia Scale (TAS). Study 2 included 41 BN patients who were assessed prospectively with the TAS before and after a
A
LEXITHYMIA was first used to describe a personality trait characteristic of psychosomatic patients,’ but has since been applied to patients across a wide range of psychological disorders.* Alexithymia denotes an inability to experience and express emotions and to discriminate between emotional states and bodily sensations. Alexithymic individuals are said to be concrete in speech and thought and to have an impoverished fantasy life.3 Alexithymia has also been conceptualized as a defense mechanism against emotional distress and pain in substance abusers4 and patients with severe physical illness.5 It has been argued that anorexia nervosa is a paradigm of psychosomatic illness.6 The Interoceptive Awareness Subscale of the Eating Disorder Inventory’ has some overlap with the alexithymia construct, and anorexic and bulimic patients score abnormally on it compared with non-eating-disordered control subjects. Several studies have measured alexithymia in anorexic patients, albeit with different methods and conflicting results. 8-11On the Toronto Alexithymia Scale (TAS),12 anorexic patients were more alexithymic than normal controls,” whereas when alexithymia was assessed on speech samples, anorexic patients were less alexithymic than surgical inpatients.‘O In a study using some
From the Institute of Psychiatry and Maudsley Hospital, London; and the University College Hospital and Middlesex Hospital Medical School, London, England. Address reprint requests to Ulrike Schmidt, M.D., Institute of Psychiatry, De Crespigny Park, London SE5 8AZ, England. Copyright 0 1993 by W.B. Saunders Company 0010-440x/93/3304-0018$03.00/0
54
in Eating
Disorders
and Janet Treasure lo-week drug treatment. AN/R patients in study 1 had significantly higher alexithymia scores than BN patients. All three eating disorder groups had significantly higher alexithymia scores than controls. For BN patients in study 2, TAS scores before and after drug treatment were stable, despite significant symptomatic improvement. We conclude the following: (1) eating disorder patients are considerably more alexithymic than normal controls; and (2) in BN, alexithymia may be a trait, unaffected by clinical improvement unless psychological treatment, encouraging the expression of emotions is offered. Copyright 0 1993 by W.B. Saunders Company
Rorschach indices and the Minnesota Multiphasic Personality Inventory (MMPI), anorexia nervosa patients did not differ from neurotic controls.9 One study8 found alexithymia to increase with weight restoration, whereas two other studies found no such link.9J1 Patients with bulimia nervosa often respond to stress by bingeing and vomiting, but find it difficult to make a link between their behavior and emotional triggers.13 This suggests that alexithymia might play a role in the psychopathology of these patients; however, this hypothesis has not yet been tested. The aims of the study presented here were (1) to establish whether alexithymia is present in patients with bulimia nervosa, (2) to compare bulimic patients with restricting anorexics, bulimic anorexics, and normal controls with regard to alexithymia, (3) to determine whether in bulimia nervosa patients alexithyrnia is a state or a trait, and (4) to see whether alexithymia predicts short-term treatment outcome in bulimia nervosa. METHOD To answer the above questions, two studies were conducted, one cross-sectional (study 1) and the other prospective (study 2).
Study 1 A consecutive series of patients referred to the Maudsley Hospital Eating Disorder Clinic were sent the following questionnaires before their first appointment: (1) The TAS, is a 26-item self-rating questionnaire, following a likert format. The TAS is a reliable and valid measure of the alexithymia construct,14 and is superior to other measures of alexithymia.15 In nonpatient populations, scores are not associated with age, education, or socioeconomic status.16
Comprehensive
Psychiatry, Vol. 34, No. 1 (January/February),
1993: pp 54-59
ALEXITHYMIA
55
IN EATING DISORDERS
The maximum score is 130. In accordance with previous studies, a score of 74 or greater on the TAS was chosen as the cut-off point for alexithymia.‘4J5 (2) The Bulimic Investigatory Test, Edinburgh (BITE),” is a 33-item self-rating instrument that measures bulimic symptomatology. It consists of a symptom scale (maximum score. 30; a score of 20 or more indicates highly disordered eating and the presence of binge eating) and a severity scale (maximum score, 33; a score of 5 or above is considered clinically significant). (3) The Body Shape Questionnaire (BSQ)‘s is a 34-item questionnaire designed to measure body shape concerns in eating disorder patients. The maximum score is 204. Only those patients of the series who at their first clinical assessment fulfilled DSM-III-R criteria for bulimia nervosa (BN) or anorexia nervosa were included in this study. Patients with anorexia nervosa were subdivided into those with restricting anorexia nervosa (AN/R) and those with a bulimic subtype (ANIBN), as there is growing evidence that these two groups differ from each other in a number of ways, including their psychopathological concomitants.” Patients with obesity, eating disorder not otherwise specified, or other main diagnoses were excluded from the sample. The TAS was also given to a control group of university students. Socioeconomic status was determined by the Hollingshead two-factor method and was based on father’s occupation.Z0
Study 2 Forty-one BN patients who took part in a IO-week drug treatment study (2 weeks single-blind placebo wash-out followed by 8 weeks double-blind placebo-controlled fluvoxamine) were studied prospectively. These patients were a subgroup of the total sample, which simply comprised those bulimic patients who had been referred since October 1989, when the drug study was started. They were given the TAS, the BITE, the BSQ, the Hamilton Depression (HAM-D) scale?’ and an interviewer-rated assessment of binge and vomit frequency before and after treatment.
Stu t&tics Data were analyzed using SPSS-PC+.2” The groups were compared using analysis of variance (ANOVA). Duncan’s multiple-range tests were performed, to reduce the type I
Table 1. Sociodemographic
Sex (n) Mean age 2 SD (yr)
error rate, which is inflated when many comparisons are performed.‘3 Ninety-five percent confidence intervals (CI) for the means of samples or differences between means are presented where appropriate.Z3 Kendall’s 7-b was calculated for within-group correlations. Wilcoxon’s matched-pairs signed-ranks test was used to compare changes within groups over time and treatment.
RESULTS
Study 1 Sample characteristics. One hundred seventy three female eating disorder patients were included in the study: 93 had BN, 55 had AN/R, and 25 had AN/BN. The control group comprised 48 female and 47 male students. Table 1 shows the age and class distribution of eating disorder patients and controls and gives information on body mass index (BMI = weight/ height2) and eating symptomatology of eating disorder patients. Eating disorder patients and controls were comparable in social class; however, the control group was younger than the clinical groups (ANOVA: F ratio = 4.56, F probability = .OOl). As expected, patients with BN were of normal weight, whereas AN/R and AN/BN subjects were both underweight. Patients with bulimic disorders had BITE symptom and severity scores and BSQ scores comparable to other bulimic samples,17~18whereas AN/R subjects-as expected-had lower scores. Alexithymia. Table 2 shows the means, standard deviations, and ranges of TAS scores. ANOVA showed a significant group effect (F ratio = 10.9, F probability = .OOl). Patients with AN/R had significantly higher scores than patients with BN, and all three eating disorder
Characteristics of Patients and Controls and Patients’ Eating Pathology
BN
AN/R
F (93) 23.8 + 5.1
F (55) 23.6 + 5.7
ANiBN
Controls
F (25) 22.4 k 5.9
F (48) 21.0 + 3.0
M 147) 21.2 k 2.5 71%
Social class High
58%
56%
54%
72%
Middle
28%
33%
27%
19%
1 1%
Low
14%
1 1%
18%
9%
18%
BMl* t SD
21.3 + 2.6
15.8 + 2.3
17.6 k 2.0
BITE symptomt k SD
25.8 + 3.0
13.5 k 7.3
21.4 + 6.3
BITE severity t SD BSQ* 2 SD
13.3 + 4.7 148.1 f 27.5
4.2 k 5.3 105.3 k 36.5
10.4 k 6.8 137.5 2 43.7
*Body mass index: This was not calculated for three patients with a bulimic disorder and three patients with restricting anorexia nervosa, as patients’ heights had been omitted from the case notes. tBlTE and SBSQ: Not all eating disorder patients were given these two questionnaires in addition to the TAS (BITE: BN, n = 87; AN-R, n = 30; AN/BN, n = 14. BSQ: BN, n = 83; AN/R, n = 28; AN/BN, n = 13).
56
SCHMIDT, JIWANV, AND TREASURE
Table 2. TAS: Means, Standard Deviations, 95% Confidence Intervals of Means, and Ranges
Mean(SD)
Cl (95%)
BN
93
72.4 (10.9)
70.2-74.6
41-98
AN/R
55
76.5 (12.8)
73.1-79.9
46-124
AN/EN
25
74.2 (13.1)
68.8-79.6
52-102
Female students
48
66.8 (9.3)
64.1-69.5
46-84
Male students
47
63.6 (11.2)
60.3-66.9
42-90
”
Range
NOTE. Significant group effect by ANOVA (F ratio = 10.9, F probability = ,001). Duncan’s range test: AN/R Y BN and AN/R, AN/BN, BN v male and female control patients are all significant at the .05 level.
groups differed from female and male controls (Duncan’s range test). In the bulimic group, 46 (50%) scored above the cut-off point for alexithymia; in the restricter group, 31 (56%); and in the mixed AN/BN group, 12 (48%). This contrasted with 13 (27%) and 9 (19%) in female and male controls. This difference was significant (x2 test: df = 4, P = .0002). Correlation matrices for TAS, BMI, BITE, and BSQ were calculated for each of the eating disorder groups using Kendall’s 7-b. The TAS did not correlate with any of these variables in any of the three groups. Study 2 Sample characteristics. The 41 patients who took part in the drug-treatment study were very similar to the total bulimic sample. Their mean age was 25.3 (6.1) years, 51% were of high social class, 34% of middle class origin, and 15% of low social class background. Alexithymia, depression, and eating pathology before and after treatment. Table 3 shows pa-
tients’ change in eating pathology, depression, and TAS scores from baseline to week 10. While there were no significant changes in mean TAS scores and HAM-D scores after 10 weeks of Table 3. Pretreatment
and Posttreatment
Comparisons for
treatment, there was a significant improvement (Wilcoxon’s matched-pairs signed-ranks test) in eating pathology as measured by the interviewerrated BINGE and VOMIT scales and the BITE. To check whether there were subsets of patients with increased and decreased TAS scores at week 10, we looked at what proportion of patients stayed above or below the cut-off point for alexithymia. At week 10, 73% of patients who had been alexithymic at baseline were still alexithymic (TAS score 2 74) and 87.5% of patients who at baseline were nonalexithymic (TAS score < 74) remained in this category. Correlation matrices (Kendall’s 7-b) were drawn up to establish (1) whether the TAS correlated with depression or eating pathology at baseline, and (2) whether baseline TAS predicted outcome at week 10 (Table 4). There was a highly significant positive correlation between baseline TAS (TAS 1) and week 10 TAS (TAS 2); however, the baseline TAS did not correlate with any of the other variables either at baseline or at week 10. Eating pathology at 10 weeks, as assessed with the observerrated measures (BINGE 2, VOMIT 2) was positively correlated with depression. TAS 2 had a significant positive correlation with BINGE 2. DISCUSSION
The results of study 1 suggest that eating disorder patients are more alexithymic than student controls of similar age and social class. The mean TAS scores of our eating disorder Table 4. Correlations Between TAS 1 and Observer-Rated Measures of Eating Pathology and Depression at Baseline (BINGE 1, VOMIT 1, HAM-D 1) and After 10 Weeks of Treatment Baseline TAS 1
Bulimic Patients in Study 2
(TAS 2, BINGE 2, VOMIT 2, HAM-D 2)
BINGE 1 -.04530
BINGE 1 Baseline
Week 10
P*
Mean (SD)
Binge score
3.8 (1 .OJ
2.8 (1.8)
.0016
0.4-1.5
TAS 1
Vomit score
3.5 (1.8)
2.9 (2.2)
.0076
0.2-1.1
TAS 2
26.7 (2.4)
23.1 (6.5)
.0012
1.4-5.8
BINGE 2
.0008
1.4-4.3
VOMIT 2
95% Cl
Bite severity
13.4 (3.3)
10.6 (4.1)
Ham-D
11 .O (4.8)
9.2 (7.0)
NS
TAS
70.7 (12.6)
69.8 (12.8)
NS
*Wilcoxon’s matched-pairs signed-ranks test.
.41995*
VOMIT 1
Mean (SD)
Bite symptom
VOMIT 1 -.01759
Week 10
*P < .05. tP <.Ol. SP <.OOl.
-HAM-D 1 .12295 .lOOll -.01641
-TAS 2 .58401$
-BINGE 2 .09965
-VOMIT 2 .00786
.29144x
.07230
.19170
.68212*
.33949t
HAM-D 2 .04977
.24233*
ALEXITHYMIA
57
IN EATING DISORDERS
patients were comparable, if not higher, than those found in other psychiatric patient populations (substance abusers,24 alcoholics4 mixed psychiatric outpatients,25x26 and psychosomatic patients”). Anorexic patients had significantly higher TAS scores than the bulimics. It can be argued that this might simply be a byproduct of starvation-induced cognitive impairment. However, it is unlikely that this fully explains the anorexic patients’ high scores, as there was no correlation between TAS scores and BMI within the anorexic groups. This is in keeping with the findings of the only other study” that used the TAS in an anorexic sample, and which noted that TAS scores were unrelated to degree of weight loss. A cross-sectional study like study 1 cannot shed any light on whether alexithymia precedes the development of an eating disorder or whether it occurs secondary to the eating disorder. However, in study 2, we attempted to address the state/trait issue for a group of bulimic patients, While patients’ eating pathology improved significantly over the 10 weeks of drug treatment with only minimal psychological support, their TAS scores remained stable. This suggests that the TAS does not simply vary with
clinical improvement. However, as the majority of patients had not fully recovered at the end of the 10 weeks, it can also be argued that their continuing high TAS scores were linked with persistent symptoms. The effects of psychological treatments on alexithymia are still far from clear. Two studies assessed alexithymia prospectively in anorexic* and newly recovered alcoholic4 inpatients and found that in a proportion of cases alexithymia worsened in the course of treatment, at least in the short term. In anorexia nervosa, it has been suggested that this may be the result of increasing demands and life problems facing the patient after weight restorations Thus, an alexithymic style of dealing with conflict, even if it develops secondary to a psychological disorder, may become a deeply ingrained pattern. which is hard to challenge. To elucidate the role of alexithymia in eating disorder patients further, longitudinal studies on anorexics and bulimics in treatment are needed. ACKNOWLEDGMENT We would like to thank Professor Russell for permitting us to involve the patients under his care in this research.
REFERENCES 1. Sifneos PE. Short-Term Psychotherapy Crisis. Cambridge, MA: Harvard University
and Emotional Press, 1972.
2. Taylor GJ. Alexithymia: concept, measurement, and implications for treatment. Am J Psychiatry 1984;141:725732. 3. Lesser IM. Alexithymia. N Engl J Med 1985;312:690692.
10. Engel K, Meier I. Clinical process studies on anxiety and aggressiveness affects in the inpatient therapy of anorexia nervosa. Psychother Psychosom 1988;50:125-133. 11. Bourke MP, Taylor GJ. Parker JD. Bagby RM. Alexithymia and neuroticism in anorexia nervosa. Paper presented at the International Symposium for Eating Disorders, Paris, April 17-19, 1991.
4. Haviland MG, Shaw DG. Cummings MA, MacMurray JP. Alexithymia: subscales and relationship to depression. Psychother Psychosom 1988;50:164-170. 5. Wise TN, Mann LS, Mitchell JD, Hryvniak M. Hill B. Secondary alexithymia: An empirical validation. Compr Psychiatry 1990;31:284-288.
12. Taylor GJ, Ryan D, Bagby MR. Toward the development of a new self-report alexithymia scale. Psychother Psychosom 1985;44:191-199,
6. Minuchin S, Rosman BL, Baker L. Psychosomatic Families. Anorexia Nervosa in Context. Cambridge, MA: Harvard University Press, 1978.
14. Taylor GJ, Bagby RM, Ryan DP, Parker JDA. Validation of the alexithymia construct: a measurementbased approach. Can J Psychiatry 1990;35:390-297.
7. Garner DM. The Eating Disorder Inventory-2. Professional Manual. Odessa. FL: Psychological Assessment Resources, Inc., 1991.
15. Bagby RM. Taylor GJ, Atkinson L. Alexithymia: a comparative study of three self-report measures. J Psychosom Res 1988;32:107-116.
8. Bourke MP, Taylor GJ, Crisp A. Symbolic functioning in anorexia nervosa. J Psychiatr Res 198.5;19:273-278.
16. Parker JDA. The Alexithymia Construct: relationship with sociodemographic variables and intelligence. Compr Psychiatry 1989;30:434:440.
9. Pierloot RA. Houben nervosa patients alexithymic? 222-232.
ME, Acke G. Are anorexia Acta Psychiatr Belg 1988:88:
13. Davis MS, Marsh L. Self-love, self-control and alexithymia: narcissistic features of two bulimic adolescents. Am J Psychother 1986;15:224-232.
17. Henderson M, Freeman CPL. A self-rating bulimia: the ‘Bite’. Br J Psychiatry 1987;150:18-24.
scale for
58
18. Cooper PJ, Taylor MJ, Cooper Z, Fairburn CG. The development and validation of the Body Shape Questionnaire. Int J Eat Disord 1987;6:485-494. 19. Walsh T. Classification of eating disorders in DSMIV. Paper presented at the International Symposium on Eating Disorders, Paris, April 17-19, 1991. 20. Guy W. ECDEU Assessment Manual for Psychopharmacology. Rockville, MD: US Department of Health, Education and Welfare, 1976:516-520. 21. Hamilton M. Development of a rating scale for primary depressive illness. Br J Sot Clin Psycho1 1967;6:278296. 22. Norusis MJ. SPSS/PC+ V2.0 Base Manual. SPSS Inc., Chicago, IL 60611,1988.
SCHMIDT, JIWANY, AND TREASURE
23. Altman DG. Practical Statistics for Medical Research. London, England: Chapman & Hall, 1991. 24. Taylor GJ, Parker JD, Bagby RM. A preliminary investigation of alexithymia in men with psychoactive substance dependence. Am J Psychiatry 1990;147:1228-1230. 25. Bagby RM, Taylor GJ, Parker JAD, Loiselle C. Cross-validation of the factor structure of the Toronto Alexithymia Scale. J Psychosom Res 1990;34:47-50. 26. Parker JDA, Bagby RM, Taylor GJ. Alexithymia and depression: distinct or overlapping constructs. Compr Psychiatry 1991;32:387-394. 27. Rubino IA, Grass0 S, Sonnino A, Pezzarossa B. Is alexithymia a non-neurotic personality dimension. Br J Med Psycho1 1991;64:385-391.
Study of Alexithymia Ulrike Schmidt,
Arif Jiwany,
The aims of the study were (1) to establish whether alexithymia is present in patients with bulimia nervosa (BN), (2) to compare bulimic patients with restricting anorexics (AN/R), bulimic anorexics (AN/BN), and normal controls with regard to alexithymia, (3) to determine whether in BN patients alexithymia is a state or a trait, and (4) to see whether alexithymia predicts short-term treatment outcome in BN. Study 1 included 173 eating disorder patients (BN: n = 93, AN/R: n = 55, AN/BN: n = 25) who were compared with 95 controls on the Toronto Alexithymia Scale (TAS). Study 2 included 41 BN patients who were assessed prospectively with the TAS before and after a
A
LEXITHYMIA was first used to describe a personality trait characteristic of psychosomatic patients,’ but has since been applied to patients across a wide range of psychological disorders.* Alexithymia denotes an inability to experience and express emotions and to discriminate between emotional states and bodily sensations. Alexithymic individuals are said to be concrete in speech and thought and to have an impoverished fantasy life.3 Alexithymia has also been conceptualized as a defense mechanism against emotional distress and pain in substance abusers4 and patients with severe physical illness.5 It has been argued that anorexia nervosa is a paradigm of psychosomatic illness.6 The Interoceptive Awareness Subscale of the Eating Disorder Inventory’ has some overlap with the alexithymia construct, and anorexic and bulimic patients score abnormally on it compared with non-eating-disordered control subjects. Several studies have measured alexithymia in anorexic patients, albeit with different methods and conflicting results. 8-11On the Toronto Alexithymia Scale (TAS),12 anorexic patients were more alexithymic than normal controls,” whereas when alexithymia was assessed on speech samples, anorexic patients were less alexithymic than surgical inpatients.‘O In a study using some
From the Institute of Psychiatry and Maudsley Hospital, London; and the University College Hospital and Middlesex Hospital Medical School, London, England. Address reprint requests to Ulrike Schmidt, M.D., Institute of Psychiatry, De Crespigny Park, London SE5 8AZ, England. Copyright 0 1993 by W.B. Saunders Company 0010-440x/93/3304-0018$03.00/0
54
in Eating
Disorders
and Janet Treasure lo-week drug treatment. AN/R patients in study 1 had significantly higher alexithymia scores than BN patients. All three eating disorder groups had significantly higher alexithymia scores than controls. For BN patients in study 2, TAS scores before and after drug treatment were stable, despite significant symptomatic improvement. We conclude the following: (1) eating disorder patients are considerably more alexithymic than normal controls; and (2) in BN, alexithymia may be a trait, unaffected by clinical improvement unless psychological treatment, encouraging the expression of emotions is offered. Copyright 0 1993 by W.B. Saunders Company
Rorschach indices and the Minnesota Multiphasic Personality Inventory (MMPI), anorexia nervosa patients did not differ from neurotic controls.9 One study8 found alexithymia to increase with weight restoration, whereas two other studies found no such link.9J1 Patients with bulimia nervosa often respond to stress by bingeing and vomiting, but find it difficult to make a link between their behavior and emotional triggers.13 This suggests that alexithymia might play a role in the psychopathology of these patients; however, this hypothesis has not yet been tested. The aims of the study presented here were (1) to establish whether alexithymia is present in patients with bulimia nervosa, (2) to compare bulimic patients with restricting anorexics, bulimic anorexics, and normal controls with regard to alexithymia, (3) to determine whether in bulimia nervosa patients alexithyrnia is a state or a trait, and (4) to see whether alexithymia predicts short-term treatment outcome in bulimia nervosa. METHOD To answer the above questions, two studies were conducted, one cross-sectional (study 1) and the other prospective (study 2).
Study 1 A consecutive series of patients referred to the Maudsley Hospital Eating Disorder Clinic were sent the following questionnaires before their first appointment: (1) The TAS, is a 26-item self-rating questionnaire, following a likert format. The TAS is a reliable and valid measure of the alexithymia construct,14 and is superior to other measures of alexithymia.15 In nonpatient populations, scores are not associated with age, education, or socioeconomic status.16
Comprehensive
Psychiatry, Vol. 34, No. 1 (January/February),
1993: pp 54-59
ALEXITHYMIA
55
IN EATING DISORDERS
The maximum score is 130. In accordance with previous studies, a score of 74 or greater on the TAS was chosen as the cut-off point for alexithymia.‘4J5 (2) The Bulimic Investigatory Test, Edinburgh (BITE),” is a 33-item self-rating instrument that measures bulimic symptomatology. It consists of a symptom scale (maximum score. 30; a score of 20 or more indicates highly disordered eating and the presence of binge eating) and a severity scale (maximum score, 33; a score of 5 or above is considered clinically significant). (3) The Body Shape Questionnaire (BSQ)‘s is a 34-item questionnaire designed to measure body shape concerns in eating disorder patients. The maximum score is 204. Only those patients of the series who at their first clinical assessment fulfilled DSM-III-R criteria for bulimia nervosa (BN) or anorexia nervosa were included in this study. Patients with anorexia nervosa were subdivided into those with restricting anorexia nervosa (AN/R) and those with a bulimic subtype (ANIBN), as there is growing evidence that these two groups differ from each other in a number of ways, including their psychopathological concomitants.” Patients with obesity, eating disorder not otherwise specified, or other main diagnoses were excluded from the sample. The TAS was also given to a control group of university students. Socioeconomic status was determined by the Hollingshead two-factor method and was based on father’s occupation.Z0
Study 2 Forty-one BN patients who took part in a IO-week drug treatment study (2 weeks single-blind placebo wash-out followed by 8 weeks double-blind placebo-controlled fluvoxamine) were studied prospectively. These patients were a subgroup of the total sample, which simply comprised those bulimic patients who had been referred since October 1989, when the drug study was started. They were given the TAS, the BITE, the BSQ, the Hamilton Depression (HAM-D) scale?’ and an interviewer-rated assessment of binge and vomit frequency before and after treatment.
Stu t&tics Data were analyzed using SPSS-PC+.2” The groups were compared using analysis of variance (ANOVA). Duncan’s multiple-range tests were performed, to reduce the type I
Table 1. Sociodemographic
Sex (n) Mean age 2 SD (yr)
error rate, which is inflated when many comparisons are performed.‘3 Ninety-five percent confidence intervals (CI) for the means of samples or differences between means are presented where appropriate.Z3 Kendall’s 7-b was calculated for within-group correlations. Wilcoxon’s matched-pairs signed-ranks test was used to compare changes within groups over time and treatment.
RESULTS
Study 1 Sample characteristics. One hundred seventy three female eating disorder patients were included in the study: 93 had BN, 55 had AN/R, and 25 had AN/BN. The control group comprised 48 female and 47 male students. Table 1 shows the age and class distribution of eating disorder patients and controls and gives information on body mass index (BMI = weight/ height2) and eating symptomatology of eating disorder patients. Eating disorder patients and controls were comparable in social class; however, the control group was younger than the clinical groups (ANOVA: F ratio = 4.56, F probability = .OOl). As expected, patients with BN were of normal weight, whereas AN/R and AN/BN subjects were both underweight. Patients with bulimic disorders had BITE symptom and severity scores and BSQ scores comparable to other bulimic samples,17~18whereas AN/R subjects-as expected-had lower scores. Alexithymia. Table 2 shows the means, standard deviations, and ranges of TAS scores. ANOVA showed a significant group effect (F ratio = 10.9, F probability = .OOl). Patients with AN/R had significantly higher scores than patients with BN, and all three eating disorder
Characteristics of Patients and Controls and Patients’ Eating Pathology
BN
AN/R
F (93) 23.8 + 5.1
F (55) 23.6 + 5.7
ANiBN
Controls
F (25) 22.4 k 5.9
F (48) 21.0 + 3.0
M 147) 21.2 k 2.5 71%
Social class High
58%
56%
54%
72%
Middle
28%
33%
27%
19%
1 1%
Low
14%
1 1%
18%
9%
18%
BMl* t SD
21.3 + 2.6
15.8 + 2.3
17.6 k 2.0
BITE symptomt k SD
25.8 + 3.0
13.5 k 7.3
21.4 + 6.3
BITE severity t SD BSQ* 2 SD
13.3 + 4.7 148.1 f 27.5
4.2 k 5.3 105.3 k 36.5
10.4 k 6.8 137.5 2 43.7
*Body mass index: This was not calculated for three patients with a bulimic disorder and three patients with restricting anorexia nervosa, as patients’ heights had been omitted from the case notes. tBlTE and SBSQ: Not all eating disorder patients were given these two questionnaires in addition to the TAS (BITE: BN, n = 87; AN-R, n = 30; AN/BN, n = 14. BSQ: BN, n = 83; AN/R, n = 28; AN/BN, n = 13).
56
SCHMIDT, JIWANV, AND TREASURE
Table 2. TAS: Means, Standard Deviations, 95% Confidence Intervals of Means, and Ranges
Mean(SD)
Cl (95%)
BN
93
72.4 (10.9)
70.2-74.6
41-98
AN/R
55
76.5 (12.8)
73.1-79.9
46-124
AN/EN
25
74.2 (13.1)
68.8-79.6
52-102
Female students
48
66.8 (9.3)
64.1-69.5
46-84
Male students
47
63.6 (11.2)
60.3-66.9
42-90
”
Range
NOTE. Significant group effect by ANOVA (F ratio = 10.9, F probability = ,001). Duncan’s range test: AN/R Y BN and AN/R, AN/BN, BN v male and female control patients are all significant at the .05 level.
groups differed from female and male controls (Duncan’s range test). In the bulimic group, 46 (50%) scored above the cut-off point for alexithymia; in the restricter group, 31 (56%); and in the mixed AN/BN group, 12 (48%). This contrasted with 13 (27%) and 9 (19%) in female and male controls. This difference was significant (x2 test: df = 4, P = .0002). Correlation matrices for TAS, BMI, BITE, and BSQ were calculated for each of the eating disorder groups using Kendall’s 7-b. The TAS did not correlate with any of these variables in any of the three groups. Study 2 Sample characteristics. The 41 patients who took part in the drug-treatment study were very similar to the total bulimic sample. Their mean age was 25.3 (6.1) years, 51% were of high social class, 34% of middle class origin, and 15% of low social class background. Alexithymia, depression, and eating pathology before and after treatment. Table 3 shows pa-
tients’ change in eating pathology, depression, and TAS scores from baseline to week 10. While there were no significant changes in mean TAS scores and HAM-D scores after 10 weeks of Table 3. Pretreatment
and Posttreatment
Comparisons for
treatment, there was a significant improvement (Wilcoxon’s matched-pairs signed-ranks test) in eating pathology as measured by the interviewerrated BINGE and VOMIT scales and the BITE. To check whether there were subsets of patients with increased and decreased TAS scores at week 10, we looked at what proportion of patients stayed above or below the cut-off point for alexithymia. At week 10, 73% of patients who had been alexithymic at baseline were still alexithymic (TAS score 2 74) and 87.5% of patients who at baseline were nonalexithymic (TAS score < 74) remained in this category. Correlation matrices (Kendall’s 7-b) were drawn up to establish (1) whether the TAS correlated with depression or eating pathology at baseline, and (2) whether baseline TAS predicted outcome at week 10 (Table 4). There was a highly significant positive correlation between baseline TAS (TAS 1) and week 10 TAS (TAS 2); however, the baseline TAS did not correlate with any of the other variables either at baseline or at week 10. Eating pathology at 10 weeks, as assessed with the observerrated measures (BINGE 2, VOMIT 2) was positively correlated with depression. TAS 2 had a significant positive correlation with BINGE 2. DISCUSSION
The results of study 1 suggest that eating disorder patients are more alexithymic than student controls of similar age and social class. The mean TAS scores of our eating disorder Table 4. Correlations Between TAS 1 and Observer-Rated Measures of Eating Pathology and Depression at Baseline (BINGE 1, VOMIT 1, HAM-D 1) and After 10 Weeks of Treatment Baseline TAS 1
Bulimic Patients in Study 2
(TAS 2, BINGE 2, VOMIT 2, HAM-D 2)
BINGE 1 -.04530
BINGE 1 Baseline
Week 10
P*
Mean (SD)
Binge score
3.8 (1 .OJ
2.8 (1.8)
.0016
0.4-1.5
TAS 1
Vomit score
3.5 (1.8)
2.9 (2.2)
.0076
0.2-1.1
TAS 2
26.7 (2.4)
23.1 (6.5)
.0012
1.4-5.8
BINGE 2
.0008
1.4-4.3
VOMIT 2
95% Cl
Bite severity
13.4 (3.3)
10.6 (4.1)
Ham-D
11 .O (4.8)
9.2 (7.0)
NS
TAS
70.7 (12.6)
69.8 (12.8)
NS
*Wilcoxon’s matched-pairs signed-ranks test.
.41995*
VOMIT 1
Mean (SD)
Bite symptom
VOMIT 1 -.01759
Week 10
*P < .05. tP <.Ol. SP <.OOl.
-HAM-D 1 .12295 .lOOll -.01641
-TAS 2 .58401$
-BINGE 2 .09965
-VOMIT 2 .00786
.29144x
.07230
.19170
.68212*
.33949t
HAM-D 2 .04977
.24233*
ALEXITHYMIA
57
IN EATING DISORDERS
patients were comparable, if not higher, than those found in other psychiatric patient populations (substance abusers,24 alcoholics4 mixed psychiatric outpatients,25x26 and psychosomatic patients”). Anorexic patients had significantly higher TAS scores than the bulimics. It can be argued that this might simply be a byproduct of starvation-induced cognitive impairment. However, it is unlikely that this fully explains the anorexic patients’ high scores, as there was no correlation between TAS scores and BMI within the anorexic groups. This is in keeping with the findings of the only other study” that used the TAS in an anorexic sample, and which noted that TAS scores were unrelated to degree of weight loss. A cross-sectional study like study 1 cannot shed any light on whether alexithymia precedes the development of an eating disorder or whether it occurs secondary to the eating disorder. However, in study 2, we attempted to address the state/trait issue for a group of bulimic patients, While patients’ eating pathology improved significantly over the 10 weeks of drug treatment with only minimal psychological support, their TAS scores remained stable. This suggests that the TAS does not simply vary with
clinical improvement. However, as the majority of patients had not fully recovered at the end of the 10 weeks, it can also be argued that their continuing high TAS scores were linked with persistent symptoms. The effects of psychological treatments on alexithymia are still far from clear. Two studies assessed alexithymia prospectively in anorexic* and newly recovered alcoholic4 inpatients and found that in a proportion of cases alexithymia worsened in the course of treatment, at least in the short term. In anorexia nervosa, it has been suggested that this may be the result of increasing demands and life problems facing the patient after weight restorations Thus, an alexithymic style of dealing with conflict, even if it develops secondary to a psychological disorder, may become a deeply ingrained pattern. which is hard to challenge. To elucidate the role of alexithymia in eating disorder patients further, longitudinal studies on anorexics and bulimics in treatment are needed. ACKNOWLEDGMENT We would like to thank Professor Russell for permitting us to involve the patients under his care in this research.
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