Psychosomatics 43:55-60, February 2002
© 2002 The Academy of Psychosomatic Medicine
Relationship Between Somatosensory Amplification and Alexithymia in a Japanese Psychosomatic Clinic
Mutsuhiro Nakao, M.D.,
Arthur J. Barsky, M.D.,
Hiroaki Kumano, M.D., and
Tomifusa Kuboki, M.D.
Received March 15, 2001; revised May 31, 2001; accepted June 22, 2001. From the Teikyo University Center for Evidence-Based Medicine and Department of Hygiene and Public Health, School of Medicine, Teikyo University, Tokyo, Japan; the Department of Psychosomatic Medicine, School of Medicine, University of Tokyo, Tokyo, Japan; and the Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA. Address reprint requests to Dr. Nakao, Department of Hygiene and Public Health, School of Medicine, Teikyo University, 2–11–1 Kaga, Itabashi, Tokyo 173–8605, Japan. E-mail: aaaa-tky{at}umin.ac.jp
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ABSTRACT
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To examine the relationship between somatosensory amplification and three factors of alexithymia (difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking), 48 outpatients attending a Japanese psychosomatic clinic and 33 comparative outpatients completed the Somatosensory Amplification Scale (SSAS), 20-item Toronto Alexithymia Scale (TAS-20), Profile of Mood States (POMS), and other self-rating questionnaires. The scores on the SSAS and the first and second TAS-20 factors were higher (all P<0.001) in the psychosomatic group than in the comparison group. The SSAS was positively associated (both P<0.01) with these two TAS-20 factors, controlling for the effects of age, sex, group, and POMS tension-anxiety and depression. Somatosensory amplification appears to be associated with difficulties identifying and describing feelings, not externally oriented thinking, in Japanese patients.
Key Words: Alexithymia • Mood States • Psychosocial Stress
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INTRODUCTION
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Somatosensory amplification refers to the tendency to experience somatic sensation as intense, noxious, and disturbing.1 The construct of somatosensory amplification is helpful in the assessment of the perceptual style of somatization and in the conceptualization of psychosomatic illness.1 The Somatosensory Amplification Scale (SSAS) was designed and validated to measure this phenomenon.2
Alexithymia is a personality construct derived from clinical observations of patients with psychosomatic diseases, characterized by difficulty distinguishing between emotions and bodily sensations.3 The Toronto Alexithymia Scale (TAS) and its modified versions, the TAS-R and TAS-20, are among the most common questionnaires to measure this construct.4,5
Evidence has suggested that the tendency to develop functional somatic symptoms is associated with alexithymia.6–10 A recent study reported that the SSAS was significantly correlated with the total TAS in the psychiatric sample.11 Some studies, however, have failed to find an association.12–14
One possible reason for the discrepancy of the results might be multiple aspects of alexithymia. One of the major domains of alexithymia, excessive preoccupation with external events, seems to reflect different aspects as compared with the cognitive inability to accurately perceive and report a full range of affects. A Japanese study15 indicated that the TAS-20 factor of "externally oriented thinking" was not statistically correlated with the other two TAS-20 factors of "difficulty identifying feelings" and "difficulty describing feelings." Thus it might be crucial to separate a construct of alexithymia into its composing factors in analysis when the relationship between somatosensory amplification and alexithymia is argued.
We hypothesized that somatosensory amplification is primarily associated with difficulties in identifying and describing feelings because inappropriate coping of negative feelings like anxiety and depression is closely linked to the increases in stress responses and bodily sensations.16,17 To examine this hypothesis, both the SSAS and TAS-20 were applied to a cohort of patients attending psychosomatic and general medicine clinics in the university setting. Both scale scores were compared between the two groups, and the SSAS was predicted from the TAS-20 subscales, controlling for the effects of age, sex, and mood states.
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METHODS
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Subjects
The study population included 48 consecutive outpatients (32 women and 16 men) attending the Psychosomatic Clinic at the Branch Hospital of the University of Tokyo. The average age was 36 (SD±14). All patients were referred from departments within the hospital or from clinics outside the hospital. Selection criteria were as follows: those who were 1) referred for "psychosomatic illnesses," 2) were age 15–65 years, 3) were able to visit the clinic during the study period, 4) whose medical conditions were stable without changes of medication for more than 1 month, and 5) did not have major depression or schizophrenia. Concerning criterion 1, the Japanese Society of Psychosomatic Medicine defines "psychosomatic illness" as any physical condition with organic or functional damages affected by psychosocial factors in the process of onset or development of the conditions.18 Concerning criterion 5, exclusion of psychiatric conditions was based on DSM-IV and done during the first intake interview.19 The study was approved by a committee of the hospital and conducted with patients' informed written consent in September 2000.
A total of 52 patients met the criteria, but 4 (8%) did not visit the clinic on the appointed day. The ICD-10 (International Statistical Classification of Diseases and Related Health Problems, Tenth Edition) diagnoses in the psychosomatic group were eating disorders (n=12), autogenic nervous dysfunction (n=9), irritable bowel syndrome (n=2), neurotic gastritis (n=2), spasmodic torticollis (n=2), writer's cramp (n=2), migraine (n=1), neurocirculatory asthenia (n=1), hyperventilation (n=1), gastric ulcer (n=1), hyperhidrosis (n=1), psychogenic polyuria (n=1), and premenstrual syndrome (n=1). The remaining 12 patients were classified into the ICD-10 symptom codes (category R), including headache (n=3) and chest discomfort (n=2) without definite disease diagnoses. Although different from Western medicine, eating disorders are often referred to psychosomatic clinics in Japan.20
A comparison sample (n=33) was randomly selected from outpatients attending the General Internal Medicine Clinic within the hospital during the study period. The total number of outpatients visiting this clinic was estimated to be approximately 1,200 during this period. Major ICD-10 diagnoses in the comparison group were essential hypertension (n=13), diabetes mellitus (n=7), hyperlipidemia (n=3), chronic hepatitis (n=3), iron deficiency anemia (n=2), chronic nephritis (n=2), and others (n=3). The ratio of women to men was 17:16, and the average age was 48 (SD±14). Gender was comparable between the two groups (P>0.05,  2 test), but the average age was younger in the psychosomatic group than in the comparison group (P<0.001, Student t-test, two-tailed).
Measures
Somatosensory Amplification Scale
The SSAS asks the respondent the degree to which 10 statements are "characteristic of you in general," on an ordinal scale from 1 to 5. In our data the Japanese version of SSAS had good intrascale consistency (Cronbach's alpha=0.79) as well as construct and criterion validity in a Japanese psychosomatic medicine sample.21
Twenty-Item Toronto Alexithymia Scale
The TAS-20 is a self-report questionnaire assessing alexithymic characteristics on a five-point scale. The Cronbach's alpha of the TAS-20 was 0.74 in the Japanese psychiatric outpatient sample.15 Three TAS-20 factors reported in the previous studies5,15,22 were analyzed in this study. The first factor of "difficulty identifying feelings" included seven items (e.g., "I am often confused about what emotion I am feeling"). The second factor of "difficulty describing feelings" included five items (e.g., "It is difficult for me to find the right words for my feelings"). The third factor of "externally oriented thinking" included the remaining eight items (e.g., "I prefer talking to people about their daily activities rather than their feelings").
Medical Symptom Checklist and Self-Rated Stress Perception Scale
These two questionnaires are clinical tools for evaluation of somatic symptoms and stress perception at the Mind/Body Medicine Clinic, Beth Israel Deaconess Medical Center.23,24 The Medical Symptom Checklist was used to assess the following 16 common somatic symptoms: headache, visual symptoms, dizziness, ringing in the ears, nausea/vomiting, diarrhea, constipation, abdominal pain, muscle pain, joint pain, back pain, chest pain, palpitation, shortness of breath, insomnia, and fatigue. Symptoms scored as occurring once a week or more often were defined as "positive" symptoms. The total number of "positive" somatic symptoms was analyzed in the study.23,24
The Stress Perception Scale was used to assess the degree to which patients reported stress in seven areas of life. The seven areas are evaluated on an 11-point scale (0=no stress to 10=worst stress possible) and include work, family, and neighborhood relations, as well as living-, social-, financial-, and health-related situations. The average score of the seven areas was analyzed in the study.24
Profile of Mood States (POMS)
The POMS has 65 items and consists of the following six mood-state scales: tension-anxiety, depression, anger-hostility, vigor, fatigue, and confusion.25 The reliability and validity of the POMS have been examined in the Japanese population.26 The POMS tension-anxiety and depression scales are analyzed in the study. The two POMS scales are particularly relevant because high utilizers of medical care tend to show high levels of distress on these scales27 and because distress related to subsyndromal anxiety and depression have been shown to be prevalent and problematic to treat in medical care.28
Data Analysis
Scores of all the questionnaires were expressed as means and standard deviations. Because mean age was statistically different between the psychosomatic and comparison groups, analysis of covariances was used to compare the scores between the psychosomatic group and comparison group, controlling for the effects of age.
Correlational analysis was then used to assess the association between the SSAS and TAS-20 scores. Multiple regression analysis was performed to determine the independent effects of TAS-20 scores on the SSAS scores, controlling for the effects of age, gender, group (psychosomatic/comparison), and the POMS tension-anxiety and depression scales on the SSAS scores.
All analyses were performed using the SAS statistical package.29
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RESULTS
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Group Comparisons
The SSAS scores and the TAS-20 scores of "difficulty identifying feelings" and "difficulty describing feelings" were higher (both P<0.001) in the psychosomatic group than in the comparison group, but those of "externally oriented thinking" were comparable between the two groups. The total number of somatic symptoms, degree of self-rated stress perception, and scores on the POMS tension-anxiety and depression scales were also higher (all P<0.001) in the psychosomatic group than in the comparison group (Table 1).
Relationship Between the SSAS and TAS-20; Psychosomatic Variables
The SSAS scores were positively correlated (both P<0.001) with the TAS-20 scores of both "difficulty identifying feelings" and "difficulty describing feelings" in the total sample (Table 2). In the psychosomatic group the SSAS scores were positively correlated (P<0.05) only with scores of "difficulty identifying feelings." In the comparison group they were positively correlated (both P<0.005) with those of both "difficulty identifying feelings" and "difficulty describing feelings" in the comparison group; they were negatively correlated (P<0.001) with those of "externally oriented thinking" (Table 2).
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TABLE 2. Pearson correlation coefficients between Somatosensory Amplification Scale and Toronto Alexithymia Scale
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Concerning the other psychosomatic questionnaires, the SSAS scores were positively correlated (all P<0.05) with the total number of somatic symptoms, degree of self-rated stress perception, and scores on the POMS tension-anxiety and depression scales in the total sample. They were positively correlated (both P<0.005) with the total number of somatic symptoms and the POMS depression scale scores in the comparison group (Table 2).
Predictors of the SSAS
The results of multiple regression analysis indicated that the two TAS-20 factors "difficulty identifying feelings" and "difficulty describing feelings" were significantly and positively associated with the SSAS (both P<0.05) in the multiple regression analysis. The TAS-20 factor "externally oriented thinking" was not significantly associated with the SSAS (Table 3).
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DISCUSSION
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In the total sample, the SSAS was significantly associated with the two TAS-20 factors "difficulty identifying feelings" and "difficulty describing feelings" by the correlational analysis. The SSAS was still significantly associated with the TAS-20 factors "difficulty identifying feelings" and "difficulty describing feelings," controlling for the effects of age, gender, group, and mood states by multiple regression analysis.
It is interesting that the TAS-20 factor "externally oriented thinking" was not associated with the SSAS in this multiple regression analysis. One possible interpretation of the results is that alexithymia may be a culture-bound construct, and therefore the relationship between somatosensory amplification and the three domains of alexithymia might be specific to the Japanese psychosomatic population. For example, the magnitudes of intercorrelations between "externally oriented thinking" and the other two TAS-20 factors were somewhat higher in the Western studies5,22 than in the present study and a previous Japanese study.15 The previous Japanese study also reported that the "externally oriented thinking" factor was closely associated with social discomfort and hostility.15 Our preliminary data analysis support this phenomenon with high Pearson correlation coefficient (r=0.37, P=0.04) between the "externally oriented thinking" factor and the POMS anger-hostility scale in the comparison sample. Because aggressive or hostile behaviors are less preferable in Japanese society30 than in Western society, it is possible that the measurement of the "externally oriented thinking" factor might be affected by Japanese customs of suppression of aggressive or hostile behaviors and failed to find statistical positive correlations with the SSAS in the present study. A recent cross-cultural study indicated that major sources of differences in somatization among ethnocultural groups include styles of expressing mind/body distress.31 A future study is needed to investigate cross-cultural differences in the relations between somatosensory amplification and alexithymia.
The SSAS and TAS-20 scores were higher in patients attending the psychosomatic clinic than in the comparison sample. Those who attended the clinic were in general referred because of psychosomatic distress, troublesome somatic symptoms, and higher degrees of psychosocial distress. However, there were stronger associations in the comparison group between the SSAS and TAS-20 factors (and other psychosomatic variables). These findings were consistent with a U.S. study showing that the total number of psychosomatic symptoms were related less to the SSAS scores in hypochondriacal patients than in the comparison sample in a general medicine clinic.2 Although it is not conclusive, it might be possible that the SSAS shares common features with alexithymic domains within certain levels of psychological distress but also reflects other independent aspects unrelated to alexithymia among those who could definitely be diagnosed with psychosomatic disorders.
Age and female gender predicted the SSAS scores in the multiple regression analyses. The age effects were interesting because the SSAS scores in the psychosomatic group were significantly higher than those in the comparison group, despite the average younger age. Concerning gender, several studies carried out in different settings have demonstrated gender differences in the reporting of somatic symptoms.32 An integrated behavioral approach focusing on the effects specific ages and gender have on the SSAS might give researchers clues to further understanding the linkage between somatosensory awareness and alexithymia, taking into consideration biological sensitivity to bodily stimuli, sick-role behavior, reluctance of admitting somatic symptoms, and social support.
The main limitation of our study is the great diagnostic heterogeneity within both groups. The sample was identified on the basis of patients' illness behaviors (complaints of mind/body symptoms) rather than on the basis of pathophysiology because physical symptoms are generally the major reason for outpatient visits to physicians and are often difficult to diagnose.33 As a result, the psychosomatic group included a fair number (25%) of patients with eating disorders (often not considered psychosomatic in Western countries), and the comparison group included a number (40%) of nonsymptomatic hypertension (classically thought of as psychosomatic). The data might generalize only to persons visiting a Japanese psychosomatic clinic, not to patients diagnosed with well-defined diseases. Additionally, the sample was small and selected from a university hospital. A large cohort study should be conducted with patients with specific disease diagnoses. Finally, the cross-sectional nature of the study does not permit any conclusions about the direction of causality between somatosensory amplification and alexithymia.
It makes sense not only statistically but also clinically that somatosensory amplification is associated with alexithymic characteristics of difficulties identifying and describing feelings. The roles of somatosensory amplification in clinical conditions should be studied further to clarify the pathogenesis of psychosomatic illness.
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ACKNOWLEDGMENTS
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The authors thank the staff at the Departments of Psychosomatic Medicine and Internal Medicine, the Hospital of the University of Tokyo, for their help in data collection. This study was partly supported by the Okinaga Harvard Fellowship, organized by the Teikyo University in Japan.
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REFERENCES
|
-
Barsky AJ, Goodson JD, Lane RS, et al: The amplification of somatic symptoms. Psychosom Med 1988; 50:510-519[Abstract/Free Full Text]
-
Barsky AJ, Wyshak G, Klerman GL: The somatosensory amplification scale and its relationship to hypochondriasis. J Psychiatr Res 1990; 24:323-334[CrossRef][Medline]
-
Sifneos PE: The prevalence of alexithymia characteristics in psychosomatic patients. Psychother Psychosom 1973; 22:255-262[Medline]
-
Taylor GJ, Bagby RM, Parker JDA: The revised Toronto Alexithymia Scale: some reliability, validity and normative data. Psychother Psychosom 1992; 57:34-41[CrossRef][Medline]
-
Bagby RM, Parker JDA, Taylor GJ: The Twenty-Item Toronto Alexithymia Scale. I. Item selection and cross-validation of the factor structure. J Psychosom Res 1994; 38:33-40[CrossRef][Medline]
-
Lesser IM: Current concepts in psychiatry: alexithymia. N Engl J Med 1985; 312:690-692[Medline]
-
Taylor GJ, Bagby RM, Parker JDA: The alexithymia construct: a potential paradigm for psychosomatic medicine. Psychosomatics 1991; 32:153-164[Abstract/Free Full Text]
-
Bagby RM, Taylor GJ, Ryan DP: Toronto Alexithymia Scale: relationship with personality and psychopathology measures. Psychother Psychosom 1986; 45:207-215[Medline]
-
Bagby RM, Taylor GJ, Atkinson L: Alexithymia: a comparative study of three self-report measures. J Psychosom Res 1988; 32:107-116[CrossRef][Medline]
-
Taylor GJ, Parker JDA, Bagby RM, et al: Alexithymia and somatic complaints in psychiatric out-patients. J Psychosom Res 1992; 36:417-424[CrossRef][Medline]
-
Wise TN, Mann LS: The relationship between somatosensory amplification, alexithymia, and neuroticism. J Psychosom Res 1994; 38:515-521[CrossRef][Medline]
-
Lesser IM, Ford CV, Friedmann CTH: Alexithymia in somatizing patients. Gen Hosp Psychiatry 1979; 3:256-261
-
Kosturek A, Gregory RJ, Sousou AJ, et al: Alexithymia and somatic amplification in chronic pain. Psychosomatics 1998; 39:399-404[Abstract/Free Full Text]
-
Gregory RJ, Manring J, Berry SL: Pain location and psychological characteristics of patients with chronic pain. Psychosomatics 2000; 41:216-220[Abstract/Free Full Text]
-
Fukunishi I, Nakagawa T, Kikuchi M, et al: Is alexithymia a culture-bound construct? Validity and reliability of the Japanese versions of the 20-Item Toronto Alexithymia Scale and modified Beth Israel Hospital Psychosomatic Questionnaire. Psychol Rep 1997; 80:787-799[Medline]
-
Marcus SC, Olfson M, Pincus HA, et al: Self-reported anxiety, general medical conditions, and disability bed days. Am J Psychiatry 1997; 154:1766-1768
-
Simon GE, Von Korff M, Piccinelli M, et al: An international study of the relation between somatic symptoms and depression. N Engl J Med 1999; 341:1329-1335[Abstract/Free Full Text]
-
The Committee of Education and Training of the Japanese Society of Psychosomatic Medicine: An updated treatment guideline of psychosomatic medicine. Jpn J Psychosom Med 1991; 31:537-576 [in Japanese]
-
American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition. Washington, DC, American Psychiatric Press, 1994
-
Nakao M, Nomura S, Yamanaka G, et al: Assessment of patients by DSM-III-R and DSM-IV in a Japanese Psychosomatic Clinic. Psychother Psychosom 1998; 67:43-9[CrossRef][Medline]
-
Nakao M, Kumano H, Kuboki T, et al: Reliability and validity of the Japanese Version of Somatosensory Amplification Scale: clinical application to psychosomatic illness. Jpn J Psychosom Med 2001; 41:539-547 [in Japanese]
-
Parker JDA, Bagby RM, Taylor GJ: Factorial validity of the 20-Item Toronto Alexithymia Scale. Eur J Pers 1993; 7:221-232
-
Nakao M, Fricchione G, Myers P, et al: Anxiety is a good indicator for somatic symptom reduction through a behavioral medicine intervention in a Mind/Body Medicine Clinic. Psychother Psychosom 2001; 70:50-57[CrossRef][Medline]
-
Nakao M, Myers P, Fricchione G, et al: Somatization and symptom reduction through a behavioral medicine intervention in a mind/body medicine clinic. Behav Med 2001; 26:159-168[Medline]
-
McNair DM, Lorr M, Droppleman LF: Profile of Mood States. San Diego, CA, Educational and Industrial Testing Service, 1971
-
Yokoyama K, Araki S, Kawakami N, et al: Production of the Japanese edition of Profile of Mood State (POMS): assessment of reliability and validity. Jpn J Public Health 1990; 37:913-918 [in Japanese]
-
Kuboki T, Nomura S, Wada M, et al: Multidimensional assessment of mental state in occupational health care - combined application of three questionnaires: Tokyo University Egogram (TEG), Time Structuring Scale (TSS), and Profile of Mood States (POMS). Environ Res 1993; 61:285-298[Medline]
-
Gonzales JJ, Magruder KM, Keith SJ: Mental disorders in primary care services: an update. Public Health Reports 1994; 109:251-258[Medline]
-
SAS Institute Inc: SAS/IMS User's Guide, Release 6.03 Edition. Cary, NC, SAS Institute Inc, 1988
-
Fukunishi I, Hosaka T, Berger D: Sociocultural differences on hostility in alexithymic persons. Psychol Rep 1995; 77:253-254[Medline]
-
Kirmayer LJ, Young A: Culture and somatization: clinical, epidemiological, and ethnographic perspectives. Psychosom Med 1998; 60:420-430[Abstract/Free Full Text]
-
Nakao M, Fricchione G, Zuttermeister PC, et al: Effects of gender and marital status on somatic symptoms of patients attending a mind/body medicine clinic. Behav Med 2001; 26:169-176[Medline]
-
Kroenke K, Arrington ME, Mangelsdorff AD. The prevalence of symptoms in medical outpatients and the adequacy of therapy. Arch Intern Med 1990; 150:1685-1689[Abstract]
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ABSTRACT
INTRODUCTION
