Somatization Disorder in Patients With Chronic Fatigue

Somatization Disorder in Patients With Chronic Fatigue PETER MANU. M.D. THOMAS J. LANE. M.D. DALE A. MATIHEWS. M.D.

One hundred adults with a chiefcomplaint ofchronic fatigue were evaluated in an outpatient setting to determine a possible association with somatization disorder. Somatization disorder was diagnosed in 15 patients. Eight functional somatic symptoms were reported more frequently by these patients: pain in extremities, joint paint, chest pain, other pain, shortness ofbreath, blurred vision. muscle weakness. and sexual indifference (p
hronic fatigue is a condition in which patients feel tired before they begin activities, have an abnonnal degree ofexhaustion following habitual activities, or lack the energy required to accomplish tasks that need sustained attention and effort. Chronic fatigue is a common complaint in primary care practice. As a chief complaint, chronic fatigue has a prevalence ranging from 4% to 9% of all office visits to internists and family physicians in the United States and Canada. I- 3 In epidemiologic studies, chronic fatigue has been reported by 21 % to 41 % of adult individuals.4-S Its impact on health care expenditures is considerable--..
C

Received July 22. 1988; revised December 7. 1988; accepted January 4, 1989. From the Depanment of Medicine. University of Connecticut School of Medicine. Farmington. Connecticut; and the Veterans Administration Medical Cen· ter, Newington. Connecticut. Address reprint requests to Dr. Manu, Division of General Medicine (AM.Q28). University of Connecticut School of Medicine, Farmington, cr 06032. Copyright CO 1989 The Academy of Psychosomatic Medicine.

388

Although chronic fatigue is associated with many acute and chronic medical illnesses, psychiatric disorders have been identified as its cause in 29% to 80% of patientsp·6-1O The psychiatric diagnoses reported include depression, anxiety, stress adjustment reaction, alcoholism, chronic nervous exhaustion, tension, and hectic Iife_style.2.3.U-'O Conspicuously absent were diagnoses classified as somatofonn disorders in the Diagnostic andStatistical Manual ofMental Disorders. Third Edition (DSM-lJI)1I or the Diagnostic and Statistical Manual of Mental Disorders. Third Edition, Revised(DSM-lJI-R). 12 The major features of illness grouped under somatofonn disorders are complaints and physical symptoms for which no organic basis can be demonstrated and which are presumably linked to psychological conflicts. Somatization disorder is among the disorders in this category. Fonnerly called hysteria, it is a chronic, fluctuating disorder that begins before the age of 30 and presents as multiple and recurrent physical complaints. '2 Although it rarely occurs in the community. somatization disorder has been identified in a relatively large PSYCHOSOMATICS

Manu etal.

number ofpatients with chronic complaints. such as chronic pain, irritable bowel syndrome, and functional visual loss. 13-16 In this study. we prospectively investigated the prevalence and clinical characteristics of somatization disorder in patients complaining of chronic fatigue. We used a standardized approach for both initial and follow-up data collection, including a medical history. physical examination. laboratory evaluation. and psychiatric interview. METHODS Data Collection The study was conducted in the Fatigue Clinic of the General Medicine Outpatient Module at the University of Connecticut Health Center in Farmington. Connecticut. The patients were evaluated in the order in which they called, from November 1986 through August 1987. Ninety-five patients were self-referred and five patients were seen at the request of other physicians. All patients met the entry criteria: age 18 years or older; no hospitalizations in the past three months; and feeling tired at least half the time for at least the past month. The evaluation included a complete medical history and physical examination, a resting electrocardiogram. an exercise stress test. a spirometric evaluation of pulmonary function, laboratory testing (complete blood count, urinalysis, erythrocyte sedimentation rate, automated blood chemistry profile. iron level, total iron-binding capacity, thyroid-stimulating hormone, T3 resinuptake, T4 radioimmunoassay. and Epstein-Barr virus serologies). and intradermal skin tests with 5 tuberculin units of purified protein derivative and Candida extract to test for physical causes of chronic fatigue. Additional investigations were ordered for individual cases if deemed necessary. After completing the medical examination. the patients were administered the National Institute of Mental Health Diagnostic Interview Schedule-Version III,'7 a structured interview designed to elicit consistent and accurate psychiatric diagnoses. The Diagnostic Interview SchedVOLUME 30 • NUMBER 4 • FALL 1989

ule has been extensively validated for the following categories: major depression. dysthymia. manic-depressive disorder, simple phobia, social phobia. panic disorder, agoraphobia, obsessivecompulsive disorder, somatization disorder, schizophrenia and schizophreniform disorder, alcohol abuse or dependence. drug abuse or dependence, and antisocial personality disorder. '7 - '9 The interview elicits the symptoms required for each of the 15 diagnoses and their severity. frequency, and distribution over time. Both current and lifetime diagnoses can be made. The Diagnostic Interview Schedule was administered and interpreted by a board-certified internist (PM) who had received formal training in its use according to Washington University's protocol. 17 Diagnostic Criteria for Somatization Disorder Somatization disorder was diagnosed if a patient had a history of many medical complaints that began before the age of 30 and persisted for several years and if at least 13 of 35 symptoms were present. The 35 symptoms were vomiting (other than during pregnancy). abdominal pain (other than when menstruating). nausea (other than motion sickness). bloating. diarrhea, intolerance to three or more foods. pain in the extremities (other than joints). back pain, joint pain, pain during urination. other pain (excluding headaches), shortness of breath, palpitations, chest pain. dizziness. amnesia. difficulty swallowing. loss of voice. deafness. double vision, blurred vision. blindness. fainting or loss of consciousness. seizures, trouble walking, paralysis or muscle weakness. urinary retention. burning sensation in sexual organs or rectum, sexual indifference, pain during intercourse. impotence, painful menstruation. irregular menstrual periods. excessive menstrual bleeding. and vomiting throughout pregnancy. To qualify as significant a symptom had to cause the patient to take medicine (other than over-the-counter analgesics). see a physician or other health professional. or alter his life-style; to have no organic explanation; and to have occurred at times other than during panic attacks. 12 389

Somatization Disorder and Chronic Fatigue

TABLE I. Lifetime psychiatric: diagnoses of 100 patients with chronic fatigue Females

Males (n=35)

(n=65)

Diagnostic Group

n

%

n

%

Total

Mood disorder

13

S2

Anxiety disorder

14 2

S8 12

S2 10

Psychoactive substance use disorder

II

39 38 8 29 14

60

Somatization disorder

37 40 6 31 26

4S

40 23

9

No diagnosis

Diagnostic Procedure The diagnostic procedure employed in the fatigue clinic has been presented in detail elsewhere. 20 Briefly, psychiatric diagnoses were made for each category in which the number and type of symptoms met the inclusion and exclusion criteria specified in DSM-llI-R. This was accomplished by hand scoring the Diagnostic Interview Schedule. 12 Medical diagnoses were based on criteria contained in the 1985 edition of Cecil's Textbook of Medicine. 21 The diagnoses were evaluated to determine if they could have caused the patient's fatigue in the context of the history of present illness, the past medical history, the review of symptoms, the results of the physical examination and laboratory tests, and the consultation reports. Six months after the initial visit, the patients were invited to return for a follow-up evaluation that included readministration of the Diagnostic Interview Schedule, a physical exam, and a review of the functional impairment produced by fatigue. Statistical Procedures Statistical analyses were performed by chisquare testing with Bonferroni's correction. Confidence intervals for proportions were calculated according to the standard formula. 22 RESULTS The subjects were 65 women and 35 men. The mean age of the sample was 41.4 years (range, 22 to 77). The mean duration of chronic fatigue was 13 years (range, 2.5 months to 70 years). Eighty 390

22

patients had been evaluated previously for fatigue, by an average of 4.5 physicians. The initial assessment identified 77 patients who had one or more lifetime psychiatric diagnoses. The prevalence of the diagnostic groups was similar in both men and women (Table I). Fiftynine patients received current psychiatric diagnoses, which included major depression (n=36), somatization disorder (n=lO), dysthymia (n=6), panic disorder (n=6), social phobia (n=3), and bipolar disorder (n=2). Twenty-two patients had two or more current psychiatric disorders; 12 patients had coexisting depressive illness and anxiety disorder. Organic causes of chronic fatigue were identified in five patients and included seizure disorder (n=2), obstructive sleep apnea (n=l), bronchial asthma (n=I), and polymyalgia rheumatica (n=I). Fifteen patients met immunological and clinical criteria for chronic, active Epstein-Barr viral infection. Forty-six patients reported for the extensive follow-up evaluation, which occurred an average of eight months after the initial visit. Somatization disorder was identified in five additional patients at follow-up. These patients had had between lO and 12 symptoms of somatization disorder at the initial evaluation. Thus, following the initial and follow-up evaluations, somatization disorder was identified in 15 patients (13 women and two men) who had complained of chronic fatigue. None of the patients with somatization disorder had any findings to indicate the presence of an organic illness. Six patients with somatization disorder believed organic disease would explain their chronic fatigue symptoms: two believed they had systemic candidiasis; one attributed fatigue to PSYCHOSOMATICS

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TABLE 1. Clinical characteristics of patients with somatization disorder (SO) and chronic fatigue

Sex

Age (years)

Age at Onset of Fatigue (years)

Age at Onset of SO (years)

Number of Physicians Seen (lifetime)

M

25

20

20

15

M F F F F F F F

36 34 52 58 50 50 52 37

29 14

21 16

6

lifelong

10

NAb

57 5 25 26

12 15 14 13 20

2 3 3 3 5

F F F

45 43 52

15 18 41

15 28 18

2 7

F F

26 43

23 32

23 8

2 12

F

35

30

12

6

17

I

I

Psychiatric Diagnoses Other than SO (lifetime) obsessive-compulsivedisorder. social phobia." simple phobia" major depression." cannabis abuse none alcohol abuse panic disorder major depression: social phobia simple phobia none panic disorder: obsessivecompulsive disorder none simple phobia bipolar disorder: panic disorder. alcohol abuse none major depression." agoraphobia. simple phobia. alcohol dependence cannabis abuse none

"1bese diagnoses were current at the time of the initial Diagnostic Interview Schedule evaluation. ~A=not available

chronic mononucleosis; one attributed fatigue to food allergy; one to sleep disorder; and one to multiple infections. No clinical evidence was found to support those beliefs. Chronic fatigue and somatization disorder produced only mild occupational impairment in the majority of patients. Only two patients had missed work because of illness in the year preceding our evaluation. The mean age of patients with chronic fatigue and somatization disorder was 42.5 years (range, 25 to 58 years). The mean age at the onset of somatization disorder was 16.3 years (range, eight to 28 years). Fatigue had been present for an average of 19 years. The mean age at onset of chronic fatigue was 23.5 years. The mean number of physicians previously consulted to treat the fatigue was 4.9 (Table 2). Ten patients with somatization disorder had at least one other lifetime psychiatric diagnosis, and five had current psychiatric diagnoses. The VOLUME 30· NUMBER 4' FALL 1989

prevalence of lifetime psychiatric disorders among chronic fatigue patients with and without somatization disorder was the same. However, a significantly greater proportion of patients with somatization disorder had no other current psychiatric diagnosis (Table 3). Eight symptoms were reported more frequently (p<.OOl) by patients with somatization disorder: pain in extremities, joint pain, other pain, shortness of breath, chest pain, blurred vision, muscle weakness or paralysis, and sexual indifference (Table 4). Thirteen patients with somatization disorder had five or more of these symptoms, compared with three patients without somatization disorder (p<.OOI). DISCUSSION In 1980. the Task Force on Nomenclature and Statistics of the American Psychiatric Association separated hysteria from chronic hypochon391

Somatization Disorder and Chronic Fatigue

TABLE 3. Comparison or psychiatric diagnoses or 100 chronic ratigue patients with and without somatization disorder (SD) Liretime DIagnoses

Diagnostic Group Mood disorder Anxiety disorder Psychoactive substance use disorders No diagnosis

Current DIagnoses

Patients wlthSD

Patients withoutSD

Patients withSD

(,,=15)

(,,=85)

(,,=15)

"

%

"

%

4 12 5

27 80

48

39

46

33

34

40

5

33

18

21

56

"

4 4

10

%

27 27

67

Patients withoutSD (,,=85)

"

%

40

47

28

33

10

12

28

33"

"Patients with somatization disorder received significantly more psychiatric diagnoses than patients without somatization disorder (p<.OO 1).

driasis, conversion reaction, and psychogenic pain and renamed it somatization disorder. The salient features of somatization disorder were considered to be multiple and recurrent physical complaints, beginning before the age of 30, for which medical attention had been sought, but for which no organic basis had been found. Although the concept of hysteria as a syndrome of multiple inexplicable physical complaints had been first proposed in 1859, objective criteria for its diagnosis were not formulated until a century later. Criteria included at least 25 of 60 symptoms distributed among at least nine of 10 organ- (or system-) specific groups of symptoms. 23.24 Fatigue was one of the symptoms of hysteria, and was grouped together with lump in throat, fainting spells, visual blurring, weakness, and dysphonia. In 1980, the total number of possible symptoms was reduced from 60 to 37, the 10 symptom groups were reduced to seven, the requirement that the symptoms be distributed over groups was dropped, and the total number of symptoms required to make a definite diagnosis was reduced from 25 to 14 for women and 12 for men. 1I Fatigue was no longer included among the symptoms required for diagnosis. Further revisions of the diagnostic criteria were published in 1987, when the number of symptoms was reduced from 37 to 35 and the number of symptoms required for a definite diagnosis was changed to 13 for both men and women: 2 392

The reported prevalence of somatization disorder varies according to the demographic and clinical characteristics of the sample studied and depending on whether the interviewer is a physician. In the Epidemiologic Catchment Area research program,2S a large-scale, communitybased study of 18,600 individuals, interviewers used the Diagnostic Interview Schedule l1 to determine the prevalence of somatization disorder in various regions in the United States. They found the prevalence to be 0% at the Los Angeles site; 0.1 % at the New Haven, Baltimore, and St. Louis sites; and 0.4% at the Piedmont, North Carolina site. 2S Other studies revealed prevalences of somatization disorder of I % in postpartum hospitalized women who had no active illnesses,26.21 and 5.6% in female psychiatric outpatients. 28 Much higher prevalences of somatization disorder have been identified in samples with special clinical characteristics: 27% of women who have had a hysterectomy for reasons other than cancer; 17% to 28% ofpatients with irritable bowel syndrome; 24% of patients with functional visual loss; and 12% of patients with chronic pain. 13-16.29 The chronic fatigue patients evaluated in this study had a prevalence of somatization disorder of 15%, which is comparable to the special clinical groups described above. The female predominance, noted in all previous clinical descriptions of somatization disorder, was present also in our patient population: 20% of women and 5.7% of PSYCHOSOMATICS

Manu et al.

TABLE 4. Symptoms or somatization disorder

(SO) reported by patients with chronic fatigue

Symptom Vomiting Abdominal pain Nausea Bloating Diarrhea Food intolerance Pain in exttemities" Back pain Joint pain" Pain during urination Other pain" Shortness of breath" Palpitations Chest pain" Dizziness Amnesia Lump in throat Loss of voice Deafness Double vision Blurred vision" Blindness Fainting Seizures Trouble walking Muscle weakness" Urinary retention Burning in sexual organs Sexual indifference" Impotence Pain during intercourse Painful menstruation Irregular menstrual periodsb Excessive menstrual bleedingb Vomiting throughout pregnancl

Patients with SO

Patients without SO

(n=IS)

(n=8S)

n

%

n

%

2

13 73 53

3 26

60

16 15 13 16 19 18 2 6 16 19 18 22 2 18 4 4 13

4 31 20 19 17 15 19 22 21 2 7 19 22 21 26 2 21 5 5 15 15 6 12

11

8 9 5 4 12 10 10

0 7 9 6

33 27 80 67 67 0 47 60 40

11

73

6 2 6 2

40 13 40

17

6 8

13 7 20 67 20 33 0 33 73 0 13 53 13 7 46 62

6

46

7

14

3

23

5

10

I

3 10

3 5 0 5 11

0 2 8 2 I

13

5 10

I

I

12

15 13

14 15 0 6 18 6 1 29 25

13

0 5 15 5 I

"Symptom was reponed significantly more by patients with somatization disorder (p<.OO I). "Reported by 65 female patients. 13 of whom had SO. men met the diagnostic criteria. The two men with somatization disorder also had current anxiety or affective disorders; in contrast, only three of the 13 females had other current psychiatric diagnoses. Both men appeared to fit the so-called "diversiform somatizer" pattern30: they were imVOLUME 30· NUMBER 4' FALL 1989

pulsive, easily distracted, exhibited a great deal of somatic anxiety, and had frequent brief episodes of illness. On the other hand, our female patients with somatization disorder were a heterogeneous group: some presented their symptoms and medical history in a dramatic, colorful, or exaggerated way; others appeared to focus on fatigue, had decreased involvement in social activities, and described other symptoms in a vague and sometimes contradictory fashion. Community studies have found that pain in the chest, abdomen, and back and reproductivesystem symptoms in females were the somatization symptoms most commonly reported by randomly selected adults. 31 In contrast, the chronic fatigue patients who had somatization disorder more frequently reported pain in the extremities, joint pain, muscle weakness, shortness of breath when not exerting themselves, blurred vision, and sexual indifference. These symptoms appeared to correlate with a perception by these patients of their inability to engage in habitual activities. Thus, this group of symptoms could be useful when screening patients with chronic fatigue for somatization disorder. Our study has limitations and the results should be interpreted with caution for several reasons: Patients for whom chronic fatigue had been diagnosed and treated satisfactorily by other physicians are not represented in our study. Our patients were not randomly selected and were largely self-referred, creating a "sample of convenience" of questionable representativeness. The assessment tool that we used-Diagnostic Interview Schedule-Version III-did not include disorders, such as generalized anxiety disorder or posttraumatic stress disorder, in which fatigability may be a prominent symptom. Only 46% of the patients initially assessed returned for the formal follow-up evaluation. Finally, we did not compare our patients with chronic fatigue to a control group ofmedical outpatients without this symptom. Nevertheless, this is the first prospective study to identify somatization disorder as a common psychiatric diagnosis in patients who complain of chronic fatigue. 393

Somatization Disorder and Chronic Fatigue

Although the life span of patients with somatization disorder is no shorter than that of the unaffected general population, their life is dominated by the polysymptomatic nature of their disease and the result is a clear-cut excess of medical care. 32- 35 Making accurate psychiatric diagnosis in these patients can be difficult and time-eonsuming. Use of structured psychiatric interviews and indices that screen for somatization disorder can facilitate this task,28.36 can im-

prove the efficiency ofdiagnosis, and can prevent lengthy workups, invasive diagnostic procedures, unnecessary surgery, and drug therapy that has little or no clinical benefit.

The authors thank Victor Hesse/brock, Ph.D., and Javier I. Escobar, M.D., for assistance during the planning and execution of this study and Patricia M. Crooks for manuscript preparation.

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