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Fibromyalgia and Psychopathology in a Community Hospital Emergency Room

P. Waverly Davidson III, MD, FACP

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Primary Psychiatry. 2003;10(3):69-73

 

Dr. Davidson is clinical professor of psychiatry and behavioral sciences in the Department of Psychiatry at the University of Southern California School of Medicine, and consulting psychiatrist at the Pacific Hospital of Long Beach Outpatient Psychiatric Clinic, in Long Beach California.

Disclosure: The author reports no financial, academic, or other support was received for this work.

Please direct all correspondence to: P. Waverly Davidson, MD, PO Box 15778; Beverly Hills, CA 90929.



Abstract

Objective: Using a retrospective chart review, the authors investigated the rate of occurrence of primary and posttraumatic fibromyalgia among 204 patients being assessed for pain management at a community hospital emergency room (ER). The presence of psychopathology was investigated as well.

Background: The relevant medical literature was summarized in regard to the comorbidity of fibromyalgia and depressive disorders, the comorbidity of fibromyalgia and somatoform disorders, and the comorbidity of fibromyalgia and other neurologic and medical syndromes.

Methods: This study was conducted at Pacific Hospital of Long Beach, CA. The author reviewed 204 charts of patients with musculoskeletal pains who were assessed in the ER between July 1999 and March 2001, 10 of whom had been previously diagnosed with fibromyalgia.

Results: Although fibromyalgia constitutes 20% to 30% of a typical rheumatologist’s practice, only 5% of the ER patients were diagnosed with the condition. As was summarized in the literature review, there were multiple psychiatric diagnoses in the 10 fibromyalgia patients, as well as disabilities, multiple outpatient psychiatric treatments, and use of analgesics and psychotropic medications. All 10 patients were receiving some form of monetary compensation and none were currently employed.

Conclusion: It would appear that fibromyalgia is a somatoform disorder more aptly described as a “multisomatoform disorder” because of the basic symptoms of widespread musculoskeletal pain, fatigue, tender points on physical examination, and due to its association with victimization attitudes, family history of alcoholism, depression, or somatization, childhood sexual abuse, and association with certain neurologic syndromes such as carpel tunnel syndrome, chronic fatigue syndrome, work absenteeism, and disability.

Discussion: Guidelines to help primary care physicians distinguish which acute fibromyalgia patients are likely to become chronic fibromyalgia patients are presented, followed by guidelines for future investigations into the psychopathology associated with fibromyalgia.

 

Introduction

Fibromyalgia is a common, complex, chronic, and controversial condition of unestablished etiology,1 that is characterized by widespread musculoskeletal pain, multiple tender pressure points, and profound fatigue. Although the condition is distinct from articular joint disease, ironically it is referred to as “rheumatism of the muscles.” The condition may be associated with other syndromes of uncertain etiology such as chronic fatigue syndrome (CFS), irritable bowel syndrome (IBS), and carpel tunnel syndrome (CTS), and is often accompanied by headaches, insomnia, depression, and exhaustion.

This study is a retrospective chart review investigating the occurrence rate of fibromyalgia among patients assessed for pain management in the emergency room (ER) of a general hospital. The study also investigates the comorbid psychopathology of fibromyalgia patients, which can help primary care physicians better treat such patients or know when to refer them to specialists.

 

Background

Ayd2 found that fibromyalgia had an estimated prevalence of 15% to 20% in rheumatology clinics and is the most common cause of widespread chronic pain. The estimated prevalence of fibromyalgia in the general community is 2% for both sexes; 3.4% for women and 0.5% for men.3,4 Marden and colleagues5 pointed out that fibromyalgia is the second most common diagnosis in American rheumatology clinics, while Schultes and colleagues6 indicated that 1% to 7% of the German population suffer from fibromyalgia. According to Hadler,7 20% of Americans awaken frequently with “morning stiffness” lasting as along as 30 minutes and seek no medical attention at all. In pointing out the difficulty of determining the presence of focal “tender points,” Sola and colleagues8 reported that 50% of their patients can be made to be aware of such tender points during a physical exam, especially of the pectoral girtle muscles, and still be in robust good health.

In the past, a wide spectrum of chronic and subchronic musculoskeletal conditions had been commonly called “fibrositis.”9 In 1990, based on a multi-center study,10 the American College of Rheumatology (ACR) set the criteria for the classification and diagnosis for the favored, more descriptive term, “fibromyalgia.” At present, the diagnosis of fibromyalgia must include the finding of widespread, chronic musculoskeletal pain, and mild (or greater) tenderness in at least 11 of 18 specified tender points located by digital palpation.11

In a study by Andersson and colleagues,12 22% of 1,609 Swedes with widespread pain of >3 months’ duration fit the ACR criteria for fibromyalgia. However, the 78% who did not fulfill the fibromyalgia criteria had similar profiles to the group with fibromyalgia in regard to fibromyalgia spectrum of problems, including depression, anxiety, work, absenteeism, and pain intensity.

In terms of prognosis, McFarlane and colleagues13 studied 141 English men and women in Manchester and found that only 35% of their subjects with chronic widespread pain still had pain 2 years later. Thus they speculated that most fibromyalgia patients who do not receive treatment for their symptoms, tend to make spontaneous recoveries. How then, can a primary care physician predict which fibromyalgia patients will improve with little or no treatment and which ones will need specialized rheumatological care?

 

Posttraumatic Fibromyalgia

Before the ACR published their report in 1990, the terms “fibrositis” and “fibromyalgia” were used interchangeably.10 The term “primary fibromyalgia” was introduced when describing a patient without any other medical disorder or disease that could affect fibromyalgia symptoms; the terms “secondary fibromyalgia” or “concomitant fibromyalgia” was used when other medical disorders or diseases were also present. The multicenter committee of the ACR which had devised the two terms, then disavowed the existence of any significant clinical difference between the two. The term “posttraumatic fibromyalgia” (PT fibromyalgia) refers to the fibromyalgia symptoms present which have arisen only after trauma (usually motor vehicular accidents), and are not synonymous with “secondary fibromyalgia.”

Nielsen and Merskey14 reported that the diagnosis of PT fibromyalgia has not been adequately validated and that reports of high rates of PT fibromyalgia among those fibromyalgia patients are not well designed and are often derived from uncontrolled studies. In contrast, Buskila and colleagues,15 in a well-designed study, reported 102 patients with nonspecific soft tissue neck injuries, 90% of whom had classical “whiplash” symptoms, and compared the occurrence of PT fibromyalgia in these patients with the occurrence of PT fibromyalgia in 59 patients with leg fractures. They offered no clear explanation as to why there was a higher prevalence of PT fibromyalgia (21.7%) in the neck injury patients, but only a prevalence of 1.7% of PT fibromyalgia in the more severely injured leg fracture patients, after 12.4 months from the time of injury.

Turk and colleagues16 described three distinct profiles of fibromyalgia patients: dysfunctional, interpersonally distressed, and adaptive copers. In a second study by Turk and colleauges,17 the researchers explored the differences between PT fibromyalgia patients and fibromyalgia patients, with 46 patients in each diagnostic category matched for age and duration of pain. While they found that the PT fibromyalgia patients used more narcotic analgesics, more nerve blocks, more transcutaneous electric nerve stimulator units, more physical therapy, and were more likely to fall into the “dysfunctional” and interpersonally distressed” profiles, the fibromyalgia patients were more often classified as “adaptive copers.” There were no significant differences between the two groups in terms of legal-financial incentive, suggesting that the PT fibromyalgia patients were not merely seeking monetary gains, but perhaps indicating that these PT fibromyalgia patients had more subconscious unmet needs, as in the psychodynamics of somatoform disorders.

 

Comorbidity of Fibromyalgia and Depression

Goldenberg and Don18 administered the Diagnostic Interview Schedule (DIS) to 31 fibromyalgia patients at the Newton-Wellsley Hospital in Boston, using 14 patients with rheumatoid arthritis as controls. In 1989, this was the first time that a structured interview using criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition19 was used with fibromyalgia patients. When the researchers expanded their fibromyalgia patient pool from 31 to 82, they found that 60% had a lifetime history of major depression and 21% had current major depression, in contrast to the current rate of 8.7% in the rheumatoid arthritis group. However, 3 years later, Ahles and colleagues20 and Yunus and colleagues21 made similar studies and did not find significant difference in major depression between groups of patients with fibromyalgia and rheumatoid arthritis.

In a 1999 study22 involving four tertiary care centers in Washington, DC, San Diego, CA, Stonybrook, NY, and Charleston, SC, 73 patients were evaluated for major depression based on criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)23 using the Structured Clinical Interview, the Raad 36-Item Health Survey, and multiple self-report measures. The fibromyalgia patients were found to have a high lifetime prevalence and current incidence of major depression (68% and 22%, respectively). In addition, 16% had a lifetime prevalence of panic disorder as well as a 7% incidence of current panic disorder.

Katz and Krabitz24 evaluated 425 first-degree relatives of 55 females and 5 males with fibromyalgia and concluded that there was a subgroup of fibromyalgia patients with major depression, whose family members had both depression and alcoholism, and who were more likely to have had an abusive childhood as a result of this family dysfunction. This theme of physical and emotional abuse and neglect is also reported by Van Houdenhove and colleagues,25 who showed a higher prevalence of abuse in 96 patients with fibromyalgia and CFS compared with two other control groups—a chronic disease group and a healthy group.

 

Comorbidity of Fibromyalgia and Somatoform Disorders

Kirmayer and colleagues26 studied 20 fibromyalgia patients and 23 rheumatoid arthritis controls and found no significant difference in current or lifetime depression. While they did not conclude, as other investigators did, that fibromyalgia was a type of somatized depression, they did report that the fibromyalgia patients had “more somatic symptoms of obscure origin,” had more numerous somatic complaints, had endured more surgical procedures, and had sought medical help more frequently.

In 1991, Maccrocchi27 reported a case of conversion disorder presenting as fibromyalgia in which he was able to trace the fibromyalgia symptoms to specific psychological trauma. He speculated that his case, unlike those of classical conversion disorder, wherein psychological events lead to neurologic symptoms, had shown that psychological events had led to fibromyalgia symptoms.

Kroenke and colleagues28 have also noted that fibromyalgia patients are not classical cases of somatization disorder, but have proposed that a new disorder be added to the spectrum of DSM-IV somatoform disorders; this new disorder, to be called “multisomatoform disorder,” would fall between “full” and “abridged” somatization criteria, and would include functional impairment, psychiatric comorbidity, family dysfunction, and health care utilization costs. He opined that fibromyalgia would be properly included in this new multisomatoform designation.

McBeth and colleagues29 completed a prospective population-based study of 1,658 adults, using the General Health Questionnaire, the Somatic Symptom Checklist, the Fatigue Questionnaire, and the Illness Attitude Scale. Half of his subjects were pain-free and half had pain symptoms, but not widespread or chronic pain. At 1-year follow-up, 825 subjects with pain were re-evaluated, and it was found that 8% of these individuals, who had displayed many aspects of somatization earlier, were the ones who developed widespread chronic pain, a cardinal symptom of fibromyalgia.

 

Comorbidity of Fibromyalgia and Other Disorders

Sleep disturbances, tension headaches, and migraine headaches occur commonly in fibromyalgia patients. Malt and colleagues30 reported that 27% of 45 female patients studied had lifetime prevalence of panic disorder. Sivri and colleagues31 reported that 42% of IBS patients had fibromyalgia, whereas Veale and colleagues32 reported a much higher occurrence (65%) of fibromyalgia among IBS patients. Yunus and Aldag33 reported restless legs syndrome in 31% of fibromyalgia patients compared to 15% in rheumatoid arthritis patients and 2% in control subjects. Andreu and colleagues34 reported that CTS is common in fibromyalgia patients, but that fibromyalgia was very rare in the 102 CTS patients he studied. Dohrenbusch and Gruterich35 reported an association between fibromyalgia and Sjogren’s syndrome.

 

Method

The purpose of this study was to determine the rates of patients diagnosed with primary fibromyalgia and with PR fibromyalgia occurring in a community hospital ER by use of a retrospective chart review, and to determine the nature of any psychopathology co-occurring in these patients.

Pacific Hospital of Long Beach, CA, is a full-service 171-bed hospital with a 24-hour ER. Between July 1999 and March 2001, 204 individuals presented themselves to the ER with the International Classification of Diseases, Ninth Edition diagnostic code of 729.1.36 This code covers the following categories: unspecified myalgia and myositis, fibromyositis, and fibromyositis not otherwise specified. The charts of these 204 patients were reviewed to determine which among them were diagnosed with fibromyalgia or PT fibromyalgia and to determine if any psychopathology was present in the fibromyalgia and PT fibromyalgia patients.

Many of the 204 patients had made multiple presentations to the ER for treatment of their pain symptoms so that the total number of ER visits was 309.

 

Results

Of the 204 patients, 22 had musculoskeletal chest pains for which cardiac pathology was ruled out. Nevertheless, these 22 charts had been retrieved with the 729.1 diagnostic code. Thirteen patients presented with myositis as a result of a motor vehicular accident or a slip-and-fall accident; 40 patients had musculoskeletal pains or myositis in addition to acute panic episodes with hyperventilation symptoms; 43 patients were acutely intoxicated with alcohol and/or drugs and had minor lacerations in addition to painful musculoskeletal soft tissue injuries or myositis directly related to their intoxication; 76 patients had various types of musculoskeletal pains associated with osteoarthritis, lower back pain, disc disease, migraine headaches, or other forms of myositis, and had previously been diagnosed with a major mental illness such as schizoaffective disorder, schizophrenia, bipolar disorder, or major unipolar depression. Ten patients, representing 5% of the total group, had been previously diagnosed as having fibromyalgia prior to their visits to the ER.

Of the 10 fibromyalgia patients whose charts were retrieved, 8 were female (average age=49 years) and 2 were male (ages 56 and 31). Both males and two of the females had been diagnosed with PT fibromyalgia. Of the six females with primary fibromyalgia, three had comorbid diagnoses for generalized anxiety disorder, four had been also diagnosed with minor depression, and one was diagnosed with current drug addiction and had been previously diagnosed with schizoaffective disorder. Three females had lifetime histories of alcohol or drug addiction; two females had diagnoses of temporomandibular joint syndrome; one female was also diagnosed with IBS.

A careful new chart review of the 10 fibromyalgia patients showed that all patients with PT fibromyalgia (two males and two females) were currently receiving social security disability benefits or workers’ compensation benefits; one of the males had received five epidural blocks for his fibromyalgia during the 21 months of the study. The schizoaffective female had two inpatient psychiatric hospitalizations during the study. Two of the six females with primary fibromyalgia had previous treatments for CTS and four primary fibromyalgia females had been treated for their comorbid psychopathology with a total of 15 outpatient psychiatric clinic visits in addition to their ER visits during the time frame of the study.

All eight females were treated with analgesics for their fibromyalgia or PT fibromyalgia symptoms and psychotropic medications for their psychiatric symptoms; the two males were receiving analgesic medications for their PT fibromyalgia symptoms. In addition to the four patients receiving some form of monetary compensation or benefits on the basis of their PT fibromyalgia symptoms, all of the remaining six primary fibromyalgia females were also recipients of monetary benefits, based not just on primary fibromyalgia alone, but on the totality of their several comorbid diagnoses as well.

 

Discussion

One of the 2-fold purposes of this study was to investigate the rate of occurrence of fibromyalgia among patients assessed for pain management in a community hospital ER. With a retrospective chart review of 204 patients over a 21-month period, 5% had been diagnosed with fibromyalgia. If patients with fibromyalgia constitute 20% to 30% of the clinical practice of some rheumatologists, it would appear that they present themselves to local ER only for pain management and not for diagnoses.

Due to the comorbidity of so many varying neurologic syndromes and psychiatric conditions, one can begin to understand the controversy that often surrounds the validity of the diagnosis of this chronic widespread pain syndrome. It is because of this comorbidity and chronicity that so many fibromyalgia patients seek the emotional support of fibromyalgia self-help groups, fibromyalgia advocacy groups, and more sympathetic rheumatologists.37-41 It can also be speculated that fibromyalgia patients who do not feel that they get adequate management for their symptoms turn to the ERs for pain relief. Many turn to litigation as well, making inadequate medical treatment a financial burden on the population at large; it is estimated that $10 billion is spent annually in America on health care for the 6 million fibromyalgia patients, including litigation costs.42,43

All 10 of the fibromyalgia patients whose charts were reviewed in this study (96 primary fibromyalgia and 4 PT fibromyalgia patients) were receiving monetary benefits.

 

Conclusion

It is clear that a wide range of psychopathology existed in the background of these 10 patients, perhaps in their families as well, and in the multiple neurologic and psychiatric diagnoses most of them have in addition to the fibromyalgia /PT fibromyalgia.

Fibromyalgia was described in the early 1880s but it only recently emerged as a distinct syndrome in 1990 when fibromyositis was renamed by a committee of the American College of Rheumatology. Seven of the 10 patients (70%) reported here who habitually use a local ER for pain flare-ups but who report to rheumatologists or primary care physicians for diagnostic validation of their symptoms, have either a current or lifetime comorbidity for psychiatric diagnoses, mostly depression. This percentage is comparable with that of Goldenberg and Don,11,18 Crook and colleagues,44 and Granges and colleagues.45

There seems to be a subgroup of fibromyalgia patients prone to depression themselves, with family histories of depression, as reported in the studies by Epstein and colleagues22 and Katz and Krabitz.24 There are other fibromyalgia subgroups with CFS, IBS, sleep disturbances, restless legs syndromes, and other disorders.

Since both patients with depression and those with fibromyalgia respond often to antidepressants, there is a tendency to link them in terms of causation. However, most fibromyalgia patients seen in rheumatology clinics do not have treatable major depression nor are they seeking treatment for depression from their rheumatologists. Thus, Ayr2 referred to an Iowa study reporting that “fibromyalgia has been associated with anxiety and depression in 50% to 90% of patients seeking treatment for fibromyalgia.” There is no suggestion that these fibromyalgia patients also sought treatment for their depression, but they may have reported depressive symptoms when asked about their lifetime experience.

The question of somatization is an important one in terms of prognosis, as noted by the studies of Kirmayer and colleagues,26 Macciocchi,27 Kroenke and colleagues,28 and McBeth and Selman,46 which note that the more likely it is that the basic symptoms of fibromyalgia (widespread musculoskeletal pain, fatigues, and tender points) are associated with work, absenteeism, disability, victimization attitudes, psychiatric comorbidity, family history of alcoholism, depression or somatization, childhood sexual abuse, and/or neurological syndromes (such as CTS, degenerative disc disease, or migraine headaches), the more likely it is that those fibromyalgia symptoms will become chronic. This seems to be true for both primary fibromyalgia and PT fibromyalgia.

In addition, it it noted that once the fibromyalgia symptoms have become chronic, it is more likely that those fibromyalgia patients will be referred to rheumatologists. It is also more likely that their symptoms will fit into the multisomatoform disorder (MSD)described by Kroenke and colleagues28 in 1998, when they combined data from two studies (N=1,258) and proposed that MSD was an intermediate diagnosis between the abridged and full somatization disorder. The MSD?diagnosis included a patient’s disabilities, comorbid psychiatric diagnosis, family dysfunction, and use of health care facilities.

Guided by these insights, the primary care physician can more quickly predict which fibromyalgia patients will become pain-free with only the “morning stiffness” that Hadler7 describes, and which patients will require rheumatologists and/or psychiatrists for longer periods of care and pain management.

Future investigators should compare primary and PT fibromyalgia patients being currently treated for their comorbid psychiatric disorders, and those being treated in rheumatology clinics who are not in current psychiatric treatment (even though some psychiatric symptoms may be present), with matched groups of nonpatients in the community who were treated for primary or PT fibromyalgia in the past (including subgroups of patients who had and who did not have psychiatric disorders in the past) but who have completely recovered.

There should also be two distinct control groups: healthy individuals matched for age and gender with the other groups, who have never experienced any treatment for psychiatric symptoms or any pain syndromes, and another group of individuals, also age and gender matched, who currently or in the past have had painful musculoskeletal diseases other than primary fibromyalgia or PT fibromyalgia. Family history, various psychological tests, and pain inventory tests, should be obtained on all groups in such an extensive retrospective and prospective study. PP

 

References

1. Carette J, Bell MJ, Reynolds WJ, et al. Comparison of amitriptyline, cyclobezaprine, and placebo in the treatment of fibromyalgia: a randomized double-blind clinical trial. Arthritis Rheum. 1994;37:32-40.

2. Ayd FJ Jr. 1998 American Psychiatric Association Report. Psychiatr Times. 1998;8:4.

3. Wolfe F, Toss K, Anderson J, Russell IJ, Hebert L. The prevalence and characteristics of fibromaylgia in the general population. Arthritis Rheum. 1995;1:19-28.

4. Croft P, Schollum J, Silman A. Population study of tender point counts and pain as evidence of fibromyalgia in the general population. BMJ. 1994;6956:696-699.

5. Marden WD, Meenan RF, Felson DT, et al. The present and future adequacy of rheumatology manpower: a study of health care needs and physician supply. Arthritis Rheum. 1991;10:1209-1217.

6. Schultes H, Pirk O, Berger K, Schramm B, Pongratz D. Cost of illness in fibromyalgia: results of a feasibility study. Abstract presented at: 64th Annual Meeting of the American College of Rheumatology; May 2000; Neurenberg, Germany.

7. Hadler NM. Occupational Musculoskeletal Disorders. 2nd ed. Philadelphia, Pa: Lippincott Williams and Wilkins; 1999.

8. Sola AE, Rodenberger ML, Gettys BB. Incidence of hypersensitive areas in posterior shoulder muscles. Am J Phys Med. 1955;34:585-590.

9. Hudson JI, Hudson MS, Pliner LF, Goldenberg DL, Pope HG Jr. Fibromyalgia and major affective disorders: a controlled phenomenology and family history study. Am J Psychiatry. 1985;4:441-446.

10. Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia: Report of the Multicenter Criteria Committee. Arthritis Rheum. 1990;2:160-172.

11. Goldenberg DL. Fibromyalgia syndrome a decade later: what have we learned? Arch Intern Med. 1999;8:777-785.

12. Andersson H, Ejlertsson G, Leden I, Rosenberg C. Characteristics of subjects with chronic pain, in relation to local and widespread pain reports. Scand J Rheumatol. 1996;3:146-154.

13. MacFarlane GJ, Thomas E, Papageiorgiou AC, Schollum J, Croft PR, Silman AJ. The natural history of chronic pain in the community: a better prognosis than in the clinic? J Rheumatol. 1966;9:1617-1620.

14. Nielsen WR, Merskey H. Psychosocial aspects of fibromyalgia. Curr Pain Headache Rep. 2001;4:330-337.

15. Buskila D, Neumann L, Vaisberg G, Alkalay D, Wolfe F. Increased rates of fibromyalgia following cervical spine injury: a controlled study of 161 cases of traumatic injury. Arthritis Rheum. 1997;3:446-452.

16. Turk DC, Okifuji A, Sinclair JD, Starz TW. Pain, disability, and physical functioning in subgroups of patients with fibromyalgia. J Rheumatol. 1996;7:1255-1262.

17. Turk DC, Okifuji A, Starz TW, Sinclair JD. Effects of type of symptom onset on psychological distress and disability in fibromyalgia syndrome patients. Pain. 1996;2-3:423-430.

18. Goldenberg DL. Psychiatric and Psychological Aspects of the Fibromyalgia Syndrome. Vol 15. Newton, MA: Arthritis-Fibrositis Center, Newton-Wellesley Hospital; 2000:105-114.

19.Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington, DC: American Psychiatric Assocation; 1980.

20. Ahles TA, Khan SA, Yunus MB, Spiegel DA, Masi AT. Psychiatric status of patients with primary fibromyalgia, patients with rheumatoid arthritis, and subjects without pain: a blind comparison of DSM-III diagnoses. Am J Psychiatry. 1991;12:1721-1726.

21. Yunus MB, Ahles TA, Aldag JC, Masi AT. Relationship of clinical features with psychological status in primary fibromyalgia. Arthritis Rheum. 1991;1:15-21.

22. Epstein SA, Kay G, Clauw D, et al. Psychiatric disorders in patients with fibromyalgia: a multicenter investigation. Psychosomatics. 1999;1:57-63.

23.Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.

24. Katz RS, Kravitz HM. Fibromyalgia, common depression, and alcoholism: a family history study. J Rheumatol. 1996;1:149-154.

25. Van Houdenhove B, Neerinckx E, Lysens R. Victimization in chronic fatigue syndrome and fibromyalgia patients in tertiary care: a controlled study on prevalence and characteristics. Psychosomatics. 2001;1:21-28.

26. Kirmayer LJ, Robbins JM, Kapusta MA. Somatization and depression in fibromyalgia syndrome. Am J Psychiatry. 1988;8:950-954.

27. Macciocchi SN. Conversion disorder presenting as primary fibromyalgia. Psychosomatics. 1993;3:267-270.

28. Kroenke K, Spitzer RL, deGruy FV, Swindle R. A symptom checklist to screen for somatoform disorders in primary care. Psychosomatics. 1998;3:263-272.

29. McBeth J, McFarlane GJ, Benjamin S, Silman AJ. Features of somatization predict the onset of chronic widespread pain: results of a large population-based study. Arthritis Rheum. 2001;4:940-946.

30. Malt EA, Berle JE, Olafsson S, Lund A, Ursin H. Fibromyalgia is associated with pain disorders and functional dyspepsia with mood disorders: a study of women with random sample population controls. J Psychosom Res. 2000;5:285-289.

31. Sivri A, Cindas A, Dincer F, Sivri B. Irritable bowel syndrome. Clin Rheumatol. 1996;3:283-286.

32. Veale D, Kavanagh G, Fielding JF, Fitzgerald O. Primary fibromyalgia and the irritable bowel syndrome: different expressions of a common pathogenic process. Br J Rheumatol. 1991;3:220-222.

33. Yunus MD, Aldag JC. Restless legs syndrome and leg cramps in fibromyalgia syndrome: a controlled study. Br Med J. 1996;312:1339-1341.

34. Andreu JL, Ly-Pen D, deBias G, Sanchey-Olaso A. Prevalence of fibromyalgia in patients with carpel tunnel syndrome: a prospective primary case based study. Abstract presented at: the 64th Annual Meeting of the College of Rheumatology; May 2000; Neurenberg, Germany.

35. Dohrenbusch R, Gruterich M, Genth Z. Fibromyalgia and sjogren’s syndromes: clinical and methodological aspects. Rheumatology. 1996;55:19-27.

36. American Medical Association. International Classification of Diseases. 9th ed. Jones MK, ed. N. Valley City, UT: INGENIX Press; 2001.

37. McIlwain H, Bruce DF. The Fibromyalgia Handbook. New York, NY: Henry Holt & Co.; 1996.

38. Fransen J, Russell IJ. The Fibromyalgia Helpbook.St. Paul, MN: Smith House Press; 1996.

39. Starlanyl D, Copeland ME. Fibromyalgia and Chronic Myofascial Pain Syndrome. Oakland, CA: New Harbinger Publications; 1996.

40. Starlanyl D. The Fibromyalgia Advocate. Oakland, CA: New Harbinger Publishers; 1998.

41. Amand RP, Marek CC. What Your Doctor May Not Tell You About Fibromyalgia. Boston, MA:?Little, Brown, and Co.; 1999.

42. Aronoff GM, Markovitz A. AADEP position paper: fibromyalgia impairment and disability issues. Disability. 1998;8:1-10.

43. Wallace DJ, Hallegua DS. Quality of life, legal-financial, and disability issues in fibromyalgia. Curr Pain Head Rep. 2001;5:313-319.

44. Crook J, Weir R, Tunks E. An epidemiological follow-up survey of persistent pain sufferers in a family group practice and specialty pain clinic. Pain. 1989;36:49-61.

45. Granges G, Zilko P, Littlejohn G. Fibromyalgia syndrome assessment of the severity of the condition 2 years after diagnosis. J Rheumatol. 1994;21:523-529.