Primary care physicians encounter perplexing complaints in up to 40% of their patients.^1,2

Patients are often frustrated with troublesome symptoms that are inexplicable and refractory to multiple treatment regimens. Because there is variability in how patients present and no apparent cause for their symptoms, this clinical situation has historically been difficult to conceptualize, categorize, and treat effectively. A review of somatization in the primary care setting is germane to psychiatrists who function as consultants to primary care practitioners, since they are often asked to evaluate patients with somatoform disorders.

DIAGNOSTIC CONSIDERATIONS

Ancient Egyptian healers noticed that women were affected with perplexing somatic complaints more often than men and concluded that a "floating uterus" was the culprit. In the 17th century, Thomas Sydenham believed a multifactorial process that included "antecedent sorrows" should be considered for both men and women.³

Charcot—and then Freud—used the word "hysteria" to describe a condition they thought was largely based on unconscious emotional conflict with a related maladaptive somatic response. This term was commonly used until 1980, when the DSM-III changed the diagnosis to Briquet syndrome, in honor of the work done in this area by the 19th century French physician Paul Briquet. Currently, in primary care settings, the informal diagnosis of somatization is broadly used to describe patients with physical complaints that cannot be totally explained by physical examination and a corresponding diagnostic workup.

With a focus on the need to "exclude occult general medical conditions or substance-induced etiologies for the bodily symptoms," DSM IV⁴ includes 7 diagnoses under the category of somatoform disorders: somatization disorder, undifferentiated somatoform disorder, conversion disorder, pain disorder, hypochondriasis, body dysmorphic disorder, and somatoform disorder not otherwise specified (Table 1). It is important to note that the grouping of these disorders does not necessarily imply shared pathogenesis. The somatoform disorders are not fully explained by a general medical condition or other mental disorder and, in order to meet diagnostic criteria, must cause significant impairment or distress. Also, unlike a diagnosis of malingering or factitious disorder, patients with a somatoform disorder do not intentionally produce their symptoms.

Alternatives to the DSM-IV nomenclature have been suggested because of the perceived rigid diagnostic criteria, frequent overlap between the somatoform disorders, and the resultant impractical application to clinical practice. For example, in order to establish a DSM-IV diagnosis of somatization disorder, one must have 4 pain symptoms, 2 GI symptoms, 1 sexual symptom, and 1 pseudoneurologic symptom during the course of the illness. This somewhat arbitrary combination of symptoms is not always relevant to commonly encountered somatization in the primary care setting. Also, a person with a diagnosis of somatization disorder must have had multiple somatic complaints before the age of 30. However, studies have shown that patients are often unable to reliably recall their medical history with sufficient detail.⁵

The wide clinical spectrum of somatization has prompted some medical specialties to develop their own system to identify unexplained somatic symptoms. Some common examples include irritable bowel syndrome, chronic fatigue syndrome, and fibromyalgia. Because many patients do not meet full diagnostic criteria for somatization disorder, Escobar and colleagues⁶ introduced the abridged somatization disorder as a less restrictive alternative. This syndrome is based on lifetime symptoms and the presence of 4 somatic complaints in men and 6 in women. Several reports, including the World Health Organization Psychological Problems in General Health Care multicenter study, indicate high instability of recall when it comes to lifetime symptoms.⁵ In this study, 61% of unexplained somatic symptoms reported at baseline were not reported 1 year later. Multisomatoform disorder (MSD) is another diagnostic option for primary care patients with somatization that addresses this issue.⁷ Multisomatoform disorder is defined as the presence of 3 or more acutely distressful, medically unexplained symptoms from a checklist of 15 common symptoms found in the primary care setting (developed using the Primary Care Evaluation of Mental Disorders [PRIME-MD] scale that measures psychopathology⁷). Patients with MSD must have active symptoms with at least a 2-year history of somatization.

The differential diagnosis for somatization seen in the primary care setting is extensive. It is important to keep in mind that inexplicable illness can refer to a general medical condition, confirmation of which cannot be found, after a complete assessment, or it can explain a general medical condition that exists but medical evidence for which has not been discovered after a comprehensive workup. Lyme disease is an example of the latter. Before Lyme disease was discovered in 1982, children and adults were presenting with arthritis, myalgias, and fatigue with no known precipitant or cause. It is beyond the scope of this paper to discuss a full differential diagnosis for somatization, but it is important to do a complete diagnostic workup while considering somatization disorder a diagnosis of exclusion.

Before establishing a diagnosis of somatization disorder, one must attempt to rule out the intentional production of false physical or psychological symptoms. A patient in whom malingering is diagnosed is focused on feigning illness in an attempt to gain external incentives such as financial compensation, shelter, or escape from military duty or criminal prosecution. Factitious disorder also involves the purposeful and sometimes elaborate self-report of somatic complaints with the objective of assuming the "sick role." People with this disorder have no obvious external secondary gain beyond the sick role. When evaluating either condition, the physician should obtain collateral history (particularly from other area hospitals), complete a focused examination and, as with somatization disorder, consider both of them as diagnoses of exclusion.

CLINICAL SIGNIFICANCE

People with somatoform disorders experience high levels of physical discomfort and tend to be unsatisfied with life.⁸

A retrospective review of more than 13,000 psychiatric consultations found that somatization disorder resulted in more disability and unemployment than any other psychiatric illness.⁹ It is difficult to accurately establish the prevalence of somatization because of wide-ranging definitions and patients' limited ability to accurately recall symptoms from the distant past. Medical explanations for common somatic complaints, such as malaise, fatigue, abdominal discomfort, and dizziness, are found only 15% to 20% of the time.¹⁰ Somatization disorder has an estimated prevalence of 0.2% to 1.0% in primary care settings and is 5 times more common in women.⁶ The abridged somatization disorder has a higher prevalence in the primary care setting of about 20%.⁶ Multisomatoform disorder is uniquely based on current symptoms and is found in primary care patients 13% to 20% of the time.^11,12

Patients with somatization in the primary care setting have more than twice the outpatient utilization and overall medical care cost when compared with patients without somatization.¹³ This often translates into increased frustration and low levels of professional satisfaction for physicians who manage these patients.14 Part of the problem may be a lack of psychiatric supervision and instruction during residency training. Sullivan and associates¹⁵ surveyed 348 primary care program directors and found that two thirds of them believed more psychiatric education (particularly in the area of somatoform disorders) was needed for residents. Smith and coauthors¹⁶ showed that health care utilization and cost decreased by more than 50% when primary care physicians effectively treated their patients who had unexplained medical symptoms. An increase in training of primary care physicians in this area could result in improved job satisfaction and decreased patient morbidity.

	Table 1 Brief definitions of commonly used somatoform disorders4,6,7
	DSM-IV			Definition
	Somatization disorder			• Many unexplained physical complaints before age 30 • 4 pain, 2 GI, 1 sexual, 1 pseudoneurologic symptom(s)
	Undifferentiated somatoform disorder			• ≥1 unexplained physical complaint • Duration ≥ 6 months
	Conversion disorder			• ≥1 unexplainable, voluntary motor or sensory symptom or deficit • Directly preceded by a psychological stress
	Pain disorder			• Pain in ≥ 1 site that is largely caused by psychological factors
	Hypochondriasis			• Preoccupation with a nonexistent disease despite a thorough medical workup • Does not meet criteria for a delusion
	Body dysmorphic disorder			• Preoccupation with an imagined defect in physical appearance
	Somatoform disorder Not otherwise specified			• Somatoform symptoms that do not meet criteria for any specific somatoform disorder
Non–DSM-IV
	Abridged somatization disorder			• Presence of 4 unexplained somatic complaints in men and 6 in women • Long history of physical complaints
	Multisomatoform disorder			• ≥ 3 unexplained somatic complaints from the PRIME-MD scale • ≥ 2 years of active symptoms
PRIME-MD, Primary Care Evaluation of Mental Disorders. All above disorders: (1) cause significant social/occupational dysfunction, (2) are not caused by other general medical or psychiatric conditions, and (3) are not intentionally produced or related to secondary gain.