CHAPTER 60
Somatic Symptom Disorder
Michael Biglow, PharmD, BCPS, BCPP
Somatic symptom disorder (SSD) is a clinical syndrome characterized by the presence of multiple unexplained physical complaints without a known physical cause. This disorder is an important condition in primary care because it is responsible for unnecessary diagnostic testing and therapeutic interventions. It is well known in primary care that patients express emotional or psychological symptoms physically and respond to these symptoms differently. Another barrier to care is in determination of the motivation for the patient seeking care, as SSD is commonly misinterpreted as malingering where patients will falsify or grossly exaggerate physical symptoms for financial or social gain.
The most recent edition of the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) has modified the diagnostic criteria and changed the title (of somatization disorder) to SSD. To be diagnosed, patients must be symptomatic, for at least 6 months (American Psychiatric Association [APA], 2014).
Somatization can be seen as one end of a continuum in which physical complaints are perceived to be incapacitating, either because of the patient’s preoccupation with the symptoms or because the experience of the symptoms is intense. For these patients, somatic complaints tend to be more debilitating, involve a greater number of clusters of complaints, and occur over a longer period of time. At the other end of the continuum are patients who describe what has been called symptom sensitivity. These patients are acutely aware of the presence of physical symptoms to a greater degree than many other patients.
Patients with SSD tend to have a greater-than-expected degree of disability from their complaints. In some cases, what appear to be minor complaints may cause such psychological distress that social or occupational functioning is compromised, seriously affecting their quality of life. The diagnosis of SSD must be made carefully to exclude underlying physical conditions that have not been diagnosed. Often years of medical records need to be reviewed to ensure that adequate testing has been undertaken to exclude physical complaints. Thorough attention must be paid to atypical presentations of common illnesses and to rarer illnesses. Treatment involves the development of a therapeutic relationship over an extended period of time, one in which patients feel that their complaints are taken seriously. Often, the development of a therapeutic relationship is troubled by doubt and frustration by both the patient and the provider. It is important that while this relationship is forming, the primary care provider maintains an open, nonjudgmental, and caring demeanor.
ANATOMY, PHYSIOLOGY, AND PATHOLOGY
As with many illnesses, there appears to be a strong familial link in SSD. It is unknown whether this is the result of environmental or genetic influences. For example, some families may sanction the expression of physical complaints to a greater degree than other families. Sexual abuse has been found to be associated with a high rate of SSD in women but it is not always the case that a patient with a history of sexual abuse will develop SSD (Paras et al., 2009).
In SSD, physical complaints are presented without adequate physical findings. This lack of presence of an organic pathology can be frustrating to even the most experienced primary care provider. There is little if any match between the symptoms and the actual physical findings (Barsky, 2013).
EPIDEMIOLOGY
Much has been written about the social, gender, and situation influences on SSD; it has been found to be expressed differently in different cultural groups. It is thought to have a much higher prevalence among women than men. In general, the 12-month prevalence in the general population is 6% and, given the new diagnostic criteria, an overall prevalence of 5% to 7% (APA, 2013; Wittchen & Jacobi, 2005). However, rates of SSD vary greatly depending on the population studied, the definition of the syndrome, and the practice setting (Creed & Barksey, 2004).
Some research has suggested that environmental factors may play a role in the expression of SSD. Also described as “multiple chemical sensitivity,” certain environmental factors, such as exposure to certain chemicals, are thought to cause or aggravate physical complaints. In cases of this environmental somatization syndrome, no cause can be found for these physical complaints based on the suspicious agent. An example of this syndrome is the association of disease or illness with office buildings. Although there are no obvious environmental or physical causes for these beliefs, groups of people may come to see the building itself as the cause of this syndrome. In addition, patients tend to downplay the importance of other explanations for the cause of their symptoms. Patients become convinced that the facility is to blame for their illness and often refuse suggestions that other factors, such as stress or tobacco use, may be involved (Spencer & Schur, 2008).
It is thought that because different social groups may sanction the expression of physical complaints through different symptoms, there is likely to be a large cultural component to the expression of SSD. For example, common somatic complaints included heat radiating from the head, generalized aches and pains, crawling sensations, headache, excessive gas, chest pain, and gynecological complaints, according to cultural background. Cultural concerns are primary in any health-related assessment, or plan of care (Spector, 2013).
DIAGNOSTIC CRITERIA
In order to better emphasize the prescience of physical symptoms and signs versus the lack of a medical explanation, the DSM-5 reclassified and renamed somatization disorder, SSD (Table 60.1). Although the criteria for diagnosis are widely accepted and were formed by consensus (APA, 2013), other researchers often use lower symptom thresholds to determine the number of patients within a population with somatization tendencies.
Other aspects to be specified during the diagnostic evaluation include the presence of pain as well as severity, which is classified as either mild, moderate, or severe depending on the number of symptoms specified in Criterion B that are fulfilled.
