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Gordon J. G. Asmundson and Daniel M. LeBouthillier

Description of the Disorders

The somatic symptom and related disorders were introduced in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5; American Psychiatric Association [APA], 2013) and replaced the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR; APA, 2000) somatoform disorders. Changes were made in an effort to eliminate overlap and clarify boundaries between diagnosable disorders and to recognize that people meeting diagnostic criteria for one of these disorders may or may not have an identifiable medical condition; however, as noted later, there is continuing debate as to the validity of the changes made. The somatic symptom and related disorders include somatic symptom disorder, illness anxiety disorder, conversion disorder (functional neurological symptom disorder), psychological factors affecting other medical conditions, factitious disorder, other specified somatic symptom and related disorder, and unspecified somatic symptom and related disorder.

Specific Disorders

The common feature of the somatic symptom and related disorders is prominent somatic sensations (e.g., dyspnea, pain) or changes (e.g., subcutaneous lumps, rash)—called “symptoms” in DSM-5 terminology—that are associated with significant emotional distress and functional impairment and often interpreted by the person as being symptomatic of some disease process or physical anomaly. Bodily sensations and changes are a ubiquitous experience, and they typically remit without medical attention; however, about 25% of the population seeks medical attention when these sensations and changes persist (Kroenke, 2003). Up to 30% of those seeking medical attention will exhibit clinically significant distress about having an unidentified disease when there is no medical explanation for presenting “symptoms” (Fink, Sørensen, Engberg, Holm, & Munk-Jørgensen, 1999); yet many remain distressed despite identifiable medical explanation (APA, 2013; Taylor & Asmundson, 2004). This distress is associated with substantial impairment of personal, social, and professional functioning as well as considerable costs to health care (Hessel, Geyer, Hinz, & Brahier, 2005), even after controlling for medical and psychiatric comorbidity (Barsky, Orav, & Bates, 2005).

Despite the prevalence and cost of distressing somatic sensations and changes, as well as a substantive increase in empirical attention during the past decade, understanding of their presentation remains limited. Likewise, although there are some data on the validity, reliability, and clinical utility of the diagnoses of somatic symptom disorder and illness anxiety disorder (Bailer et al., 2016; Dimsdale et al., 2013; van Dessel, van der Wouden, Dekker, & van der Horst, 2016), there have been few studies on the diagnostic category as a whole. In the sections that follow, we provide an overview of the general clinical profile, diagnostic considerations, and epidemiology of the somatic symptom and related disorders. Assessment, etiological considerations, and course and prognosis are also considered. In each of these latter sections, we touch on issues germane to the collective category as well as its specific disorders. In the case study, we focus more specifically on an illustration of uncomplicated somatic symptom disorder. There are currently few data on epidemiology, etiology, course, prognosis, assessment, or treatment of the somatic symptom and related disorders; therefore, much of the data presented below are borrowed from pre-DSM-5 knowledge of related conditions and disorders.

Clinical Picture

The clinical profile for each somatic symptom and related disorder is unique, although each disorder is predicated on the prominence of somatic sensations or changes associated with distress and impairment. A brief overview of the clinical profile of each somatic symptom disorder is provided, along with reference to DSM-5 diagnostic criteria.

Somatic Symptom Disorder

Somatic symptom disorder is the cornerstone diagnosis of the somatic symptom and related disorders category. The main feature of somatic symptom disorder is the presence of one or more somatic symptoms or features that cause distress and impairment in daily living (criterion A). The concern ranges from highly specific (e.g., “This pain in my gut is so bad. I must have stomach cancer”) to vague and diffuse (e.g., “My whole body is aching. What could it be? Maybe it's ALS”). Individuals with somatic symptom disorder exhibit excessive thoughts, feelings, or behaviors related to their somatic symptoms (criterion B). An individual meets criterion B if he or she: (a) exhibits disproportionate thoughts about the seriousness of their symptoms, (b) experiences persistently high levels of anxiety regarding their symptoms or about their health, or (c) devotes an excessive amount of time to their health (e.g., seeking reassurance from health professionals, doing research about their somatic sensations or changes, perusing body parts to find potential lumps). Excessive somatic concerns must persist for at least 6 months (criterion C), although somatic symptoms do not need to be present for this entire period. Individuals with somatic symptom disorder may often resist the idea that they are suffering from a mental health disorder and may come to rely on reassurance-seeking (e.g., deriving comfort from assurances by significant others that everything is okay) and checking behaviors (e.g., palpating subcutaneous lumps, searching for information about disease in medical textbooks and on the Internet) to placate concerns about having a serious disease. Although these behaviors can be effective in providing short-term relief, they perpetuate the condition in the long term (Taylor & Asmundson, 2004).

There are several diagnostic specifiers that can accompany somatic symptom disorder. When somatic complaints revolve largely around pain, the “with predominant pain” specifier can be applied. This specifier replaces the pain disorder diagnosis from DSM-IV. The persistent specifier applies in cases where severe symptoms and impairment last for longer than 6 months. Finally, severity can be specified as mild, moderate, or severe when an individual meets one, two, or three of the criterion B symptoms, respectively. For example, a moderate severity specifier is assigned to an individual who reports debilitating anxiety due to bodily symptoms and who checks their body for hours a day to ensure no new blemishes have appeared.

Illness Anxiety Disorder

Illness anxiety disorder involves preoccupation with having or acquiring a serious illness (criterion A). For example, an individual may fear contracting HIV or having recently contracted the virus. Illness anxiety disorder differs from somatic symptom disorder in that somatic symptoms are not present or are only minor (criterion B). If minor somatic symptoms are present (e.g., light pain, minor bruising), the individual's distress is clearly out of proportion to the actual threat and focuses more on the meaning of the symptoms (e.g., consequences of having diabetes) rather than on the somatic symptoms themselves. Individuals with illness anxiety disorder experience a great deal of distress rooted in their disease-related preoccupations and are easily alarmed about health-related matters (criterion C). To illustrate, an individual with illness anxiety disorder may be excessively distressed when learning that a colleague or family member has been diagnosed with cancer. Individuals with illness anxiety disorder participate in excessive behaviors aimed at reducing their anxiety (criterion D), often bodily checking (e.g., looking for lesions that could be signs of an infection), reassurance-seeking (e.g., repeatedly seeking medical testing), health-related research (e.g., reading about HIV on the Internet), and avoidance (e.g., avoiding hospitals as these could house harmful germs). These behaviors may placate concerns in the short term but, ultimately, serve to reinforce disease-related preoccupation (Taylor & Asmundson, 2004). A diagnosis of illness anxiety disorder is contingent on illness anxiety lasting at least 6 months (criterion E), although the focus of the anxiety may change during this time (e.g., from HIV to syphilis). Finally, the symptoms of illness anxiety disorder must not be better explained by another diagnosis (criterion F), such as somatic symptom disorder, panic disorder, or obsessive-compulsive disorder. There are two contrasting specifiers that can accompany illness anxiety disorder. The care-seeking type specifier is applied when individuals frequently seek medical care, whereas the care-avoidant type specifier is applied when individuals rarely use medical care.

Conversion Disorder (Functional Neurological Symptom Disorder)

Conversion disorder involves the manifestation of altered voluntary motor or sensory functioning (criterion A). Motor symptoms can include paralysis, paresthesia, tremors, convulsions, and abnormal movements or posture. Sensory symptoms can include blindness, altered or reduced hearing, unusual or inconsistent skin sensations, and altered speech patterns. The hallmark of conversion disorder is a lack of correspondence between signs and symptoms and medical understanding of the possible neurological condition (criterion B). For example, an individual may display symptoms very consistent with epileptic seizures, but lack electrical activity in the brain consistent with epilepsy. Such an inconsistency is needed for a diagnosis. A lack of neurological evidence for reported or observed symptoms is not sufficient (e.g., trembling without any apparent brain damage). Symptoms of conversion disorder must not be better explained by another mental health or medical disorder (criterion C) and the symptoms must cause clinically significant distress or impairment or warrant medical evaluation (criterion D).

People with conversion disorder are often unaware of psychological factors associated with their condition, and many report an inability to control their symptoms. Although not a criterion for diagnosis, lack of worry or concern about symptoms (i.e., la belle indifference) is mentioned in the DSM-5 list of associated features; however, the extant literature fails to support the use of la belle indifference as a means of discriminating between conversion disorder and symptoms of organic pathology (Stone, Smyth, Carson, Warlow, & Sharpe, 2006).

Observed signs and symptoms of conversion disorder often appear to represent patient beliefs about how neurological deficits should present, rather than how neurological diseases actually function (Hurwitz, 2004). Onset typically follows a period of distress, such as that stemming from trauma (McFarlane, Atchison, Rafalowicz, & Papay, 1994; Roelofs, Keijsers, Hoogduin, Naring, & Moene, 2002; Van der Kolk et al., 1996) or physical injury (Stone et al., 2009). There are several specifiers that can accompany conversion disorder, including with psychological stressor or without psychological stressor and acute episode (i.e., when symptoms present for less than 6 months) or persistent (i.e., when symptoms present for more than 6 months).

Psychological Factors Affecting Other Medical Conditions

A diagnosis of psychological factors affecting other medical conditions is given to individuals who suffer from a medical condition (criterion A) that is adversely affected by psychological or behavioral factors (criterion B). The effects on the medical condition can increase the odds of suffering, disability, or death. Psychological or behavioral factors can be deemed as detrimental if meeting one of the following conditions: (a) the psychological or behavioral factors preceded the development or worsening of the medical condition, or delayed recovery from the condition (e.g., repeatedly exacerbating an injury following discharge from hospital); (b) the factors interfere with treatment; (c) the factors are well established health risks; or (d) the factors influence medical pathology, thereby exacerbating symptoms or requiring medical attention. Psychological or behavioral factors can include distress, maladaptive interpersonal patterns, and poor treatment adherence. The psychological or behavioral factors must not be subsumed within another mental disorder (criterion C); thus, worsening of a medical condition due to panic disorder or due to substance abuse would not meet criteria for psychological factors affecting other medical conditions. The degree of influence of psychological factors on a medical condition can be specified as mild (increases medical risk), moderate (aggravates medical condition), severe (results in hospitalization or emergency attention), or extreme (life-threatening risk).

Factitious Disorder

Factitious disorder imposed on self is a condition wherein an individual acts as if they have physical or psychological signs of an illness by producing, feigning, or exaggerating symptoms (criterion A). The individual must present as ill or impaired (criterion B) and a diagnosis is contingent on identifying that the individual is actively misrepresenting their condition. Moreover, the deceptive behavior must occur without any obvious external rewards (criterion C), such as monetary compensation or reduced responsibilities. A diagnosis of factitious disorder can be assigned to individuals who have a medical condition, but, in such cases, the deceptive behavior is intended to make the person appear even more ill. The deceptive behavior cannot be better explained by another disorder, such as schizophrenia or delusional disorder (criterion D). Individuals with factitious disorder may produce or exaggerate symptoms by consuming drugs (e.g., insulin, hallucinogens), injecting themselves with noxious substances (e.g., bacteria), contaminating blood and urine samples, or reporting symptoms that have never occurred (e.g., seizures). A specifier of recurrent episodes is applied in cases where the individual has exhibited deceptive behavior more than once.

A separate diagnosis, referred to as factitious disorder imposed on another, can also be assigned. The criteria for this diagnosis are the same as factitious disorder, but a person other than the victim conducts the deceptive behavior. For example, a parent may tamper with the urine sample of his or her child to misrepresent the child's health status. In this case, the parent would be assigned the diagnosis, not the child.

Other Specified Somatic Symptom and Related Disorder and Unspecified Somatic Symptom and Related Disorder

Other specified somatic symptom and related disorder applies to individuals who present with distressing or impairing symptoms that are similar to one of the somatic symptom and related disorders but that do not fully satisfy the criteria for a diagnosis. The DSM-5 presents four specific disorders that can be used with the other specified disorder diagnosis. These include brief somatic symptom disorder, which can be assigned when an individual meets diagnostic criteria for somatic symptom disorder, but for less than 6 months; brief illness anxiety disorder, which can be assigned when symptoms of illness anxiety disorder last for less than 6 months; illness anxiety disorder without excessive health-related behaviors, which can be assigned when an individual meets all criteria for illness anxiety disorder except criterion D; and, pseudocyesis, which can be assigned in individuals with a false belief of being pregnant that is associated with objective and reported signs of pregnancy (e.g., morning sickness, breast tenderness). A diagnosis of unspecified somatic symptom and related disorder is applied when an individual presents with distressing or impairing symptoms that are similar to a somatic symptom and related disorder, but that do not meet the diagnostic criteria for any of the somatic symptom and related disorders.

Diagnostic Considerations (Including Dual Diagnosis)

To qualify for a DSM-IV-TR somatoform disorder diagnosis, somatic signs and symptoms were required to be medically unexplained (i.e., they could not be explained by organic pathology or physical deficit). Suggesting that diagnoses based on the absence of medically explained symptoms promoted stigma, the Somatic Symptom Workgroup noted that the reliability of establishing that somatic symptoms are not due to a general medical condition is low (Dimsdale et al., 2013; also see Sykes, 2006). As a consequence, DSM-5 somatic symptom disorder is defined on the basis of positive symptoms (i.e., distressing somatic symptoms that present along with “observable” cognitions, emotions, and behaviors in response to the somatic symptoms). It is, therefore, possible for people presenting with and without a diagnosable general medical condition to satisfy diagnostic criteria for the disorder. Medically unexplained symptoms only remain relevant to conversion disorder and other specified somatic symptom and related disorder (i.e., pseudocyesis), where it is possible to demonstrate inconsistency between presenting symptoms and medical pathology.

In arriving at a diagnosis of one of the somatic symptom and related disorders it is important to consider that there are multiple sources of distressing somatic sensation and changes. First, a number of mental health disorders are characterized by somatic symptoms (e.g., depression, panic disorder, post-traumatic stress disorder) and may either account for or accompany the somatic symptoms. In the former case, a somatic symptom and related disorder diagnosis would not be warranted, whereas in the latter case, a dual diagnosis would be warranted. Likewise, given that distressing somatic symptoms often occur in response to a general medical condition, such as cancer or multiple sclerosis, considerable care is warranted in establishing whether the response is psychopathological in nature. Some critics of the DSM-5 are concerned that diagnostic thresholds have been loosened to the point where clinicians will be challenged in distinguishing normal from psychopathological responses in those with distressing somatic symptoms stemming from a medical condition, resulting in overdiagnosis of somatic symptom disorders (Frances, 2013). There are also concerns about the validity of the new diagnostic criteria, particularly somatic symptom disorder (Rief & Martin, 2014). It is also important to recognize that many benign physical factors can give rise to somatic signs and symptoms. Consider, for example, physical deconditioning. People concerned by somatic sensations often avoid physical exertion, including aerobic and anaerobic exercise, for fear that it will have harmful consequences (Taylor & Asmundson, 2004). As a result, they become physically deconditioned. Physical deconditioning is associated with postural hypotension, muscle atrophy, and exertion-related breathlessness and fatigue, all of which can promote further inactivity and reinforce beliefs that one is ill.

According to the APA (2013), somatic symptom disorder encapsulates approximately 75% of individuals who previously met diagnostic criteria for hypochondriasis, and likely represents the most prevalent of the somatic symptom and related disorders. Emerging evidence on validity of the new classification of somatic symptom and related disorders suggests that only approximately half of individuals who meet DSM-IV-TR criteria for a somatoform disorder also meet criteria for a DSM-5 diagnosis of somatic symptom disorder (van Dessel, van der Wouden, Dekker, & van der Horst, 2016), although other research has found similar or slightly greater rates of diagnosis for somatic symptom disorder compared with DSM-IV-TR somatoform disorder (Voigt et al., 2012). Nonetheless, those who meet the DSM-5 criteria appear to have greater symptom severity and lower physical functioning, supporting the clinical utility of the diagnosis (van Dessel et al., 2016). There is criticism regarding splitting of new diagnoses; indeed, research on hypochondriasis suggests that about three-quarters of individuals diagnosed meet DSM-5 criteria for somatic symptom disorder and one-quarter for illness anxiety disorder, but that the two groups have few differences in terms of attitudes, behaviors, and physical symptoms (Bailer et al., 2016). Further research is required to determine whether the modifications made in the DSM-5 facilitate accuracy of diagnoses relative to that attainable with the DSM-IV-TR somatoform disorders. The importance of diagnosis cannot be overstated, as any diagnosis carries significant implications for individuals receiving the diagnosis and their related experiences (e.g., stigmatization, interpretation of symptoms, nature of treatment, response to treatment). As Kirmayer and Looper (2007) have noted, diagnosis is a form of intervention and, as such, is a crucial element in shaping treatment and outcome.

Epidemiology

Somatic symptom and related disorders are often associated with true or perceived organic pathology; consequently, this class of disorders is a challenge to diagnose and to study from an epidemiological standpoint due to difficulties in thoroughly assessing the mind and body. Given the substantial changes in diagnostic criteria between the DSM-III and DSM-5, providing precise epidemiological prevalence rates for somatic symptom and related disorders is extremely challenging. Indeed, the somatoform disorders were not included in the large-scale national comorbidity surveys based on DSM-III-R (Kessler, 1994) and DSM-IV-TR criteria (Kessler, Chiu, Demler, Merikangas, & Walters, 2005), nor were they examined in the World Health Organization World Mental Health Surveys initiative (Kessler & Üstün, 2008), which further limits inferences regarding the somatic symptom and related disorders. Moreover, epidemiological researchers have often paired somatoform disorders with other disorders (e.g., anxiety disorders; Bland, Orn, & Newman, 1988) or have excluded specific disorders from analyses due to low or high base rates or differences in classification methodologies (Leiknes, Finset, Moum, & Sandanger, 2008). Consequently, the prevalence of somatic symptom and related disorders as a class of disorders remains understudied and our knowledge at this time can only be extrapolated from earlier research on the somatoform disorders.

As noted earlier, the somatic symptom and related disorders are substantially different from the somatoform disorders described in DSM-IV-TR; however, some of the broader epidemiological findings likely still hold true. For example, presentation of somatic concerns that do not meet diagnostic criteria for a somatoform disorder or medical condition account for approximately half of all physician visits (Nimnuan, Hotopf, & Wessely, 2001), suggesting that subsyndromal somatic symptom presentations are highly prevalent and costly (Barsky et al., 2005; Kirmayer & Robbins, 1991). Somatic symptom and related disorders are likely more common in women (Wittchen & Jacobi, 2005), with perhaps the exception of somatic symptom disorder, which appears to have similar prevalence in both genders based on the rates of hypochondriasis (Asmundson, Taylor, Sevgur, & Cox, 2001; Bleichhardt & Hiller, 2007). People with a somatic symptom and related disorder are also very likely to frequently experience co-occurring mood disorders (Leiknes et al., 2008), anxiety disorders (Lowe et al., 2008), personality disorders (Bornstein & Gold, 2008; Sakai, Nestoriuc, Nolido, & Barsky, 2010), as well as other somatic symptom and related disorders (Leiknes et al., 2008).

Somatic symptom disorder has a prevalence of approximately 5–7% in the general population (APA, 2013), which is consistent with the 12-month prevalence rate of 4.5% for hypochondriasis (Faravelli et al., 1997). Research on hypochondriasis suggests that somatic symptom disorder is likely more common in primary care settings. Reported prevalence rates of hypochondriasis in primary care settings have varied considerably based on methodology. Studies using diagnostic interviews have reported a point prevalence of 3% (Escobar et al., 1998) and a 12-month prevalence of 0.8% (Gureje, Üstün, & Simon, 1997), whereas a study using cutoff scores from self-report measures followed by interviews suggests a 12-month prevalence of 8.5% (Noyes et al., 1993). The inclusion of the with predominant pain specifier to somatic symptom disorder, which subsumes a portion of the DSM-IV pain disorder diagnosis, may increase the prevalence of somatic symptom disorder beyond the prevalence of hypochondriasis.

The prevalence of illness anxiety disorder is relatively unknown, but can be estimated based on other phenomena. The 1- to 2-year prevalence of health anxiety and disease conviction (i.e., the belief that one has a disease) in community-based samples ranges from 1.3% to 10% (APA, 2013). A strong fear of contracting a disease, which is relatively similar to illness anxiety disorder, has a point prevalence of approximately 3– 4% (Agras, Sylvester, & Oliveau, 1969; Malis, Hartz, Doebbeling, & Noyes, 2002). Together these findings suggest that illness anxiety disorder is relatively common. The point and 12-month prevalence rates of conversion disorder in the general population are less than 0.1% (Akagi & House, 2001). Point prevalence rates in neurology and primary care settings have been reported as 1% (Smith, Clarke, Handrinos, Dunsis, & McKenzie, 2000) and 0.2% (de Waal, Arnold, Eekhof, & van Hemert, 2004), respectively. Despite low prevalence of conversion disorder, medically unexplained neurological symptoms are present in approximately 11– 35% of neurology patients (Carson et al., 2000; Snijders, de Leeuw, Klumpers, Kappelle, & van Gijn, 2004), suggesting that subsyndromal conversion may be more common than almost all neurological diseases. The prevalence of other somatic symptom and related disorders are unknown, partially because they are new diagnoses (e.g., psychological factors affecting other medical conditions) and are very difficult to study (e.g., factitious disorder, unspecified somatic symptom and related disorder).

Psychological and Biological Assessment

Individuals with somatic symptom and related disorders will typically present in primary care and other medical (nonpsychiatric) clinics rather than in mental health settings; indeed, they may often refuse a mental health referral because of a belief that their condition is purely organic. Cooperation between medical and mental health professionals aids the referral process and, due to the complexity of the factors involved (e.g., possibility of co-occurring organic pathology), is typically necessary in making an accurate diagnosis. Throughout the course of assessing a person with a possible somatic symptom and related disorder, the mental health professional must seek to establish and maintain rapport and should clearly relay an understanding that, although a disease process may or may not be present, the symptoms are real and not feigned or “in the head” (Taylor & Asmundson, 2004). The general goals of assessment for the somatic symptom and related disorders are to rule out organic pathology-based, substance-based, or other psychopathology-based explanations of presenting signs and symptoms, to determine the type and severity of signs and symptoms, and to facilitate appropriate treatment planning.

Ruling out organic pathology is no longer requisite to diagnosis of somatic symptom and related disorders, as it was in the DSM-IV-TR somatoform disorders. This aspect of the diagnostic process was considered problematic for two primary reasons. First, it relied heavily on the exclusion of general medical conditions, and 100% certainty was rarely, if ever, possible (Taylor & Asmundson, 2004; Woolfolk & Allen, 2007). Second, diagnosis is not usually based on the absence of something but, rather, according to the presence of positive features of a condition (Dimsdale et al., 2013). Gathering a detailed history of somatic complaints, past and current medical conditions, and medical professionals consulted is a crucial part of a comprehensive diagnostic process and may provide insight regarding the nature of the presenting condition. A consult with the family physician may be necessary to determine the need for further medical assessments; however, caution is warranted, because further assessments may reinforce maladaptive coping (e.g., reassurance-seeking) while also increasing the costs and potential risks associated with medical care.

Structured clinical interviews have proven to be the gold standard in the diagnosis of mental disorders, and will likely remain so for the somatic symptom and related disorders. Broad structured interviews that include sections on numerous mental disorders are the most commonly utilized. The Structured Clinical Interview for the DSM-IV (First, Spitzer, Gibbon, & Williams, 1996) and the Composite International Diagnostic Interview (CIDI; World Health Organization, 1990) based on the International Statistical Classification of Diseases, 10th edition, criteria (ICD-10; World Health Organization, 2007) were both used widely and demonstrated efficacy and reliability in diagnosing somatoform disorders. Other useful structured interviews for diagnosing somatoform disorders included the Somatoform Disorders Schedule (World Health Organization, 1994), the Schedules for Clinical Assessment in Neuropsychiatry (Wing et al., 1990), and the Diagnostic Interview Schedule (Robins, Helzer, Croughan, & Ratcliff, 1981). The majority of these structured interviews have not been updated for DSM-5 somatic symptom and related disorders, with the exception of the Structured Clinical Interview for DSM-5 (First, Williams, Karg, & Spitzer, 2015), which queries somatic symptom disorder and illness anxiety disorder. Additionally, the Health Preoccupation Diagnostic Interview (Axelsson, Andersson, Ljótsson, Wallhed Finn, & Hedman, 2016) is a newly developed instrument for the diagnosis of DSM-5 somatic symptom disorder and illness anxiety disorder that has preliminary evidence for its reliability.

Structured clinical interviews can be supplemented with diarized monitoring of catastrophic thinking and maladaptive coping behaviors as well as information gleaned from standardized self-report measures. Self-report measures are efficient and effective screening tools that can provide invaluable information for case conceptualization and regular monitoring of treatment progress. The Screening for Somatoform Symptoms (Rief, Hiller, & Heuser, 1997), the Symptom Checklist-90, Revised (Derogatis, 1975), or the Patient Health Questionnaire-15 (Kroenke, Spitzer, & Williams, 2002) have been used to assess a broad range of somatic symptoms. More specific information can be derived from a wide array of self-report measures that have been developed to assess the severity of specific somatic symptoms. It is beyond the scope of this chapter to provide a comprehensive list of these measures; examples include the Health Attitude Survey (Noyes, Langbehn, Happel, Sieren, & Muller, 1999), for use in assessing attitudes and perceptions associated with multiple somatic symptoms; the Health Anxiety Questionnaire (Lucock & Morley, 1996), for use in assessing reassurance-seeking behavior and the extent to which symptoms interfere with a person's life; the Whiteley Index (Pilowsky, 1967), for use in assessing cognitions associated with health anxiety; and the Short Health Anxiety Inventory (Salkovskis, Rimes, Warwick, & Clark, 2002), to assess health anxiety in both medical and nonmedical populations. Instruments developed in relation to the DSM-5 classification include the Somatic Symptom Scale–8 (Gierk et al., 2014; an abbreviated version of the Patient Health Questionnaire-15 developed for DSM-5 somatic symptom disorder field trials), as well as the Somatic Symptom Disorder-B Criteria Scale (Toussaint et al., 2015, 2017). Medical service utilization and visual analogue scales pertaining to distressing thoughts and maladaptive coping behaviors can also be used to assess emotional and functional impact and to monitor treatment progress. Finally, measures of mood and anxiety can be useful in case conceptualization and monitoring and might include the Beck Depression Inventory-II (Beck, Steer, & Brown, 1996), the Beck Anxiety Inventory (Beck & Steer, 1993), and the Anxiety Sensitivity Index-3 (Taylor et al., 2007).

Etiological Considerations

Behavioral Genetics and Molecular Genetics

Heritability of somatoform disorders has been suggested by findings from behavioral (e.g., Kendler et al., 2011; Torgersen, 1986) and molecular (e.g., Hennings, Zill, & Rief, 2009) genetics studies. Somatic symptom concordance rates between monozygotic twins are higher than between dizygotic twins, even when controlling for co-occurring psychiatric symptoms (Lembo, Zaman, Krueger, Tomenson, & Creed, 2009). Although mood and somatoform disorders share common genetic factors (e.g., deregulation of serotonergic pathways), there are numerous genetic features unique to somatoform disorders (e.g., immunological deregulation, hypothalamic–pituitary–adrenal [HPA] axis responses; Rief, Hennings, Riemer, & Euteneuer, 2010). The role of specific genetic markers in the development of somatic symptoms remains unclear; however, research in this area is ongoing, and genetic factors are now being considered within the context of psychological models of various somatoform disorders (e.g., Taylor, Jang, Stein, & Asmundson, 2008; Veale, 2004). Whether these findings generalize to the somatic symptom and related disorders remains to be determined.

Neuroanatomy and Neurobiology

Neurological research on the DSM-5 somatic symptom and related disorders remains in its infancy; but, research using DSM-IV-TR criteria has demonstrated neurological correlates for conversion disorder (e.g., Vuilleumier, 2005), hypochondriasis (e.g., Atmaca, Sec, Yildirim, Kayali, & Korkmaz, 2010), and other related disorders (e.g., somatization disorder; Hakala, Vahlberg, Niemi, & Karlsson, 2006; pain disorder and fibromyalgia, Wood, Glabus, Simpson, & Patterson, 2009). The HPA axis has been a focus of research in this area. A recent longitudinal study reported preliminary evidence that cortisol deregulation in the HPA axis may predate the development of somatic symptoms in some people (Tak & Rosmalen, 2010). The HPA axis controls glandular and hormonal responses to stress and, when stressors (e.g., chronic pain, anxiety) have a chronic course, may lead to hypocortisolism (i.e., adrenal insufficiency), which induces greater stress and enhances experiences of pain and fatigue (Fries, Hesse, Hellhammer, & Hellhammer, 2005). Increases in these experiences typically exacerbate somatic symptoms or lead to behaviors that exacerbate or maintain them (Taylor & Asmundson, 2004). The second somatosensory area (SII) of the cerebral cortex, which is involved in the analysis and evaluation of complex patterns of somesthetic input (e.g., perception of pain, sensations from visceral structures, gastric sensations), has also been implicated as a source of the somatic perturbation associated with the somatoform disorders (Miller, 1984); however, despite its appeal as a neural structure underlying this class of disorders, people presenting with concerns about somatic symptoms do not typically show abnormalities in sensory acuity.

Learning, Modeling, and Life Events

Adverse life events (e.g., childhood physical and sexual abuse, neglect) have been associated with increased physician visits during adulthood (Fiddler, Jackson, Kapur, Wells, & Creed, 2004), health anxiety (Reiser, McMillan, Wright, & Asmundson, 2013), hypochondriasis (Barsky, Wool, Barnett, & Cleary, 1994), and unexplained somatic symptoms (Tak, Kingma, van Ockenburg, Ormel, & Rosmalen, 2015). Unfavorable socioeconomic conditions during development may also be associated with unexplained somatic symptoms in adulthood, likely because socioeconomic status may engender a series of social and material difficulties (Jonsson, San Sebastian, Strömsten, Hammarström, & Gustafsson, 2016); however, it is noteworthy that increased prevalence of abuse and other stressful life events are characteristic of people with a variety of psychiatric conditions (e.g., panic disorder; Taylor, 2000), not just those presenting with concerns regarding somatic symptoms. Early childhood experiences of illness and perceptions of significant illness in others are associated with the experience of medically unexplained symptoms in adulthood (Hotopf, Wilson-Jones, Mayou, Wadsworth, & Wessely, 2000). Likewise, parents who fear disease, who are preoccupied with their bodies, and who overreact to minor ailments experienced by their children are more likely to have children with the same tendencies, both during childhood and adulthood (Craig, Boardman, Mills, Daly-Jones, & Drake, 1993; Hotopf, Mayou, Wadsworth, & Wessely, 1999; Marshall, Jones, Ramchandani, Stein, & Bass, 2007). That being said, a recent twin study suggests that environmental factors not shared by twins (e.g., an ailment in one of the twins), rather than shared environmental factors (e.g., parental style), seem most important in the development of DSM-IV-TR-defined hypochondriasis (Taylor & Asmundson, 2012).

Cognitive Influences

Greater focus on somatic sensations is associated with greater experiences of those sensations (Brown, 2004; Ursin, 2005). When attention is directed to the body, the intensity of perceived sensations increases (Mechanic, 1983; Pennebaker, 1980). People with somatoform disorders have been shown to spend a considerable amount of time focusing on their bodies, thereby increasing their chances of noticing somatic sensations and changes. They also tend to believe that somatic sensations and changes are indicative of disease or are otherwise harmful in some way (Barsky, 1992; Taylor & Asmundson, 2004; Vervoort, Goubert, Eccleston, Bijttebier, & Crombez, 2006). These beliefs increase the attention directed to somatic sensations and changes and, in turn, increase associated distress. It is likely that similar cognitive influences will be identified in the various somatic symptom and related disorders diagnoses.

Sex and Racial-Ethnic Considerations

As noted in the “Epidemiology” section, the somatoform disorders were more prevalent in women than in men, perhaps with the exception of hypochondriasis. There are several possible explanations for this difference. Because women are more likely to seek medical services (Corney, 1990; Kessler et al., 2008), they may be more prone to diagnostic biases wherein physicians consider somatic symptoms presented by a woman as more likely to be psychological than organic in nature (e.g., Martin, Gordon, & Lounsbury, 1998). Women also tend to experience higher rates of psychopathology (Kessler et al., 2008). Shared etiological or maintenance factors between mental disorders may make it more likely that women are at a higher risk of developing a somatic symptom and related disorder. There is evidence that women tend to focus more on their bodies (Beebe, 1995) and are more fearful of some of their bodily sensations (Stewart, Taylor, & Baker, 1997), further increasing their risk for developing somatic symptom and related disorders. Other putative sex differences have been proposed (e.g., differential experiences of abuse; HPA axis dysregulation) but warrant further empirical scrutiny in the context of their role in somatic symptom and related disorders etiology.

Somatic sensations and changes are common in all cultural groups; however, presentation varies widely depending on sociocultural norms (Kirmayer & Young, 1998). Cultural factors, such as socially transmitted values, beliefs, and expectations, can influence how a person interprets somatic sensations and changes, and whether treatment-seeking is initiated. Some cultures appear to be more distressed by gastrointestinal sensations (e.g., excessive concerns about constipation in the UK), whereas others are more distressed by cardiopulmonary (e.g., excessive concerns about low blood pressure in Germany) and immunologically based (e.g., excessive concerns about viruses and their effects in the USA and Canada) symptoms (Escobar, Allen, Hoyos Nervi, & Gara, 2001). Whether one seeks care for somatic concerns also appears to vary as a function of culture, with those of Chinese, African American, Puerto Rican, and other Latin American descent presenting with more medically unexplained somatic symptoms than those from other groups (Escobar et al., 2001). Whether concern over somatic sensations and changes are excessive needs to be judged in the context of the individual's cultural background.

Course and Prognosis (Including Issues of Treatment)

As a diagnostic category, somatic symptom and related disorders share somatic features and concerns as a prominent aspect of clinical presentation. That said, each disorder does not necessarily share a similar course and prognosis. Like the somatoform disorders, course and prognosis may vary considerably, because the disorders are heterogeneous in presentation and involve substantial comorbidity with mood and anxiety disorders, personality disorders, and, in some cases, general medical conditions. Certain prognostic indicators have been shown to be common across somatoform disorders; for example, comorbidity with other psychiatric disorders contributes to a more chronic and persistent course (e.g., Rief, Hiller, Geissner, & Fichter, 1995). More somatic symptoms, sensitization to bodily sensations and pain, as well as presence of a medical condition all contribute to greater severity and chronic course (APA, 2013). The presence of fewer somatic symptoms, few or no comorbid conditions, identifiable stressors at the time of onset, high intellectual functioning, as well as sound social support networks are typically associated with good prognosis. Also indicative of good prognosis is the development of a strong therapeutic alliance between the patient and care provider, wherein the patient believes that the care provider views the patient's presenting signs and symptoms as legitimate, albeit possibly not due to an organic pathology or physical defect (Taylor & Asmundson, 2004).

Little research on psychological interventions for somatic symptom disorders currently exists. A recent randomized controlled trial found large improvements in individuals with somatic symptom disorder or illness anxiety disorder engaged in Internet cognitive-behavioral therapy (CBT), unguided Internet CBT, and unguided bibliotherapy compared with a waitlist (Hedman, Axelsson, Andersson, Lekander. & Ljotsson, 2016). CBT has also demonstrated efficacy across the DSM-IV-TR somatoform disorders. The treatment is superior to standard medical care in reducing health-related anxiety (Barsky & Ahern, 2004) and improving somatic complaints/somatization (Allen, Woolfolk, Escobar, Gara, & Hamer, 2006; Speckens, van Hemert, Bolk, Rooijmans, & Hengeveld, 1996). These findings are echoed by a recent meta-analysis of CBT trials for hypochondriasis and health anxiety (Olatunji, Kauffman, Meltzer, Davis, Smits, & Powers, 2014) as well as more recent health anxiety treatment trials (Weck, Neng, Schwind, & Hofling, 2015). Psychiatric consultation letters to primary-care physicians describing somatization and providing recommendations for primary care have also been shown to significantly improve physical functioning and reduce the cost of medical care (Rost, Kashner, & Smith, 1994). Finally, a stepped care approach, including distinguishing between acutely and nonacutely serious complaints, assessing and treating psychiatric comorbidities, and developing a multimodal approach to managing symptoms, could be an effective way forward in addressing somatic symptom disorders in primary care (Hubley, Uebelacker, & Eaton, 2014; Korenke, 2003).

Case Study

Case Identification

The basic features of this case are undisguised; however, in line with Clifft's (1986) guidelines, identifying information has been altered or omitted to protect confidentiality and privacy.

Jacob is a 37-year-old White male who has been married for 10 years and has a 5-year-old daughter and a 6-month-old son. He currently resides with his wife and children in an upper-middle-class suburban neighborhood. His family is financially secure, and he is not involved in any legal proceedings. Jacob is employed full time as an electrical engineer for a large company, a job he has held for the past 6 years. He enjoys a variety of sports, walking the family dog, and spending time with his family. Until recently, he was active as a competitive triathlete. His job requires that he travel periodically, with absences from home and his family for up to 1 month at a time. He reports that job demands increase in the months prior to extended travel and that his next lengthy trip is fast approaching in 10 weeks.

Presenting Complaints

Jacob was referred by his family physician for assessment and, if appropriate, treatment of increasing anxiety over his physical well-being which was negatively impacting on his work (e.g., spending excessive amounts of time searching medical information on the Internet instead of working) as well as leisure and family functioning (e.g., withdrawing from physical activity and shared leisure activities). These concerns started 9 months ago, when his father died of heart complications associated with amyloidosis, a disease wherein amyloid proteins build up in specific organs and, over time, disrupt organ function and eventually lead to failure of the affected organs. There is a rare form—hereditary amyloidosis—that is most frequently passed from father to son and for which there are no preventive measures other than not having children. There is no cure for amyloidosis, and the effects do not become apparent until later in life (i.e., over the age of 50 years). Beginning shortly after his father's death, Jacob became increasingly aware of and concerned by somatic sensations in his body—heart palpitations and racing, upper body aches and pain, dizziness, and blurred vision—all of which were similar to those initially experienced by his father. He feared that he may also have amyloidosis and might die from it. His fears were exacerbated upon the birth of his son, with specific concerns that he had passed on the condition and that his son would eventually succumb as well.

History

Jacob had no prior history of mental health problems or treatment and, aside from chickenpox and tonsillitis as a child, had been physically healthy throughout his life. The report from his physician indicated that, despite numerous visits regarding various somatic complaints over recent months, there was no evidence of an organic basis for Jacob's concerns. The physician report also indicated that Jacob was physically healthy and that he and his son had a pending appointment for genetic testing to rule out the genetic profile for hereditary amyloidosis. Jacob reported having a loving and supportive relationship with his wife, although she was becoming increasingly concerned by his condition and, at times, annoyed at his growing reluctance to actively play with their children. Until recently, he was exercising five or six times per week and had competed in numerous triathlons; however, because of growing concerns about his health, he had significantly cut down his frequency of training and was not competing in order to “avoid physical exertion” for fear that his heart would “explode.” In place of training, he was spending hours checking the Internet for medical information.

Assessment (Related To DSM-5 Criteria)

Jacob was assessed using the Structured Clinical Interview for the DSM-5 and a battery of self-report questionnaires, including (a) the Beck Depression Inventory-II, a measure of depression over the past 2 weeks (Beck et al., 1996), (b) the Beck Anxiety Inventory, a measure of general anxiety over the past week (Beck & Steer, 1993), (c) the Anxiety Sensitivity Index-3 (Taylor et al., 2007), a measure of the fear of arousal-related bodily sensations, and (d) the Whiteley Index (Pilowsky, 1967), a measure of the core features of health anxiety, including disease fear, disease conviction, and bodily preoccupation. The structured interview and self-report measures provided detailed data regarding general features of Jacob's distress, as well as specific features of his health-related concerns.

Jacob met the DSM-5 diagnostic criteria for somatic symptom disorder. He presented with several specific concerns, including daily worry that somatic changes and sensations (e.g., heart palpitations and racing, upper body aches and pain, dizziness, blurred vision) were signs of physical disease as well as increasing inability to focus on work-related tasks and to be involved in family activities (somatic symptom disorder criterion A). He also presented with considerable worry and anxiety about his personal health and the future-oriented health and well-being of his 6-month-old son, and reported spending hours on the Internet checking medical information (somatic symptom disorder criterion B). His concerns had, as noted previously, begun around the time of his father's death 9 months prior and had persisted since then (somatic symptom disorder criterion C).

Given that the effects of amyloidosis are typically not evident until later in life, and that Jacob was in his mid-30s, it was deemed unlikely that amyloid deposits were responsible for the bodily sensations he was experiencing; however, since Jacob (and his son) had not yet completed genetic testing and did not know whether they had the genetic profile for hereditary amyloidosis at the time of assessment, we remained cautious in our opinion as to whether his thoughts about the seriousness of symptoms were disproportionate. At the time of assessment, Jacob's score on the Whiteley Index was moderate overall (score = 8; possible range 0–14), characterized by significant disease fear (score = 3; possible range 0–4) and bodily preoccupation (score = 3; possible range 0–3) but little disease conviction (score = 0; possible range 0–3), the latter of which is indicative of good prognosis with treatment (Taylor & Asmundson, 2004). The moderately high levels of health anxiety combined with excessive checking behavior, in our opinion, were sufficient to warrant a moderate severity specifier.

Jacob did not meet diagnostic criteria for other diagnosis. Scores on the Beck Depression Inventory (score = 13; possible range 0–63) and Beck Anxiety Inventory (score = 26; possible range 0–63) suggested a mildly depressed mood and moderate general anxiety, respectively. The absence of comorbid diagnoses, along with depression and general anxiety in the mild to moderate range, are also indicative of good prognosis with treatment (Taylor & Asmundson, 2004). His score on the Anxiety Sensitivity Index-3 (score = 33; possible range 0–72) indicated strong beliefs that arousal-related bodily sensations have harmful consequences, which, when considered in the context of his significant disease fear and bodily preoccupation, suggest that attention-focusing exercises (e.g., Furer, Walker, & Stein, 2007; Wells, 1997) and interoceptive exposure (Taylor & Asmundson, 2004) may prove to be particularly beneficial additions to treatment.

Summary

Conditions characterized by significant concern over somatic signs and symptoms, often presenting as medically unexplainable, are associated with significant emotional distress, cognitions characterized by catastrophic thinking, maladaptive coping behaviors typically manifest as excessive checking and reassurance-seeking, limitations in social and occupational functioning, and excessive use of health care resources. These conditions are represented by the disorders subsumed under the DSM-5 somatic symptom and related disorders. While it is generally agreed that changes to the former DSM conceptualizations of the somatoform disorders were warranted, it remains to be determined whether the changes set forth in the DSM-5 somatic symptom and related disorders will promote more accurate diagnosis of people concerned and functionally disabled by somatic sensations and changes and, if so, whether this will direct appropriate treatment resources to optimize outcomes. It also remains unclear if, or how, the changes to classification will facilitate efforts to identify underlying mechanisms. The burden on the health care system and the personal distress associated with somatic symptoms highlight the need for appropriate reconceptualization of disorders characterized by somatic symptom presentation; however, some investigators have suggested that there was insufficient empirical evidence to warrant change, that important evidence may have been overlooked, and that the changes in the DSM-5 may have been premature (Taylor, 2009; Sirri & Fava, 2013; Starcevic, 2013) or lacking in precision and clarity (Rief & Martin, 2014), and that the new changes will increase, rather than decrease, diagnostic misclassification (Frances, 2013). Answers to these questions await the accumulation of empirical evidence based on the DSM-5 diagnostic criteria. Efforts such as the EURONET-SOMA initiative (Weigel et al., 2017), which is bringing leading European experts in the field together to work on research agendas, diagnostic issues, and treatment, hold promise in providing answers to the many questions that remain.

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