Somatic symptom disorder (SSD) is a recently defined diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V). It is the manifestation of one or more physical symptoms accompanied by excessive thoughts, emotion, and/or behavior related to the symptom, which causes significant distress and/or dysfunction. These symptoms may or may not be explained by a medical condition. The two major changes to the DSM-IV criteria included eliminating the requirement that somatic symptoms be organically unexplained and adding the requirement that certain psychobehavioral features have to be present to justify the diagnosis. The new criteria also eliminated somatization disorder, undifferentiated somatoform disorder, hypochondriasis, and pain disorder from the previous definitions. These revisions were intended to increase the relevance of SSD and its use in the primary care setting.
Somatic symptom disorder (SSD) arises from a heightened awareness of various bodily sensations, which are combined with an inclination to interpret these sensations as indicative of medical illness. While the etiology of SSD is unclear, studies have investigated risk factors including childhood neglect, sexual abuse, chaotic lifestyle, and history of alcohol and substance abuse. Furthermore, severe somatization has been associated with axis II personality disorders, particularly avoidant, paranoid, self-defeating, and obsessive-compulsive disorder. Psychosocial stressors, including unemployment and impaired occupational functioning, have also been implicated.
The prevalence of somatic symptom disorder (SSD) is estimated to be 5% to 7% of the general population, with higher female representation (female-to-male ratio 10:1), and can occur in childhood, adolescence, or adulthood. The prevalence increases to approximately 17% of the primary care patient population. The prevalence is likely higher in certain patient populations with functional disorders including fibromyalgia, irritable bowel syndrome, and chronic fatigue syndrome.
The pathophysiology of somatic symptom disorder (SSD) is unknown. Autonomic arousal from endogenous noradrenergic compounds may cause tachycardia, gastric hypermotility, heightened arousal, muscle tension, and pain associated with muscular hyperactivity in patients with SSD. There may also be a genetic component. A study of monozygotic and dizygotic twins revealed that the contribution of genetic factors to somatic symptoms was 7% to 21%, while the remaining was attributable to environmental factors. Several single nucleotide polymorphisms were associated with somatic symptoms in another study.
Three requirements fulfill the diagnostic criteria for somatic syndrome disorders (SSDs) according to the American Psychiatric Association's 2013 DSM-5:
The presence of SSD may be suggested by a vague and often inconsistent history of present illness, symptoms that are rarely alleviated with medical interventions, patient attribution of normal sensations as medical illness, avoidance of physical activity, high sensitivity to medication adverse effects, and medical care from multiple providers for the same complaints.
In addition to a thorough history, a full review of systems (not only at the location of the symptom) and a comprehensive physical exam is required to evaluate for physical causes of somatic complaints. Given frequent comorbid psychiatric disease, a mental status examination should be performed, noting appearance, mood, affect, attention, memory, concentration, orientation, the presence of hallucinations or delusions, and suicidal or homicidal ideation. Ultimately, the physical examination may provide a baseline for monitoring over time, assure patients that their complaints are acknowledged, and help validate the primary care provider’s concern that the patient does not have a physical medical illness. If a disease is present, the exam may provide information on severity.
Limited laboratory testing is recommended as it is common for patients with somatic syndrome disorder (SSD) to have had a thorough prior workup. Excessive testing introduces the risk of false-positive results which can subsequently lead to additional interventional procedures, its associated risks, and increased costs. While some clinicians order tests to provide reassurance to the patient, studies reveal that such diagnostic testing does not alleviate SSD symptoms. A meta-analysis by Rolfe and colleagues compared diagnostic testing versus a non-testing control condition, demonstrated that resolution of somatic symptoms and reduction of illness concern and anxiety was comparable between both groups. There was only a modest decrease in subsequent visits in the group that received diagnostic testing.
If it is necessary to rule out somatization due to medical conditions, specific studies may be ordered, including but not limited to thyroid function tests, urine drug screen, limited blood studies (i.e., alcohol level), and limited radiological testing.
The primary objective is to help the patient cope with physical symptoms, including health anxiety and maladaptive behaviors, as opposed to eliminating the symptoms. Caution must be exercised when conveying to patients that their physical symptoms are exacerbated by anxiety or excessive emotional problems as patients may be resistant to this suggestion. The primary care provider should schedule regular visits to reinforce that symptoms are not suggestive of a life-threatening or disabling medical condition. Diagnostic procedures and invasive surgical treatment are not recommended. Sedative medications, including benzodiazepines and narcotic analgesics, are avoided. Early psychiatric treatment is recommended. Studies have shown that cognitive-behavioral therapy is associated with significant improvement in patient-reported functioning and somatic symptoms, a decrease in health care costs, and a reduction in depressive symptoms. Pharmacologic approaches should be limited, but antidepressants can be initiated to treat psychiatric comorbidities (anxiety, depressive symptoms, obsessive-compulsive disorder). Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) have shown efficacy with an improvement of SSD compared to placebo. However, medications should be initiated at the lowest dose and increased slowly to achieve a therapeutic effect as patients with SSD may have a low threshold for perceiving adverse effects, introducing another source of concern.
The diffuse, non-specific symptoms in somatic syndrome disorder (SSD) may confound and mimic presentations of other medical illnesses, making diagnosis and treatment difficult. Excessive and disproportionate emotional and behavioral responses may be present in adjustment disorder, body dysmorphic disorder, obsessive-compulsive disorder, and illness anxiety disorder. Other functional disorders of unclear etiology, including fibromyalgia and irritable bowel syndrome, do not typically manifest with excessive thoughts, emotions, or maladaptive behavior.
Longitudinal studies show considerable chronicity, with up to 90% of somatic syndrome disorder (SSD) cases lasting longer than 5 years. Systematic reviews and meta-analyses have revealed that therapeutic interventions only yield small-to-moderate effect sizes. Chronic limitation of general function, significant psychological disability, and decreased quality of life are frequently observed.
Alcohol and drug abuse are frequently observed, and sometimes utilized to alleviate symptoms, increasing the risk of dependence on controlled substances. If the provider decides to pursue invasive diagnostic procedures or surgical interventions, iatrogenic complications may arise.
Evaluation by a psychiatrist is beneficial to diagnose accompanying mood disorders.
The provider should acknowledge the patient’s symptoms and suffering and offer frequent follow-up evaluations. Patients should primarily discuss any somatic symptoms with their primary care provider, who will assess the need for subspecialty evaluation. Prompt treatment of psychiatric comorbidities and addressing life stressors may improve somatic symptoms. Education of family members is often necessary. Family members should spend time with patients, particularly when symptoms are absent, to avoid reinforcing the idea that symptoms bring special attention from others.
As suggested by Frances et al., the diagnostic criteria of somatic syndrome disorders (SSDs) are liberal and easy to meet. If a patient has a medical illness that causes excessive worry, he or she may be diagnosed with SSD based on DSM-V criteria. Furthermore, these criteria are subjective, unreliable, and may predispose the provider to pursue an incomplete diagnostic workup, potentially missing underlying medical or psychiatric illnesses. The previous concern with the DSM-IV criteria was that it was too restrictive and stringent; for instance, to meet criteria for somatoform disorder per DSM-IV one would have to report four distinct pain symptoms, two gastrointestinal symptoms, one sexual or reproductive symptom other than pain, and one pseudoneurological complaint. However, in the effort to define criteria that are more utilized in the clinical setting, the DSM-V work group may have set definitions with high sensitivity but low specificity, capturing 7% of healthy people. Frances et al. proposed changes to reduce false-positive overdiagnosis. Firstly, for patients with a medical illness, the reaction would have to be specified as “maladaptive,” “extreme,” “intrusive,” “impairing,” and “grossly in excess” compared to the expected reaction. These specific words may reduce the misdiagnosis in patients who have adaptive vigilance of their health concerns. In those with no diagnosed medical illness, there would have to be adequate and repeated medical workups at suitable intervals to uncover medical conditions that may present with time. The final suggested criterion is to rule out psychiatric disorders, particularly panic, generalized anxiety, and depression as these disorders may manifest with physical symptoms.
Some providers find patients with SSD difficult to manage and often describe them in derogatory terms; the the misconceived bias is that physical disorders are considered genuine, while those with SSD are inappropriately accused of manufacturing their symptoms. As an increasing primary care population with medically unexplained symptoms receives a diagnosis of SSD, there is a need to educate and train physicians about SSD, its significance, and how to best manage these patients.