Description

• Somatic symptom disorders (SSD) are a pattern of one or more somatic symptoms recurring or persisting for >6 months that are distressing or result in significant disruption of daily life.
• Designation of a symptom as somatic means that it appears to be physical problem or complaint yet is medically unexplained.
• Conceptualization and diagnostic criteria for somatic symptom presentations were significantly modified with the advent of Diagnostic and Statistical Manual, 5th edition (DSM-5). SSD is similar in many aspects to the former somatization disorder, which required presentation with multiple physical complaints; no longer based on symptoms counts; current diagnosis is based on the way the patient presents and perceives his or her symptoms.
• SSD now includes most presentations that would formerly be considered hypochondriasis. Hypochondriasis has been replaced by illness anxiety disorder, which is diagnosed when the patient presents with significant preoccupation with having a serious illness in the absence of illness-related somatic complaints.
• Somatization increases disability independent of comorbidity, and individuals with SSD have health-related functioning that is 2 standard deviations below the mean.
• Symptoms may be specific (e.g., localized pain) or relatively nonspecific (e.g., fatigue).
• Symptoms sometimes may represent normal bodily sensations or discomfort that does not signify serious disease.
• Suffering is authentic. Symptoms are not intentionally produced or feigned.
• SSDs are sometimes referred to as “functional disorders” to denote their nonphysical basis and with the assumption that the illness behavior is a function of the environment.

Epidemiology

Incidence

• Usually, first symptoms appear in adolescence.
• Predominant sex: female > male (10:1)
• Type and frequency of somatic complaints may differ among cultures, so symptom reviews should be adjusted based on culture; more frequent in cultures without Western/empirical explanatory models

Prevalence

• Expected 2% among women and <0.2% among men
• Somatization is seen in up to 29% of patients presenting to primary care offices.
• Somatic concerns may increase, but other features of the presentation decrease such that prevalence declines after age 65 years.

Etiology and Pathophysiology

Patients with SSD demonstrate different patterns of heart rate variability. Although this cannot be used to clinically differentiate, it does point to the differences in psychophysiology of SSD. Also, not to be used clinically, patients with SSD display differences in brain functional connectivity, with the possibility that deficits in attention distort perception of external stimuli, affecting regulation of externally responsive body functioning (1)[C]. Reduced density in the form of decreased cell counts and radiologic signaling have also been detected in brain areas related to somatic sensation and emotional experience.

Genetics
Consanguinity studies and single nucleotide polymorphism genotyping indicate that both genetic and environmental factors contribute to the risk of SSD.

Risk Factors

• Child abuse, particularly sexual abuse, has been shown to be a risk factor for somatization.
• Symptoms begin or worsen after losses (e.g., job, close relative, or friend).
• Greater intensity of symptoms often occurs with stress.

Commonly Associated Conditions

Comorbid with other psychiatric conditions is yet to be determined but is likely to be 20–50% with anxiety, depression, or personality disorders.