Somatic symptom disorders

Definition/diagnostic criteria Somatic symptom disorders, previously known as somatoform disorders, are characterised by physical complaints that cannot be fully explained by a medical condition. These disorders are significant due to their personal morbidity and cost to the health service.

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) – like its predecessor DSM-IV – defines this disorder as involving distress and disruption in daily life, not necessarily requiring the symptoms to be unexplained​​​​.

Epidemiology Epidemiological studies reveal the extensive prevalence of somatic symptom disorders. For example, a World Health Organization study found that 22% of primary care patients reported persistent pain, with a notable co-occurrence of anxiety or depressive disorders and significant activity limitations​​.

Diagnosis
Clinical features: Patients often present with chronic physical complaints, such as pain or discomfort, without an obvious physical cause. These symptoms are commonly referred to as medically unexplained symptoms (MUS) and encompass a wide range of conditions, including irritable bowel syndrome and fibromyalgia​​​​.

Investigations: Typical investigations may include blood tests and scans, but often these tests do not reveal a clear physical cause for the symptoms. The lack of clear abnormalities in these investigations is a hallmark of somatic symptom disorders​​.

Treatment Treatment focuses on improving function in daily life. This is often through a combination of CBT, antidepressant or anti-anxiolytic medication as appropriate and treatment of physical symptoms.

Prognosis The prognosis of somatic symptom disorders can be variable. Patients with longer durations of untreated symptoms generally have a poorer prognosis. There’s also a notable association between somatic symptoms and mental health comorbidities, particularly anxiety and depression, which can influence the prognosis​​​​.