14th February 2025

Somatic symptom disorders

Overview of somatic symptom disorders

These controversial and poorly understood psychiatric disorders feature a complex interplay of physical symptoms, thoughts, emotions and behaviours. The patient presents with an otherwise medically unexplained physical symptom, which is thought to be caused by underlying psychological distress.

They are distinct from syndromes that involve deliberate falsification of symptoms, either for material gain (malingering) or for the psychological reward of occupying the sick role (factitious disorder, also known as Munchausen’s syndrome).

They can result in significant distress and functional deficits. Although the physical symptom may not have a traditional medical cause, the distress and suffering is always real.

Risk factors include female sex, specific personality traits (‘repressed’, i.e. reduced ability to express or describe emotion, ‘distressed’ or ‘neurotic’, i.e. increased tendency to experience negative emotions), recent or past stressors (including childhood abuse), and trauma-related psychiatric illness, e.g. PTSD, dissociative disorder.

Diagnosis of somatic symptom disorders

Presentation of somatic symptom disorders

The presence of a medically unexplained physical (or ‘somatic’) symptom is not sufficient for diagnosis. It must be accompanied by a set of maladaptive cognitive, emotional and behavioural responses for the diagnosis to apply. These responses may perpetuate or emphasise the physical symptom. 

The DSM-5 requires all three of the following criteria to be met for diagnosis of somatic symptom disorder:

• Presence of physical symptom(s) that cause distress or disruption to daily life 
• Thoughts, anxiety or time/energy spent in relation to the symptom(s), which is excessive for severity
• A continuous symptomatic state, usually for at least 6 months, even if no single symptom is continuous for this time (i.e. different symptoms may feature across this period)

The most well-known examples of somatic symptom disorders involve symptoms in the neurological domain:

• Conversion disorder: sensory or motor function deficit, e.g. limb paralysis, vision loss
• Non-epileptic seizures, also known as pseudoseizures, functional or psychogenic seizures

However, somatic symptom disorders can affect any organ system and can be non-specific. For example, unexplained cough, swallowing difficulty, abdominal pain, nausea or tiredness. Terminology is often controversial and multiple in relation to these disorders, as in the case of non-epileptic seizures, due to varying and controversial focus on the psychological origin of the condition.

Examination in somatic symptom disorders

This varies according to the symptom. In conversion disorder, examination reveals ‘pseudo-neurological’ signs:

• Variability, e.g. movement disorders with erratic patterns of movement
• Distractibility: variation in symptoms when the patient’s attention is directed elsewhere
• Inconsistency, e.g. leg weakness on formal examination that does not limit mobility as much as expected
• Unusual distribution, not in keeping with physiology, e.g. motor deficit in an abnormal distribution

Investigations in somatic symptom disorders

Somatic symptom disorder is a diagnosis of exclusion: there is no diagnostic test for it. Instead, clinicians need to first search for any objectively measurable medical conditions that could explain the condition.

The extent of investigations will heavily depend on the organ system involved. Conversion disorder is one of the best understood somatic symptom disorders because objective neurological testing is more readily available than in other body systems. For example, nerve conduction studies and electromyogram (EMG) can objectively demonstrate functional peripheral nerves and muscles to rule out disorders originating there. Video-EEG can objectively capture or rule out epileptic seizures.

Management of somatic symptom disorders

The dynamic of the doctor-patient relationship is key, including empathy for the patient’s suffering and demonstrating trust that the patient is not faking symptoms. It is also a necessary foundation for setting clear boundaries to avoid unnecessary investigations or treatments. If indulged, these can perpetuate the patient’s maladaptive response to the physical symptom and may cause harm in other ways, e.g. radiation exposure.

Cognitive behavioural therapy will help the patient to develop coping strategies and self-modulation of cognitive, emotional and behavioural responses to the physical symptom. Any other psychiatric conditions should also be treated. Physical therapy may also have a role.

References

• O’Sullivan S. It’s all in your head: true stories of imaginary illness. London: Vintage Books; 2016
• Stonnington C, Driver-Dunckley E, Noe K, Locke D. Conversion and somatic symptom disorders – Symptoms, diagnosis and treatment. [Internet]. BMJ Best Practice. 2021 [cited 2022 Apr 10]. Available from: https://bestpractice.bmj.com/topics/en-gb/989