Wessely, Nimnuan, & Sharpe (1999). Functional somatic syndromes: One or many? – Article summary

Symptoms are the patient’s subjective experience of changes in one’s body. Diseases are objectively observable abnormalities in the body. Medically unexplained or functional symptoms are symptoms for which no biological basis can be found. It is possible that the differentiation between specific functional syndromes reflects the specialist’s tendency to focus on symptoms relevant to their speciality.

Functional symptoms are common, persistent and associated with significant distress, disability and unnecessary expenditure of medical resources. The prevalence of emotional distress and disorder in patients who attend hospital with functional syndromes is higher than patients with comparable medical conditions.

There is substantial overlap in the case definitions of specific functional somatic syndromes. Patients with one functional syndrome often meet diagnostic criteria for other syndromes. Almost all functional syndromes are more common in women than in men. The exceptions are chest pain and difficulty walking.

There is a strong association between the range of functional somatic symptoms and psychological distress. The number of functional complaints is related to past episodes of anxiety and depression.

There is a link between functional somatic syndromes and altered functioning of the central nervous system. Childhood physical and in particular, sexual abuse, is more common in women with functional syndromes. Dissatisfaction with medical care is common among patients with functional syndromes.

Treatment for functional syndromes is mostly focused on rehabilitation rather than a cure.  Antidepressant treatment appears to be effective for some functional syndromes although it is not completely clear why it is effective. Psychological therapy (e.g. cognitive behavioural therapy) appears to be effective for most functional syndromes. All functional syndromes appear to respond to the same therapies.

There may be four approaches to subclassify patients with functional syndromes:

1. Clustering in existing case definitions
2. Using epidemiological data
3. Subclassify functional somatic syndromes in depressive, anxiety and somatoform disorders
4. Multiaxial approach (i.e. employing multiple axis of diagnostic descriptions).