A systematic review of the epidemiology of somatisation disorder and hypochondriasis.

BACKGROUND: This paper reviews current knowledge regarding the prevalence and associated features of somatisation disorder and hypochondriasis in population-based and primary care samples.

METHOD: A systematic review of the literature, which used a standardised definition of somatisation disorder or hypochondriasis and which examined the characteristics and associated features of these disorders in population-based samples or primary care settings.

RESULTS: In population-based studies the prevalence of somatisation disorder and hypochondriasis was too low to examine associated features reliably. In studies using abridged criteria, a clear female predominance was not found in either disorder; there was a consistent relationship with few years of education. There was a close relationship with anxiety and depressive disorders, with a linear relationship between numbers of somatic and other symptoms of distress in several studies, including longitudinal studies. No studies showed that these symptom clusters fulfil the criteria of characteristic onset, course and prognosis required to merit the status of discrete psychiatric disorders.

CONCLUSIONS: On existing evidence, somatisation disorder and hypochondriasis cannot be regarded as definite psychiatric disorders. There is some evidence that numerous somatic symptoms or illness worry may be associated with impairment and high health care utilisation in a way that cannot be solely explained by concurrent anxiety and depression, but further research using population-based samples is required.