Prevalence of somatoform disorders and medically unexplained symptoms in old age populations in comparison with younger age groups: a systematic review.

OBJECTIVE: To review current knowledge regarding the prevalence of somatization problems in later life by level of caseness (somatoform disorders and medically unexplained symptoms, MUS) and to compare these rates with those in middle-aged and younger age groups.

METHOD: A systematic search of the literature published from 1966 onwards was conducted in the Pubmed and EMBASE databases.

RESULTS: Overall 8 articles, describing a total of 7 cohorts, provided data of at least one prevalence rate for somatoform disorders or MUS for the middle-aged (50-65 years) or older age (≥65 years) group. Prevalence rates for somatoform disorders in the general population range from 11 to 21% in younger, 10 to 20% in the middle-aged, and 1.5 to 13% in the older age groups. Prevalence rates for MUS show wider ranges, of respectively 1.6-70%, 2.4-87%, and 4.6-18%, in the younger, middle, and older age groups, which could be explained by the use of different instruments as well as lack of consensus in defining MUS.

CONCLUSION: Somatoform disorders and MUS are common in later life, although the available data suggest that prevalence rates decline after the age of 65 years. More systematic research with special focus on the older population is needed to understand this age-related decline in prevalence rates.