Objective: The objective of this study was to assess the prevalence of chronic fatigue (CF) and its association with somatization syndrome [Somatization Syndrome Index (SSI) 4/6: >/=4 somatoform symptoms in men, 6 in women] in the general population.
Methods: A representative sample of the German population (N=2412) completed a fatigue questionnaire and a screening instrument for current somatoform symptoms (Screening for Somatoform Symptoms 7).
Results: The prevalence rate of CF was 6.1% (n=147). Females were affected significantly more often as compared with males (7% vs. 5.1%). The mean number of somatoform symptoms was higher in CF cases than in control subjects without CF (11 vs. 2; P<.001). Seventy-two percent of the subjects with CF fulfilled the SSI4/6 criterion for somatization syndrome. Quality of life (EUROHIS-QOL and 8-item Short-Form Health Survey) and well-being (5-item WHO Well-Being Index) were markedly decreased in CF and SSI4/6. The results of regression analyses suggest that fatigue and somatization severity had a similar impact on quality of life.
Conclusions: The results suggest that CF is relevant in the general population. Its substantial overlap with somatization syndrome supports the hypothesis that the two syndromes are only partially different manifestations of the same underlying processes.