Features of Hypochondriasis and Illness Worry in the General Population in Germany

Abstract
Objective: Although hypochondriasis is considered to be of high relevance in the healthcare sector, its prevalence in the general population has been investigated in few studies. The aims of this study were to estimate prevalence rates of hypochondriasis and of subthreshold conditions and to describe their associated features such as quality of life and healthcare utilization in a representative community sample. Methods: Analyses of the present study are based on the German Health Interview and Examination Survey–Mental Health Supplement (N = 4181, representative for the German population from 18–65 years). The assessment included interviews for somatic conditions and mental disorders and self-report ratings on health-related quality of life, healthcare utilization, disability days, and physical activity. Results: Only three cases (0.05%) were identified as meeting full criteria of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) hypochondriasis. The prevalence rate of the less restrictively defined form of hypochondriasis, (“subthreshold hypochondriasis”) was 0.58% and an additional 2.12% reported having had illness worries for at least 6 months but did not meet further hypochondriasis criteria. The two subthreshold diagnostic groups provided strong evidence of difference from the nonhypochondriac controls: comorbidity with psychiatric and medical disorders and healthcare utilization were higher, and quality of life was markedly reduced. Conclusions: The results provide additional support to not only consider “full” DSM-IV hypochondriasis, which is a very rare disorder in the general population, but also to include less restrictive hypochondriac conditions—associated with a clinically relevant degree of psychological and physical impairment—into clinical and scientific considerations. DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; GHS = The German National Health Interview and Examination Survey; GHS-CS = core survey; GHS-MHS = mental health supplement; H0 = no illness worry group; H1 = unrealistic illness worry group; H2 = subthreshold hypochondriasis; M-CIDI = Munich Composite International Diagnostic Interview.