Background. The nature and correlates of hypochondriasis are still poorly understood, especially in settings other than those in North America and Western Europe.

Methods. A total of 25916 consecutive patients making ambulatory visits to primary care clinics at 15 sites in 14 countries were screened using the 12-item General Health Questionnaire (GHQ-12). Based on the screen-score performance, a stratified sample of 5447 of respondents was evaluated at the second-stage (response rate: 62%). Evaluation consisted of physician-rated physical and psychological health status and self-ratings of overall health, physical disability and GHQ-28. Interviewers conducted assessment of psychiatric status, using the Composite International Diagnostic Interview (CIDI) and occupational disability.

Results. Across the sites, the occurrence of ICD-10 hypochondriasis was 0·8% (95% Confidence Interval, 0·5–1·0%) and over 1·5% at only two sites. A less restrictively-defined form of the disorder had a pooled frequency of 2·2% (95% Confidence Interval, 1·8–2·6%) across the sites. Patients with this abridged hypochondriasis were more likely than those without to have co-morbid major depression and generalized anxiety disorder. They had a poorer perception of their health, were more physically disabled, were more impaired in the performance of occupational role, and were above-average utilizers of health service. Patients with ICD-10 hypochondriasis were no more impaired than those with abridged hypochondriasis.

Conclusion. Even though the ICD-10-defined hypochondriasis is rare, a form consisting of the triad of disease conviction, associated distress and medical help-seeking is present in primary-care settings in different cultures. This syndrome is associated with considerable psychiatric ill-health and functional disability.