Course of hypochondriasis in an international primary care study.

Hypochondriasis is frequently defined as a chronic condition distinct from anxiety and depressive disorders. Consecutive primary care attenders (n=25,916) were screened using the General Health Questionnaire and a stratified random sample (n=5447) completed a baseline diagnostic assessment. All patients with significant psychiatric symptoms and a random sample of remaining patients (n=3201) were asked to complete a follow-up diagnostic assessment 12 months later. Of patients meeting an abridged definition of hypochondriasis at baseline, 18% continued to do so at follow-up and an additional 16% continued to report hypochondriacal worries. 45% of those with hypochondriasis at follow-up also met criteria for DSM-IV anxiety or depressive disorder. Follow-up anxiety or depressive disorder was significantly associated with both onset and persistence of hypochondriasis. Hypochondriasis is moderately stable over time. The clear distinction between hypochondriasis and anxiety/depressive disorders suggested by ICD-10 and DSM-IV may be difficult to accomplish in practice.