Epidemiology and Demographics of Hypochondriasis

Although there are no prevalence figures for hypochondriasis in the general population, its prevalence in a medical practice, it has been estimated, ranges from 4 to 9% (APA, 1994). It has been estimated that from 60 to 80% of the normal population will experience, on average, at least one physical symptom in a given week. Using a more restrictive definition, hypochondriasis, it has been noted, occurs in 3 to 14% of patients seen in medical settings. Using DSM-III-R diagnostic criteria, Barsky, Wyshak, Klerman, and Latham found that the 6month prevalence rate of hypochondriasis falls between 4.2 and 6.3% in a tertiary academic medical setting.

Based on a screening scale, the prevalence of hypochondriasis was 14% in a general medical clinic. Hypochondriasis occurs equally among men and women. With respect to course, hypochondriacal symptoms tend to wax and wane over a long period of time. Until recently, much of what was known about hypochondriasis was based on Kenyon’s classic study of 1964. Kenyon reviewed case records of all patients who attended Bethlem Royal and Maudley hospitals during a 10-year period from 1951 to 1960. A total of 512 patients was identified and characterized as either primary (hypochondriasis was the only complaint) or secondary (hypochondriasis was secondary to a preexisting disorder) hypochondriacs. He classified somatic complaints according to the distribution of symptoms in different parts of the body, physiological systems affected, and whether symptoms were unilateral or bilateral. The areas most commonly reported to be of hypochondriacal focus were the head, neck, abdomen, and chest, in that order. Musculoskeletal, gastrointestinal, and central nervous system areas were the bodily systems most involved. Pain (e.g., headache, chest pain, backache, and abdominal pain), the most common symptom reported, occurred in approximately 70% of the entire sample. Seventy-three percent of the whole sample reported symptoms primarily on the left side of the body. No striking differences in age, sex, religion, social class, marital status or relevant clinical variables were found between primary hypochondriacs (N = 301) and secondary hypochondriacs (N = 211). Among 295 patients subsequently admitted for inpatient hospitalization, Kenyon found an absence of significant physical abnormality in 47% of these cases, and in approximately one-half of these cases, no precipitating factors were noted.

The onset of hypochondriasis, it is believed, occurs as early as childhood or as late as senescence, but more commonly by early adulthood. Kenyon found that the overall peak age of incidence for hypochondriasis was 30 to 39 years of age; the peak for males was in the 30 to 39 age group, and the peak for females was in the 40 to 49 age group.