The Boundary Between Hypochondriasis and Obsessive-Compulsive Disorder

Abstract

To investigate similarities and differences between the symptom profiles of patients with hypochondriasis and those of patients with obsessive-compulsive disorder (OCD) and to compare the contamination/cleaning OCD subtype to other OCD subtypes. Between January 1998 and July 2002, 76 patients diagnosed with hypochondriasis (N = 31) or OCD (N = 45) (DSM-IV criteria) and 25 subjects with no formal DSM-IV diagnosis were compared with regard to the extent of diagnosis-specific symptoms, the number and nature of physical symptoms, and whether these symptoms evoked fear. The analyses were repeated after subdividing the OCD patients into the contamination/cleaning and other OCD subgroups. Patients with hypochondriasis and OCD differed significantly from each other on the extent of diagnosis-specific symptoms (all p < .001). Patients with hypochondriasis reported significantly more obsessive-compulsive symptoms and patients with OCD reported significantly more hypochondriacal symptoms than did the healthy control-group members (all p < .05). Neither group differed significantly from the other on the number and nature of feared physical symptoms. The contamination/cleaning OCD subtype did not differ significantly from other OCD subtypes in either the severity of hypochondriacal symptoms or the number of feared physical symptoms. Hypochondriasis and OCD can be distinguished on the basis of diagnosis-specific symptoms, although they share a number of similarities. In addition, although patients with the contamination/cleaning OCD subtype tend to be afraid of contracting diseases, the differences between the symptom profiles of these patients and those of patients with hypochondriasis exceed the similarities. Our results confirm that the 2 conditions are separable and valid diagnoses.