Overlapping and distinctive features of hypochondriasis and obsessive-compulsive disorder.

The spectrum of obsessive-compulsive disorders has received a great deal of theoretical attention, but there has been relatively little associated empirical research. The purpose of this study was to compare three groups of patients; those diagnosed with hypochondriasis (HC, a proposed spectrum condition), obsessive-compulsive disorder (OCD) and those with both OCD and HC (OCD/HC). The results show that patients with HC scored highest on a measure of overvalued ideas, and that the HC and HC/OCD groups scored significantly higher on measures of panic and agoraphobic cognitions. The groups also differed significantly for symptoms associated with compulsions. The patient groups were not different for measures of obsessions, depression, and anxiety. The results provide partial support for inclusion of HC in the spectrum of obsessive-compulsive disorders, but also provide indirect support for the association between HC and panic disorder. These results are interpreted in light of distinguishing characteristics among obsessive-compulsive spectrum conditions.