The relationship of hypochondriasis to anxiety disorders.

There is evidence from the literature of phenomenological overlap between hypochondriasis and several anxiety disorders, including specific phobia, panic disorder with agoraphobia, generalized anxiety disorder, and obsessive-compulsive disorder. Even though the boundaries of these disorders are specifically addressed in the DSM-IV criteria, there is evidence of anxiety and phobic symptoms among hypochondriacal patients and hypochondriacal concerns among patients with these various anxiety disorders. Beyond that there appears to be considerable shared comorbidity. However, the data remain limited and few direct comparisons have been made between hypochondriacal and anxious patients belonging to particular diagnostic categories. Subtypes of hypochondriasis may exist. In fact, the clearest link would seem to be between the illness phobia subtype and other phobic disorders, although this subgroup has had little study. Thus, hypochondriasis is distinct from the anxiety disorders but, because of phenomenological similarities and extensive comorbidity, consideration should be given to classifying it among them.