Specific phobia of illness makes its appearance in DSM-IV as a new diagnostic subtype, separate from hypochondriasis. A review of the literature indicates that, while there is some support for this new category, studies have not as yet been done that could provide validation. Illness phobia appears to be a significant problem; it is prevalent in the general population and is associated with distress and impairment, including interference with medical care. It appears to be associated with older age, physical illness, and female gender. Group comparisons are needed showing that persons with this phobia can be distinguished from hypochondriasis on the basis of these and other demographic and illness features. We outline a research agenda for demonstrating this separation.
Illness phobia first appears in DSM-IV under the heading of specific phobia, other type (American Psychiatric Association, 1994). There it is defined as an unreasonable fear of contracting a disease and distinguished from hypochondriasis. According to this classification, illness phobics fear developing a disease they do not have, whereas persons with hypochondriasis are preoccupied with a disease they believe is already present (American Psychiatric Association, 1991). Phobia of illness is prevalent in the general population and may cause significant distress, impairment, and interference with medical care (Agras, Sylvester, & Oliveau, 1969). Even so, it has been neglected in the medical literature. Marks (1970) included this fear in his classification of phobias but expressed uncertainty about its status. Now that illness phobia is in the official classification, it seems appropriate to reassess its standing. In doing so, we addressed several questions. How is specific phobia of illness to be characterized? Does it exist apart from other disorders? And what research is needed to clarify its position?
At issue is whether specific phobia of illness can be distinguished from hypochondriasis. Early group comparison and factor analytic studies established separate dimensions of disease phobia and disease conviction within hypochondriasis (Kellner, 1985 and Pilowsky, 1967), and both DSM-III and DSM-III-R included them in criterion A (American Psychiatric Association, 1980 and American Psychiatric Association, 1987). A decision to recognize separate disorders was based upon a review of the literature and unpublished data suggesting that these dimensions represent phenomenologically distinct syndromes (Cote et al., 1996; Salkovskis, Warwick, & Clark, 1990). Nevertheless, experts in the field do not agree. Marks (1987), for example, views illness phobia as a subtype of hypochondriasis. The illness phobic, according to this author, persistently focuses on a single symptom or illness, whereas the hypochondriac is concerned with multiple bodily symptoms or illnesses. Barsky (1992) sees disease phobia and disease conviction as possible subgroups of hypochondriasis. He observes that patients with prominent disease phobia present like those with anxiety disorders and have more insight into the psychological nature of their disturbance. Patients with disease conviction present more of a depressive picture. They are preoccupied with somatic symptoms and are more convinced of being ill than afraid of developing illness.
