Introduction/Objectives: Hypochondriasis has been associated with several anxiety disorders, especially with panic disorder (PD). It is estimated that 50% to 70% of PD patients have hypochondriacal symptoms and 13% to 17% of patients with hypochondriasis have associated PD. The objective of this study was to review the literature on clinical, phenomenological, cognitive and psychodynamic relationships between PD and hypochondriasis, and to discuss conceptual aspects and diagnostic criteria. Methods: A Medline search was conducted between 1990 and 2001 using the following keywords: panic disorder, agoraphobia, hypochondriasis, and hypochondriacal concerns. Results: It is considered hypochondriasis comorbidity in PD only when health worries are not restricted to panic attack symptoms. Although usually regarded as a secondary phenomenon, hypochondriacal preoccupations precede the first panic attack in many PD patients and may be considered prodromal symptoms. In a vicious circle, anxiety may lead to excessive health worries, selective self-observation and anticipation of the worst outcomes. Though a catastrophic bias is common to both diseases, in PD the autonomic symptoms increase rapidly culminating in a panic attack, and the dread catastrophe seems to be imminent, leading to avoidant behaviors and immediate quest for help. Hypochondriasis is characterized by a fear of more insidious diseases, hypervigilance, search for reassurance behaviors, more dysfunctional beliefs, poorer doctor-patient relationship, and a wider range of feelings misinterpreted as catastrophic. Pathological fear of death and alexithymia may play an important role in both disorders. Conclusions: The clinical overlapping of PD/agoraphobia and hypochondriasis is significant but not complete. The relationship between the two disorders is complex and possibly bidirectional, both increasing their mutual vulnerability. There are identifiable and important phenomenological differences with implications for diagnosis and treatment.
Panic disorder; Agoraphobia; Hypochondriasis; Neurosis, hypochondriacal; Diagnosis, differential; Comorbidity
