Panic disorder: fact or fiction?

It has been known for many years that acute attacks of anxiety can occur in the course of anxiety and depressive disorders. For example, in 1879 Maudsley described anxiety attacks in severe depressive disorders (Maudsley, 1879, p. 365) and in 1893 Hecker pointed out their association with the less severe forms of depression and anxiety known as neurasthenia. Hecker also described anxiety attacks in which physical symptoms were more prominent than psychological ones. Cases of this kind were studied mainly by physicians, many of whom suspected a cardiac origin and used terms such as disorderly action of the heart or effort syndrome. Freud made similar observations in a frequently quoted paper on anxiety neurosis published in 1895. In recent years, the interest of psychiatrists in anxiety attacks has revived. The term panic attack is now preferred, and a distinction (recognized by Hecker) is made between spontaneous and situational attacks. Patients with severe and frequent panic attacks, at least some of which are spontaneous, are now classified as panic disorder, and it is suggested that this disorder is distinct from most other anxiety disorders (the exception being agoraphobia). Furthermore, it is proposed that panic disorder has a specific neurochemical cause, and requires a particular kind of pharmacological treatment. Agoraphobia, it is suggested, is not a distinct diagnostic entity, but a variant of panic disorder in which anticipatory anxiety, situational anxiety, and avoidance behaviour have developed. These new ideas have been accepted widely in the United States, but they have been received more cautiously in the United Kingdom. How well are they supported by evidence? Four claims will be examined here: that spontaneous panic attacks differ from situational panic attacks; that panic disorder is separate from other forms of anxiety disorder; that agoraphobia is a secondary development of panic disorder; and that panic disorder has a 'biological' aetiology. A fifth issue, the relationship of panic disorder to depressive disorder, cannot be considered in the space of this review. In most reviews, apparently complex issues are reduced to simpler ones. In this review, the conclusion will be that the situation is considerably more complicated than these four claims would suggest.