F40.0 Agoraphobia

The term "agoraphobia" is used here with a wider meaning than it has when originally introduced and as it is still used in some countries. It is now taken to include fears not only of open spaces but also of related aspects such as the presence of crowds and the difficulty of immediate easy escape to a safe place (usually home). The term therefore refers to an interrelated and often overlapping cluster of phobias embracing fears of leaving home: fear of entering shops, crowds, and public places, or of travelling alone in trains, buses, or planes. Although the severity of the anxiety and the extent of avoidance behaviour are variable, this is the most incapacitating of the phobic disorders and some sufferers become completely housebound; many are terrified by the thought of collapsing and being left helpless in public. The lack of an immediately available exit is one of the key features of many of these agoraphobic situations. Most sufferers are women and the onset is usually early in adult life. Depressive and obsessional symptoms and social phobias may also be present but do not dominate the clinical picture. In the absence of effective treatment, agoraphobia often becomes chronic, though usually fluctuating.

Diagnostic Guidelines

All the following criteria should be fulfilled for a definite diagnosis:

(a) the psychological or autonomic symptoms must be primarily manifestations of anxiety and not secondary to other symptoms, such as delusions or obsessional thoughts;
(b) the anxiety must be restricted to (or occur mainly in) at least two of the following situations: crowds, public places, travelling away from home, and travelling alone; and
(c) avoidance of the phobic situation must be, or have been, a prominent feature.

Differential Diagnosis
It must be remembered that some agoraphobics experience little anxiety because they are consistently able to avoid their phobic situations. The presence of other symptoms such as depression, depersonalization, obsessional symptoms, and social phobias does not invalidate the diagnosis, provided that these symptoms do not dominate the clinical picture. However, if the patient was already significantly depressed when the phobic symptoms first appeared, depressive episode may be a more appropriate main diagnosis; this is more common in late-onset cases.

The present or absence of panic disorder in the agoraphobic situation on a majority of occasions may be recorded by means of a fifth character