22 - Phobic anxiety disorders

Phobic anxiety disorders

© SPMM Course primary diagnosis, with panic disorder being a qualifier for subcategorisation, in addition to being a diagnostic entity on its own but to be used only when no phobic disorder is notable. Phobic anxiety disorders According to Marks, the cardinal features of phobia include  the  ‘fear’  which  (1) Is out of proportion to the situation (2) Cannot be explained or reasoned away (3) Is beyond voluntary control (4) Leads to avoidance. Phobic anxiety is subjectively and behaviourally indistinguishable from other anxieties. Anticipatory anxiety is an important feature. Note that the phobic object is almost always external and not ‘currently dangerous’ for the patient. Internal phobic objects are noted in conditions such as nosophobia and dysmorphophobia; these conditions are classified under hypochondriasis. The circumstances provoking anxiety include situations (for example crowded places), objects like cockroaches and natural phenomena like thunder. The common types of phobic syndromes are agoraphobia, social phobia and specific (simple) phobias. Agoraphobia Agoraphobia is the commonest phobic disorder seen by psychiatrists. Agoraphobia is considered to be the most incapacitating of all phobias, with a lifetime prevalence of about 6-10% (Weismann and Merikangas 1986). It is more common in women between the age group of 15-35 and most cases begin in the early or midtwenties, though there is a further period of high onset in the mid-thirties. In later life, agoraphobic symptoms may develop secondary to physical frailty, with the associated fear of exacerbating medical problems or having an accident. The first episode typically occurs when a person (often a woman) is waiting for public transport or shopping in a crowded supermarket. Lack of immediately available escape route or exit is the main cognitive basis for the anxiety seen in agoraphobia. The three common themes that provoke anxiety and avoidance are of distance from home, crowding and confinement. Anticipatory anxiety can start even hours before the patient enters the feared situation. Avoidance of crowds, public places, or travelling away from home or being alone is a common feature. . Patients remain symptoms free if avoidance is successful. Symptoms usually fluctuate. It is not uncommon for agoraphobics to become totally housebound and, therefore, is sometimes called as housebound housewife syndrome, although not all patients with this condition are necessarily housewives. Agoraphobia may be accompanied by panic attacks, whether in response to environmental stimuli or arising spontaneously.

© SPMM Course As highlighted earlier, ICD-10 considers agoraphobia as the primary disorder with panic attacks being secondary and indicate severity of agoraphobia. The opposite is true in DSM-IV (but this issue has been resolved in DSM-V: see the box above). In cases where depression starts earlier, a diagnosis of depressive disorder should suffice, especially in late onset agoraphobia. Social Phobias Social phobia occurs more in small group settings where close scrutiny is possible. Two types of social phobia are noted in ICD-10 - (1) discrete type – anxiety manifested seen in specific occasions e.g. shy bladder (when using a public toilet) or fear of public speaking or (2) diffuse type – seen with exposure to any generic social task. Fear of vomiting in public is seen in some with social phobia. Blushing is also more common in social phobia than other anxiety disorders. The condition usually begins between the ages of 17 and 30. The first episode occurs in a public place, usually without any apparent reason. DSM describes social phobia as a marked and persistent fear of one or more social or performance situations where one gets exposed to unfamiliar people or to possible scrutiny by others. DSM also specifies the fear of humiliating or embarrassing oneself as an important feature, which helps to differentiate it from the anxiety seen in social situations when someone is paranoid. In addition, DSM stipulates that the sufferer must also recognize that the fear is excessive or unreasonable. DSM-IV specifies that in children, difficult social situations should involve interactions with peer, but an appreciation of the unreasonable or excessive nature of the fear is not required. A duration criteria of 6 months is also specified only for children, not adults. Specific phobias The age of onset of most specific phobias is in childhood; phobia of animals at average age of 7, blood phobia at 9, dental phobia at 12 (Ost, 1987) and claustrophobia -20yrs. It is more common among women. DSM-IV distinguishes 5 subtypes of phobias: animals, aspects of the natural environment, blood/injection/injury, situational, and other provoking agents. Specific phobia does not usually fluctuate and remain constant. Disease phobia related to situations where disease can be acquired and so avoided is still a specific phobia (nosophobia) and not hypochondriasis. Blood injury injection phobia is different from other phobias in that the response to exposure is not tachycardia and sympathetically driven heart rate, etc. Instead, a fainting response occurs where the DSM-5 AND SPECIFIC PHOBIAS In adults, there is no requirement for a subjective recognition that the fear is excessive or unreasonable. For all ages, duration of 6 months or more is applied.