Download Phobic disorders - Brisbane North PHN

Phobic disorders
Introduction
Phobic disorders are characterised by intense fear of an object(s) or situation(s), which:
• is out of proportion to the apparent stimulus
• cannot be explained or reasoned away
• leads to avoidance of the object or situation.
These disorders may be named for the nature of the situation or object, eg agoraphobia, social phobia (social anxiety disorder), specific
phobia.
For all phobic disorders, treatment should generally be with psychological interventions (eg cognitive behavioural therapy).
Agoraphobia
Agoraphobia is the fear and avoidance of being in places or situations from which escape might be difficult or embarrassing (eg
theatre, public transport, queues), or in which help might not be available in the event of suddenly developing a symptom that could be
incapacitating or embarrassing (eg dizziness, derealisation, loss of bladder or bowel control, or a panic attack). As a result of this fear,
the person either restricts activities, or endures agoraphobic situations despite intense anxiety.
The majority of people with agoraphobia (90%) develop this as a response to the onset of recurrent panic attacks. Treatment involves the
control of panic attacks and then, once anxiety is sufficiently reduced, behavioural therapy with graduated in vivo exposure to overcome
the phobic avoidance. See Panic disorder for drugs that are effective for panic disorder.
When agoraphobia develops without associated panic attacks, pharmacotherapy is usually not indicated.
Social anxiety disorder (social phobia)
Social anxiety disorder, also known as social phobia, is a persistent fear of one or more social or performance situations in which the
person is exposed to possible scrutiny by others (eg speaking in public), anticipates that they will be negatively evaluated by others, and
fears that they may say something or act in a way that is humiliating or embarrassing. The phobic situation(s) is avoided or is endured
with intense anxiety or distress. There are two subtypes of this disorder:
• generalised social anxiety—fear of numerous social situations, including both performance and interactional situations
• non-generalised social anxiety—fear of one or just a few situations of performance type.
Treatment is quite different for the two types of social anxiety disorder.
Treatment of generalised social anxiety disorder
In generalised social anxiety disorder, cognitive behavioural therapy (CBT) incorporating exposure-based therapy, social skills training
and cognitive therapy is the treatment of choice. However, for many people CBT alone is not sufficient to reduce symptoms to a
manageable level, so a combination of pharmacotherapy and psychological intervention is needed.
Three groups of drugs have shown efficacy in the symptomatic relief of generalised social anxiety disorder: selective serotonin reuptake
inhibitors (SSRIs), irreversible nonselective monoamine oxidase inhibitors (MAOIs) and venlafaxine.
Pharmacotherapy for social anxiety disorder may need to be continued for 6 to 12 months in the first instance. After this period, the
dose should be slowly reduced and, if possible, the drug stopped. Every effort should be made to use psychological interventions to
minimise the need for prolonged pharmacotherapy. However, some patients need ongoing medication. Re-emergence of symptoms may
be reduced, and the chance of successfully ceasing the drug increased, if the patient can effectively use CBT concurrently.
When a drug is needed, SSRIs are the treatment of choice. If this is not effective, try venlafaxine. If considered appropriate, use:
1 an SSRI orally, see Table 8.1*
OR
2 venlafaxine controlled-release 75 mg orally, in the morning after food, increasing according to tolerability and patient response.
Maximum dose 225 mg daily.
Many regard MAOIs as the most powerful pharmacotherapy for generalised social anxiety disorder. Their use is generally restricted to
specialist psychiatric practice because MAOI use is complicated by their adverse effect profile, significant interactions with many other
drugs and the need to avoid all foods containing tyramine (see Table 8.22). For phenelzine, a commonly used dosage range is 45 to 60
mg daily in 2 to 3 divided doses, up to a maximum of 90 mg daily. The last dose each day should be given no later than early afternoon
to minimise the risk of insomnia.
*At the time of writing, citalopram, fluoxetine and fluvoxamine are not approved by the Australian Therapeutic Goods Administration (TGA) for treatment of
generalised social anxiety disorder. See the TGA website <www.tga.gov.au> for current information.
Therapeutic Guidelines Limited (www.tg.org.au) is an independent not-for-profit organisation dedicated to deriving guidelines for therapy from the latest world literature, interpreted
and distilled by Australia’s most eminent and respected experts.
Reproduced with permission from Psychotropic Expert Group. Phobic disorders [revised 2013].
In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited; 2013.
Phobic disorders
Treatment of non-generalised social anxiety disorder
Control of hyperventilation and other measures to deal with panic symptoms, together with cognitive strategies, form the basis of
psychological interventions for non-generalised social anxiety disorder (including performance anxiety).
The goal of pharmacotherapy is to reduce the specific physiological symptoms (manifestations of sympathetic overactivity) of tremor,
palpitations and sweating, which are distressing or unpleasant during a particular task. Beta blockers are widely used for this purpose.
To assess any possible adverse effects, advise patients to take a trial dose at home before they take a dose to reduce symptoms in a social
situation. Use:
propranolol 10 to 40 mg orally, 30 to 60 minutes before the social event or performance.
Propranolol should be avoided in patients with asthma or severe peripheral vascular disease and some patients with heart failure. It
should be used cautiously in patients with diabetes. Propranolol does not directly relieve the mental aspects of social phobia.
A short-acting benzodiazepine taken just before the performance situation may be an option. However, adverse effects include sedation,
impaired coordination, or disinhibition, all of which may impair performance. If prescribing a benzodiazepine consider the precautions
listed in Anxiety and associated disorders: general information and issue a prescription for a limited supply.
Specific phobias
Specific phobias are divided into four subgroups: animal type (eg dogs, moths, birds); natural environment type (eg heights, storms,
water, lightning); blood-injury injection type; and situational type (eg aeroplanes, lifts and enclosed spaces).
For specific phobia there is almost no place for ongoing pharmacotherapy.
Occasionally the specific phobia is so severe that the patient cannot overcome it with psychological interventions alone. In these
circumstances there may be some help in using diazepam for a brief period until some control is achieved over the phobia.
Pharmacotherapy may also be useful in situations where a specific phobia needs to be overcome for a particular event or at a particular
time. A common example is the need to manage a phobia of enclosed spaces (claustrophobia) in a patient who requires a magnetic
resonance imaging (MRI) examination. In this type of situation, diazepam can be given as a single dose before the examination to control
anxiety.
Therapeutic Guidelines Limited (www.tg.org.au) is an independent not-for-profit organisation dedicated to deriving guidelines for therapy from the latest world literature, interpreted
and distilled by Australia’s most eminent and respected experts.
Reproduced with permission from Psychotropic Expert Group. Phobic disorders [revised 2013].
In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited; 2013.