AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

A phobia is defined as an irrational fear that produces a conscious avoidance of the feared subject, activity, or situation. The affected person usually recognizes that the reaction is excessive. Phobic disorders can be divided into 3 types: social phobia, specific phobias, and agoraphobia.

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)¹ and its subsequent Text Revision (DSM-IV-TR) defines social phobia as a strong, persisting fear of an interpersonal situation in which embarrassment can occur and specific phobia as a strong, persisting fear of an object or situation. Agoraphobia is defined as the fear of being alone in public places (eg, a supermarket), particularly places from which a rapid exit would be difficult in the course of a panic attack. At least 75% of patients with agoraphobia experience panic disorder as well.

Social phobia, now called social anxiety disorder (SAD), has been described as far back as Hippocrates, when it was called erythrophobia, which is a fear of blushing in front of others. Social anxiety disorder is now considered a disorder distinct from other phobias. In the first 2 versions of the DSM, social phobia was not conceptualized as a stand-alone diagnosis; however, starting with DSM-III-R, the disorder could be diagnosed separately in the presence of multiple social fears and other comorbid conditions.

Specific phobia is more common than social phobia. The following types of specific phobia are described:

• Animal type (fear of dogs, spiders, snakes, or other animals)
• Natural environment type (eg, height, water, storm)
• Blood injection/injury type
• Situational type (eg, planes, elevators, enclosed spaces)
• Other

Collectively, these disorders are the most common forms of psychiatric illness, surpassing rates of mood disorders and substance abuse. Anxiety linked to a specific object or situation is the most common subtype. Severity can range from mild and unobtrusive to severe and can result in incapacity to work, travel, or interact with others.

See Medscape's Anxiety Disorders Resource Center.

Pathophysiology

Several theories are postulated for the biological etiology of phobic disorders, most focusing on the dysregulation of endogenous biogenic amines. Sympathetic nervous system activation is common in phobic disorders, resulting in elevations in heart rate and blood pressure, as well as symptoms such as tremor, palpitations, sweating, dyspnea, dizziness, and/or paresthesias.²

Psychological theories range from explaining anxiety as a displacement of an intrapsychic conflict (psychodynamic models) to conditioning (learned) paradigms (the cognitive-behavior models). Many of these theories capture portions of the disorder.

A psychoanalyst would likely conceptualize social anxiety as a symptom of a deeper conflict—for instance, low self-esteem or unresolved conflicts with internal objects. The treatment uses exploration with the goal of understanding the underlying conflict. A behaviorist would see phobia as an learned, conditioned response resulting from a past association with a situation with negative emotional valence at the time of association (eg, social situations are avoided because intense anxiety was originally experienced in that setting). Even if no danger is posed in most social encounters, an avoidance response has been linked to these situations. Treatment from this perspective aims to weaken and eventually separate the specific response from the stimulus.

Genetic factors seem to play a role in both social phobia and specific phobia. Based on family and twin studies, the risk for specific phobias and social anxiety appears to be moderately heritable.^{3, 4}

Frequency

United States

The National Comorbidity Survey reported the following lifetime (and 30-day) prevalence estimates: 6.7% (and 2.3%) for agoraphobia, 11.3% (and 5.5%) for simple phobia, and 13.3% (and 4.5%) for social phobia.^{5, 6} 

Social phobia is the most common anxiety disorder; it has an early age of onset—by age 11 years in about 50% and by age 20 years in about 80% of individuals that have the diagnosis—and it is a risk factor for subsequent depressive illness and substance abuse.⁷

International

European data generally are similar to those of the United States.

Mortality/Morbidity

Considerable evidence shows that social anxiety results in significant functional impairment and decreased quality of life.^{8, 9} Despite evidence of impairment, only a minority of individuals with simple phobia ever seek professional treatment.

Phobias are highly comorbid. Most comorbid simple and social phobias are temporally primary, while most comorbid agoraphobia is temporally secondary. Comorbid phobias are generally more severe than pure phobias. Social phobia is also frequently comorbid with major depressive disorder and atypical depression, which results in increased disability.^{9, 10}

Controversy exists whether anxiety disorders in general and phobias in particular are independently associated with suicidal ideation and suicide attempts (ie, after adjusting for comorbid mental disorders). New evidence suggests that even after adjusting for socio-demographic factors and other mental disorders, baseline presence of any anxiety disorder, including agoraphobia, social phobia, and specific phobias, is significantly associated with suicidal ideation and suicide attempts. Additionally, the presence of any anxiety disorder, phobias included, in combination with a mood disorder appears to increase likelihood of suicide attempts compared with a mood disorder alone.¹¹

Significant morbidity is possible in terms of work and relationships, especially in social phobia and agoraphobia.

Race

The occurrence of phobias appears equally distributed among races.

Sex

• Specific phobia has a female-to-male ratio of 2:1.
• Social phobia is more common in women, but more men seek treatment due to career issues.
• Agoraphobia has a female-to-male ratio of 2-3:1.

Age

Most anxiety disorders appear earlier in life. Animal phobias are most common at the elementary school level. Earlier median ages at illness onset are reported for simple phobia (15 y) and social phobia (16 y) than for agoraphobia (29 y).⁵

• Specific phobia: Age of onset depends on the phobia. In general, specific phobia appears earlier than social phobia or agoraphobia. Examples include the following:
• • Animal phobia appears at a mean age of 7 years.
  • Blood phobia appears at a mean age of 9 years.
  • Dental phobia appears at a mean age of 12 years.
  • Claustrophobia appears at a mean age of 20 years.
  • Most simple phobias develop during childhood and eventually disappear. Those that persist into adulthood rarely go away without treatment.
• Social phobia: Most social phobias begin before age 20 years.
• Agoraphobia: Agoraphobia usually begins in late adolescence to early adulthood.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Social phobia: Ask the patient about any difficulties in social situations, such as speaking in public, eating in a restaurant, or using public washrooms. Fear of scrutiny by others or of being embarrassed or humiliated is described commonly by people with social phobia.
• Agoraphobia: Inquire about any intense anxiety reactions that occur when the patient is exposed to specific situations such as heights, animals, small spaces, or storms. Other areas of inquiry should include fear of being trapped without escape (eg, being outside the home and alone; in a crowd of unfamiliar people; on a bridge, in a tunnel, in a moving vehicle).
• Specific phobias: If specific phobias are suspected, specific questions need to be asked about irrational and out of proportion fear to specific situations (eg, animals, insects, blood, needles, flying, heights).
• Phobias can be disabling and cause severe emotional distress, leading to other anxiety disorders, depression, suicidal ideation, and substance-related disorders, especially alcohol abuse or dependence. The physician must inquire about these areas as well.

Physical

Anxiety is the most common feature in phobic disorders. Manifestations include the following (which should be asked about and examined):

• Elevated heart rate
• Elevated blood pressure
• Tremor
• Palpitations
• Diarrhea
• Sweating
• Dyspnea
• Paresthesias
• Dizziness

Causes

• Social phobia can be initiated by traumatic social experience (eg, embarrassment) or by social skills deficits that produce recurring negative experiences. A hypersensitivity to rejection, perhaps related to serotonergic or dopaminergic dysfunction, is present. Current thought is that social phobia appears to be an interaction between biological and genetic factors and environmental events.
• Specific phobia can be acquired by conditioning, modeling, traumatic experience, or even may have a genetic component (eg, blood-injury phobia).
• Agoraphobia may be the result of repeat, unexpected panic attacks, which, in turn, may be linked to cognitive distortions, conditioned responses, and/or abnormalities in noradrenergic, serotonergic, or gamma-aminobutyric acid (GABA)–related neurotransmission.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Depersonalization disorder
Seizure
Vertigo
Vestibular dysfunction

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

To rule out anxiety secondary to medical conditions, the following tests are helpful:

• Thyroid function tests - Hypothyroidism or hyperthyroidism 
• Fasting glucose - Hypoglycemia
• Calcium - Hyperparathyroidism
• Electrocardiogram and cardiac enzyme tests - Myocardial infarct
• 24-hour urine for 5-hydroxyindoleacetic acid (5-HIAA) - Pheochromocytoma

A drug screen is helpful to rule out substance-induced anxiety. 

Imaging Studies

• Imaging studies are limited to presentations where medical illness, such as a seizure disorder, is suspected.
• • Head CT scan - Suspected intracranial abnormality
  • MRI - Intracranial abnormality
  • Echocardiogram - Mitral valve prolapse

Other Tests

• ECG may be used to exclude arrhythmia.
• EEG may be used to exclude seizure disorder because these conditions may mimic anxiety.
• Provocation studies with carbon dioxide, sodium lactate, or yohimbine, as well as positron emission tomography (PET) studies, are reserved for research purposes at this point.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

Treatment usually consists of a combination of pharmacotherapy (see Medication) and/or psychotherapy.¹² Behavioral therapy and cognitive behavioral therapy (CBT) have demonstrated efficacy through controlled studies.¹³ Psychodynamic therapy (or insight-oriented therapy) is rarely indicated as an exclusive treatment for phobias and is now mostly used for cases of phobic disorders that overlap personality disorders. Deciding which treatment or combination of treatments to prescribe depends on a careful interview and assessment of the patient's goals and level of pathology.

Patient prognosis is determined by several factors, including:

• Severity of diagnosis
• Level of functioning prior to onset of symptoms
• Degree of motivation for treatment
• Level of support (eg, family, friends, work, school)
• Ability to comply with medication and/or psychotherapeutic regimen

Consultations

Internal medicine or neurologic consultation may be helpful to sort through the nonpsychiatric differential, especially if rare disorders, such as pheochromocytoma, are suspected.

Diet

Inquire about the amount of caffeine intake (including coffee, caffeinated teas, or sodas). Considering the overall noradrenergic hyperdrive of this group of patients, even moderate amounts of coffee might exacerbate the anxiety response and symptoms. In a small, double-blind, placebo-controlled study, a tryptophan-rich diet was shown to have a positive effect on social anxiety.¹⁴ Dietary restrictions (a tyramine-free diet) are necessary for patients taking monoamine oxidase inhibitors (MAOIs).

Activity

Activity should not be restricted. In fact, patients should be encouraged to confront anxiety-producing stimuli in the context of a behavior therapy treatment plan.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Specific phobia

Specific phobias respond best to cognitive behavioral therapy (CBT) and exposure therapy. Gradual desensitization is the most commonly used treatment. Other treatments include cognitive approaches, relaxation, and breathing control techniques. To date, no controlled studies demonstrate the efficacy of psychopharmacological intervention for specific phobias.

Agoraphobia

Agoraphobia, specifically the panic symptoms, most often responds to treatment with a selective serotonin reuptake inhibitor (SSRI).^{15, 16, 17} Treatment should be started at a low dose then titrated to the minimum effective dose for controlling the patient's panic. Benzodiazepines can be used either as an adjunct or as primary treatment; however, benzodiazepines are usually not chosen as a first-line treatment because of the potential for abuse.¹⁸ If the patient has frequent panic attacks and no history of substance abuse, a benzodiazepine can be considered until the SSRI takes effect. Long-acting benzodiazepines (eg, diazepam, clonazepam) prescribed on a standing rather than as-needed basis are preferred due to a lower addictive potential; dose can be increased every 2-3 days until panic symptoms are controlled or the maximum dose is reached.

Consider using the short-acting alprazolam for short-term use to control acute symptoms of panic. If response is minimal or nonexistent after 6 weeks, the SSRI dose can be further increased every 2 weeks until response or maximal dose is reached. Partial or no response at the highest SSRI dose warrants consideration of the following alternatives: change to a different SSRI, change to a different class (venlafaxine, duloxetine), tricyclic/tetracyclic antidepressants (TCAs) or MAOIs (both TCAs and MAOIs have demonstrated efficacy in controlled trials for agoraphobia).

For a patient with good response, treatment should be continued for 9-12 months before considering slowly tapering the medications. With symptom reoccurrence following taper, treatment should be resumed and continued indefinitely.

Social anxiety disorder (social phobia)

Both pharmacotherapy and psychotherapy are useful in treating social anxiety disorder (SAD). Social phobia typically responds to either an SSRI or an MAOI.^{19, 20, 21}

Initiate treatment with an SSRI and titrate to the minimum effective dose. SSRIs approved for SAD include paroxetine²² (including SR form) and sertraline, but other SSRIs have also been shown to be effective (eg, fluvoxamine²³). The SSRI dose can be increased if response is partial or nonexistent at 6 weeks—doses can be increased every 2 weeks until maximum dose is reached. Failing this, patients sometimes respond to high-potency benzodiazepines. Long-term treatment data from clinical studies of clonazepam are limited but support the drug's efficacy.²⁰ Beta-blockers, clonidine, and buspirone are usually not helpful for long-term treatment, although beta-blockers (eg, atenolol, nadolol, propranolol) may be useful for the circumscribed treatment of situational/performance anxiety on an as-needed basis.

Consider tapering medications slowly after 6-12 months of full response. If symptoms reoccur following taper, restart therapy and continue indefinitely.²⁰

Drug Category: 5-HT1 agonist

These agents may be used to treat anxiety.

Drug Category: Benzodiazepines

This category of medication should not, in general, be prescribed to patients with a history of alcohol/drug abuse or emotional dependence. Some psychiatrists feel that the longer-acting benzodiazepines (eg, diazepam, clonazepam) have advantages such as less frequent dosing and more consistent levels throughout the day. Slowly taper benzodiazepines (usually after 6 mo) to avoid withdrawal and precipitating panic.

Drug Category: Antihypertensive agents

These agents are useful for the circumscribed treatment of situational/performance anxiety on an as needed basis.

Drug Category: Antidepressants

Serotonin reuptake inhibitors may require 2-6 weeks of daily use to become effective, usually not without side effects appearing first. Shown to be effective in controlled clinical trials. As a class, it tends to have the fewest adverse effects. However, these agents can produce drug-drug interactions through their inhibition of cytochrome P450 enzymes and by displacement of other drugs from protein binding sites.

SSRIs are greatly preferred over the other classes of antidepressants. Because the adverse effect profile of SSRIs is less prominent, improved compliance is promoted. SSRIs do not have the cardiac arrhythmia risk associated with tricyclic antidepressants. Arrhythmia risk is especially pertinent in overdose, and suicide risk must always be considered, particularly when treating a child or adolescent with mood disorder.

Physicians are advised to be aware of the following information and use appropriate caution when considering treatment with SSRIs in the pediatric population.

In December 2003, the UK Medicines and Healthcare Products Regulatory Agency (MHRA) issued an advisory that most SSRIs are not suitable for use by persons younger than 18 years for treatment of "depressive illness." After review, this agency decided that the risks to pediatric patients outweigh the benefits of treatment with SSRIs, except fluoxetine (Prozac), which appears to have a positive risk-benefit ratio in the treatment of depressive illness in patients younger than 18 years.

In October 2003, the US Food and Drug Administration (FDA) issued a public health advisory regarding reports of suicidality in pediatric patients being treated with antidepressant medications for major depressive disorder. This advisory reported suicidality (both ideation and attempts) in clinical trials of various antidepressant drugs in pediatric patients. The FDA has asked that additional studies be performed because suicidality occurred in both treated and untreated patients with major depression and thus could not be definitively linked to drug treatment.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Indicated only for severe cases presenting with acute suicidal ideation and/or attempt. Also, inpatient treatment including detox and/or rehab may be recommended for treatment of secondary drug and/or alcohol abuse or dependence.

Further Outpatient Care

• Outpatient follow-up is usually needed through resolution of symptoms. After symptoms are resolved, physician can (1) attempt a taper of medication and therapy and (2) monitor for relapse.

In/Out Patient Meds

• Continue medication regimen for at least 6-12 months.
• If symptoms have resolved and the patient is not experiencing excessive stress, the physician can taper the patient off medication gradually.
• Psychotherapy usually helps make the transition off medication more successful.

Transfer

• Physicians without expertise in conducting behavioral therapy may want to consult with a psychiatric center specializing in treatment of anxiety disorders for guidance on developing a treatment plan or for referral (for more difficult cases).

Deterrence/Prevention

• Overwhelming exposure in early childhood (eg, a frightening experience with an aggressive dog) may predispose the child to the development of phobic symptoms. Intervention (psychotherapy or medication) in the early stages of symptom development may be beneficial in preventing worsening of symptoms.

Complications

• Left untreated, social phobia or agoraphobia can result in tremendous morbidity. The patient becomes restricted to the most familiar surroundings (eg, house) or most trusted people (eg, family member, spouse). Therefore, the ability to work and relate to other people is significantly impaired. Significant risk of substance abuse exists with this degree of isolation.
• Patients with specific phobia may also be limited by having to avoid buildings (in the case of acrophobia), elevators (in the case of claustrophobia), or even their own lawn (eg, fear of snakes). Usually, less impairment is observed in specific phobia than in social phobia or agoraphobia.

Prognosis

• Most patients respond to treatment, with good resolution of symptoms.
• Patients with specific phobia often recover to the highest level of functioning, while agoraphobics or social phobics either may have residual symptoms or run a greater risk of relapse even after successful treatment.
• Social phobics with extensive deficits in social skills may not respond well to treatment.

Patient Education

• The treating physician should begin a process of education, not only for the patient but also for family and friends who may be confused about the diagnosis and the need for treatment. Abilities that most people take for granted, such as socializing at gatherings or riding in a small elevator, may seem commonplace, but patients who experience phobias have tremendous difficulty in these areas and can be helped significantly by a caring support system. Family and friends can encourage the patient to confront fears, help the patient when necessary (with medication compliance or confronting fearful situations), and can also learn when to stay out of the way and allow the patient to venture forth on his own.
• Numerous books and self-help groups are available. In addition, patient advocacy groups exist nationwide to provide patients with information, presentations, and conferences. The following Web sites are helpful:
• • Social Phobia/Social Anxiety Association
  • American Psychiatric Association
  • Anxiety Disorders Association of America
  • MedlinePlus, Phobias
  • MayoClinic.com, Phobias
  • FDA, Fighting Phobias, The Things That Go Bump in the Mind
• For excellent patient education resources, visit eMedicine's Anxiety Center. Also, see eMedicine's patient education articles Anxiety, Panic Attacks, and Hyperventilation.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Patients with social phobia have substantial associated morbidity such as increased suicidal ideation, social isolation, and substance abuse.
• Patients with severe agoraphobia may be housebound and therefore unable to seek out medical attention when needed. Patients with concomitant panic attacks are at higher risk for substance abuse and suicide.
• Many anxiety attack symptoms resemble those found in life-threatening medical disorders, such as myocardial infarction, which must be ruled out first.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

1. American Psychiatric Association. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Washington, DC: American Psychiatric Association Press; 2000.
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10. Matza LS, Revicki DA, Davidson JR, Stewart JW. Depression with atypical features in the national comorbidity survey. Arch Gen Psychiatry. 2003;60:817–826. [Full Text].
11. Sareen J, Cox BJ, Afifi TO, de Graaf R, Asmundson GJ, ten Have M, et al. Anxiety disorders and risk for suicidal ideation and suicide attempts: a population-based longitudinal study of adults. Arch Gen Psychiatry. 62(11);2005 Nov:1249-57. [Medline]. [Full Text].
12. de Beurs E, van Balkom AJ, Van Dyck R. Long-term outcome of pharmacological and psychological treatment for panic disorder with agoraphobia: a 2-year naturalistic follow-up. Acta Psychiatr Scand. Jan 1999;99(1):59-67. [Medline].
13. Shear MK, Beidel DC. Psychotherapy in the overall management strategy for social anxiety disorder. J Clin Psychiatry. 1998;59 Suppl 17:39-46. [Medline].
14. Hudson C, Hudson S, MacKenzie J. Protein-source tryptophan as an efficacious treatment for social anxiety disorder: a pilot study. Can J Physiol Pharmacol. Sep 2007;85(9):928-32. [Medline].
15. American Psychiatric Association: Practice Guideline for the Treatment of Patients With Panic Disorder. Am J Psychiatry. May suppl, 1998;155.
16. Pohl RB, Wolkow RM, Clary CM. Sertraline in the treatment of panic disorder: a double-blind multicenter trial. Am J Psychiatry. Sep 1998;155(9):1189-95. [Medline]. [Full Text].
17. Michelson D, Lydiard RB, Pollack MH. Outcome assessment and clinical improvement in panic disorder: evidence from a randomized controlled trial of fluoxetine and placebo. The Fluoxetine Panic Disorder Study Group. Am J Psychiatry. Nov 1998;155(11):1570-7. [Medline]. [Full Text].
18. Uhlenhuth EH, Balter MB, Ban TA, Yang K. International study of expert judgment on therapeutic use of benzodiazepines and other psychotherapeutic medications: VI. T