The Presentation and Treatment of Specific Phobia

Psychiatrist, Private Practice, Staff Psychiatrist, University of California Irvine Student Health Center

This interview was conducted on January 10, 2007 by Peter Cook.

Introduction

Specific phobia—a heterogeneous group comprising animal, environmental, situational, and blood-injury phobias—is strikingly prevalent in the US. 12.5% of the population is estimated to suffer from one or more phobias. Precise data on the prevalence of particular phobias is not currently available, but women are twice as likely to be affected as men,  children are more prone than adults, and the irrational fear of animals are the most common, says Dr. Yujuan Choy. A Cornell-trained psychiatrist whose area of expertise is the integration of medication and CBT in the treatment of anxiety disorders, Dr. Choy has conducted clinical research on phobias, and is the lead author of a recently published, comprehensive review on the subject (http://www.ncbi.nlm.nih.gov/entrez/ query.fcgi?CMD=search&DB=pubmed). The irrational fear of heights and situational fears, such as fear of closed spaces or fear of flying, are most common after fear of animals, Dr. Choy says.  Blood-injury fears are a little less common, and include fear of medical procedures, injections, and dental phobia.

Presentation

“Phobias most commonly start in childhood,” Dr. Choy says, “and many kids simply outgrow them. One consequence of this, and part of the motivation of our recent review, has been less attention given to treating phobias in adults.” Phobias are still common in adults, but the majority of patients will not present to a psychiatrist complaining of phobia. “Phobias frequently present with social anxiety disorder, agoraphobia, and panic disorder, although the most common comorbidity is another phobia, so a careful history will often uncover one,” Dr. Choy explains. “Most psychiatrists will refer patients to clinical psychologists for treatment of phobia, either because the psychiatrists do not practice CBT, or because treatment is too expensive or time-intensive for most patients to pursue with a psychiatrist.” Some patients will, however, seek benzodiazepine prescriptions from their psychiatrists for fear of flying.

Dr. Choy notes that it is important to assess the focus of fear during the evaluation of specific phobia. In specific phobia, the focus of fear is predominantly an anticipated danger or harm due to the phobic stimulus, distinguishing it from other anxiety disorders like panic disorder in which the fear is of having another panic attack or of perceived consequences of a panic attack.  For example, a patient with flying phobia or panic disorder can both present with panic attacks on an airplane, but the flying phobic is afraid of the plane crashing whereas the panic patient is fearful of the panic attack itself. 

Pathophysiology   &nb sp; 

There is limited knowledge about the biological underpinnings of specific phobia, but people who have a family member with phobia are far more likely to have a phobia of their own, so genetics very likely play a role. While the majority of phobias present with a sympathetic nervous response (elevated heart rate and blood pressure) on exposure to a phobic stimulus, patients with blood-injury phobia most often present with an initial sympathetic activation followed by a strong parasympathetic response (often fainting).

Brain-imaging indicates that the amygdala, involved in general fear responses, is involved in specific phobia as well. However, whether specific phobia involves a particular type of malfunction in the fear circuit is not yet clear.

Treatment

“Most treatments for specific phobias involve exposure therapy,” Dr. Choy says. “Exposure therapy is a form of behavioral treatment in which the clinician presents the patient with the fear stimulus in a controlled environment.” The most common and effective exposure therapy is in vivo treatment, in which the patient is presented with the actual fear stimulus (eg, if the patient is afraid of snakes, in vivo therapy would involve the patient coming into some kind of controlled contact with actual snakes).

Two other kinds of exposure therapy are virtual therapy and imaginal therapy, in which the patient is presented with a virtual simulation of the fear stimulus or is guided to visualize the fear stimulus respectively. Virtual therapy is particularly favored for treatment of flying and height phobias, as it is far cheaper and more practical and possibly better tolerated than traditional exposure treatment for these phobias. Clinicians begin by exposing a patient to less-anxiety provoking stimuli (eg, if they are afraid of snakes, perhaps a picture of a snake, or a small snake in a box on the other side of the room), and gradually transition the patient to increasingly direct exposure (eg, touching a larger snake).

“One of the most important aspects to exposure therapy is establishing trust with the patient,” Dr. Choy says. “If someone is very afraid of something, he or she will not want to confront it. The patient must trust that the clinician has the patient’s safety in mind, and will not expose the patient to any real harm. Further, clinicians should hold off on introducing a more fear-evoking stimulus until the patient’s anxiety has been significantly reduced with the less extreme stimuli. For example, if the patient still has a panic attack when viewing a video of a snake, he or she isn’t ready to be brought into contact with a real, live snake.”

Avoidance maintains fear, and as patients are brought to face their fears, they naturally habituate over time. “There’s also a cognitive aspect to exposure therapy,” Dr. Choy says. “Patients learn that when they don’t avoid the fear stimulus their fear lessens. Through exposure they learn that their fear is irrational, and this may aid in recovery.”

There has been little research on cognitive therapy as front-line treatment for phobia, but there is indication that it may be helpful with claustrophobia and dental phobia. Many clinicians combine cognitive and exposure therapies, but outside of claustrophobia there is no clear evidence of increased treatment efficacy with addition of a cognitive component.

Of note, just as presentation of blood- injury phobia differs, frontline treatment differs as well. The treatment of choice is applied muscle tension, which involves tensing muscles during exposure to the fear stimulus—this very quickly and effectively counters the parasympathetic response, preventing the blood pressure drop, and helping to avoid fainting.

There is little data on drug treatment for phobia, but benzodiazepines are commonly prescribed to patients with situation-specific anxiety attacks, and new evidence suggests that d- cycloserine significantly reduces the length of treatment when used as an adjunct to exposure therapy.

Conclusion

In vivo treatment is successful in up to 90% of treatment completers. However, Dr. Choy cautions, phobia patients have high rates of dropout, and relapse after successful treatment may also be a problem. “People dropping out are often the people who most need treatment, so it’s very important to make sure patients are comfortable with the treatment.” For example, someone with height phobia may refuse to begin exposure therapy if they know they’re going to start out on the top of a tall building, but they may agree to begin treatment if it begins with a virtual height exposure. “Treatment of phobia often involves exposing patients to fear-inducing stimuli,” Dr. Choy says. “Successful treatment requires trust, and it requires a real collaboration between clinician and patient, from start to finish.”

Disclosure: Dr. Choy reports no affiliations with or financial interests in any organization that may pose a conflict of interest.