232 Specific Phobia (300.29)

DSM-IV-TR Criteria

• A. Marked and persistent fear that is excessive or unreasonable, cued by the presence or anticipation of a specific object or situation (e.g., heights, blood, injections, animals). Specific anxiety and fear elicited by an object or situation and resulting in avoidance behaviors.
• B. Exposure to the phobic stimulus almost invariably provokes an immediate anxiety response, which may take the form of a situationally bound or situationally predisposed panic attack. Children can show affects and characteristics when it comes to specific phobias. Children can show anxiety by crying, throwing tantrums, experiencing freezing or clinging to the parent that they have the most connection to.
• C. The person recognizes that the fear is excessive or unreasonable. NOTE: In children, this feature may be absent.
• D. The phobic situation(s) is(are) avoided, or else endured with intense anxiety or distress.
• E. The avoidance, anxious anticipation, or distress in the feared situation(s) interferes significantly with the person’s normal routine, occupational (or academic) functioning, social activities or relationships, or there is marked distress about having the phobia.
• F. In individuals under age 18 years, the duration is at least 6 months.
• G. The phobic avoidance associated with the specific object or situation are not better accounted for by another mental disorder, such as obsessive-compulsive disorder (e.g., fear of dirt on someone with an obsession about contamination), post-traumatic stress disorder (e.g., avoidance of stimuli associated with a severe stressor), separation anxiety disorder (e.g., avoidance of school), social phobia (e.g., avoidance of social situations because of fear of embarrassment), panic disorder with agoraphobia, or panic disorder without agoraphobia.

The DSM-IV-TR categorizes five general types of SP:

1. Animal Type: These include fears of animals such as dogs, snakes, cats, bears, etc.
2. Natural Environment Type: These include fears of heights, storms, and being near a water source such as a river or lake.
3. Blood-Injection-Injury (B-I-I) Type: These include fears of seeing blood; receiving a blood test or injection; for the more serious types of this phobia, seeing an injection on television or talking about the act.
4. Situational Type: These include fears of situations such as driving, flying, elevators, and enclosed places.
5. Other Type: These include other specific fears, including fear of choking or vomiting after eating certain foods, fear of balloons breaking or guns going off, fear of clowns or midgets.

There is controversy over these divisions, however. Some research has shown that SP instead may be better divided into three primary clusters of animal, B-I-I, and a combined situational/natural environment type, while other analyses have found only two clusters: B-I-I and all others. Still other researchers contend that dividing the categories based on the type of emotion elicited by the phobic object, fear or disgust, is most accurate and clinically useful. Much more research is needed in this area to clarify this issue.

Associated Features

People with SP will often remember fearful experiences they encountered in a drastically exaggerated manner. For example, a person with a fear of dogs may remember a dog they once encountered as being larger and faster than it actually was, or baring its teeth viciously when it was only panting with an open mouth. They will often go to great lengths to avoid an encounter with the phobic object, affecting one’s work, family, and social life. For instance, a job may require a person to fly for a business meeting, but a fear of flying could keep them from completing this job task and result in the loss of that job. Exposure to feared stimuli often causes significant physiological responses, such as dizziness, shortness of breath, increased heart rate, and even fainting.

Over 75% of individuals who are diagnosed with SP actually have multiple phobias, with over 50% reporting three or more. In animal and height phobias, there is a substantial comorbidity with major depressive disorder, but this relationship is not seen across the other types. Across all types, though, comorbid anxiety disorders are highly common, but not as high as in other types of anxiety disorders.

With the B-I-I type, a strong vasovagal fainting response is common, characterized by an acceleration of heart rate and elevation in blood pressure followed by rapid deceleration of heart rate and drop in blood pressure and not infrequent fainting. This is in direct contrast to the acceleration in heart rate and elevation in blood pressure seen in the other specific phobias. It has been hypothesized that these differences are a biological protection mechanism, as one would want the sympathetic nervous system to be highly activated for most phobic objects, in order to enable “fight or flight.” In B-I-I, for instance if you were seriously injured and bleeding, sympathetic nervous system activation would cause the heart to beat furiously, pumping blood out of the wound and putting one at greater risk of death.

As illustrated in some of the examples above, SP can have quite a negative impact on a person’s functioning. Both adults and youth with clinical-level phobias shower a lower overall quality of life (QoL) than those without SP. In adults, functional impairment in education and employment has been observed, as well as more work loss days and poorer physical and mental QoL.

Child vs. Adult Presentation

Children will often express anxiety associated with this phobias by freezing, crying, throwing tantrums, or by refusing to let go of a person they trust to protect them. Children seem to display a higher degree of response to perceived threats of their phobias than adults. However, the physical anticipatory response is higher in adults. Adults and teenagers are usually aware that their phobia is unreasonable, although younger children often will not be. Children with SP are more likely to show distorted thoughts and memories concerning past experiences with the feared stimuli than are adults, but whether this is a result of the fear or caused the fear in the first place is unknown.

Gender and Cultural Differences in Presentation

Females in general have about a 2:1 ratio to males for having SP, with between 21.2‐26.5% of women and 10.9‐12.4% of men meeting criteria. Animal, situational, and storm or water phobias are overwhelmingly female, while heights (60% female) and B‐I‐I (35‐65% female) more evenly distributed. There appear to be few differences in type prevalence across SES, family structure, or age, though.

There is some research on cultural differences, but not much. For example, here in the U.S., African‐Americans endorse SP at three times the Caucasian rate, as well as endorsing more animal phobias but fewer B‐I‐I phobias. Interestingly, persons of Asian and Hispanic heritage show lower rates than Caucasians. Around the world, the overall reported prevalence rates in Puerto Rico, Germany, Switzerland and New Zealand are extremely low. One thing to note is that a fear that is commonly present in a culture, such as a fear of magic or spirits, should not be considered a SP unless it is in excess for that particular culture.

Epidemiology

Rates of SP in the general population are very high, with a lifetime prevalence rate of 12.5% and 12-month rate of 9.1%. A natural decline in SP rates across the lifespan is seen, with rates in 18-29 year olds almost double that of persons over 60 (10.3% vs. 5.6% over a 12-month period). The rates for types of phobias vary dramatically, with natural environment the most occurring (8.9-11.6%), followed by situational (5.2‐8.4%), animal (3.3‐7%), and B‐I‐I (3‐4.5%).

The onset age depends upon the type of phobia. Generally, animal (6.3‐9.2 years), natural environment (6.5‐13.6 years), and B-I-I (5.5‐9.4 years) types develop in early childhood. Fear of heights and situational specific phobias (such as claustrophobia) typically develop during the late teenage years and early third decade of life (13.4‐21.8 years).

Given these high rates, and the fact that treatment for SP works remarkably well (see below), it is surprising how few persons actually present to treatment for phobias. For example, in a college sample, 34% of students reported being “significantly” or “severely” afraid of spiders, but less than 1 in 5 of them was interested in seeking treatment. This is particularly sad given the average age of onset for most phobias is prior to adolescence, which means people are spending decades of their life being terrified by something that could be resolved in a short time.

Etiology

There are two possible frameworks to view the development of SP: associative and nonassociative. The associative model of SP developed from animal models of fear, with some of the earliest work being done by John B. Watson using only classical conditioning (the famous – or infamous – “Little Albert” studies). As knowledge about operant conditioning grew, however, Mowrer’s two‐factor theory of avoidance learning became highly influential. In this theory, fears develop initially via classical conditioning and are then maintained via the operant conditioning process of negative reinforcement. For example, a girl gets attacked by a dog, classically associating the dog with fear; she then goes out of her way to avoid dogs, such as crossing the street to avoid encounter one, not going into pet stores, or declining invitations to parties where the host has a dog, negatively reinforcing that avoidance. Vicarious conditioning can also play an important role in associative learning, via modeling (a child sees a parent display fear or disgust to stimuli, and then patterns his behavior after that), information transmission (hearing about how dangerous it is to fly due to terrorists), and visual observation of fear (watching someone else encounter a stimuli and display phobic reactions). The impact of these types of associative learning, however, appear to be strongly mediated by nonassociative factors, such as preparedness and innate fears.

Evolutionary preparedness is a nonassociative theory that we as a species may be genetically primed to fear certain stimuli, thanks to our evolutionary history. This would include commonly phobic objects such as snakes and reptiles, spiders, the dark, heights, and closed spaces. The theory is that, due to the inherent dangerousness of such things throughout the history of our species, those individuals with a natural tendency to avoid such things were more likely to survive and reproduce, passing on the genes related to such a behavioral expression. It would also help to explain why things that are actually more dangerous, such as guns and cars, but have been around a relatively short period of time are not seen in phobic individuals nearly as often. This is not to say, though, that people are born afraid of certain stimuli. Instead, we slowly acquire the competencies needed to deal with both fear predispositions and actual fears, with phobias being those predispositions or fears that are a) resistant to extinction or habituation and b) acquired through associative processes. As such, one’s environment can work toward eliminating biologically relevant fears via the same processes that are at work in building them. As such, the reality seems to be that it is not whether a given fear is associative or nonassociative, but instead how much learning is needed to evoke that particular fear.

Empirically Supported Treatments

Unlike the other anxiety disorders, where there are both supported psychological and pharmacological therapies, the treatment of specific phobias is done only with psychotherapy. The gold‐standard treatment for phobias is exposure with response prevention, specifically using Öst’s “One Session Treatment” protocol. There are two phases in this therapy: assessment and treatment. First, the clinician conducts a diagnostic assessment using an evidence‐based, multi‐method and multi-informant approach. This would include a structured or semi-structured interview such as the Anxiety Disorder Interview Schedule (ADIS‐IV), self‐report, and behavioral avoidance tasks. Afterwards, a functional assessment follows to accomplish several goals. First, to determine any maintaining variables of the phobia that would impede treatment. Second, a fear hierarchy, which is a rank ordering of feared stimuli or situations from most to least fearful, is generated. Next, the hierarchy is used to catalog most severe and catastrophic cognitions associated with each stimuli or situation. The clinician also attempts, if possible, to determine the onset and course of the phobia. Finally, the assessment allows the clinician to build rapport and present the rationale for treatment.

During the treatment phase, the clinician primarily makes use of exposure with response prevention techniques, but also incorporates cognitive challenges, modeling, reinforcement, education, and skills training into therapy. Exposures are seen as a series of negotiated behavioral experiments based on the fear hierarchy constructed during the assessment phase. Starting near the bottom of the hierarchy, the patient gradually confronts more and more fear-provoking stimuli, guided by the therapist. Patients must show at least a 50% decrease in distress to each stimuli before moving on to the next one. Generally, the treatment phase will last around three hours, allowing for massed exposure to the fear stimuli. This is then followed by self- or parent-guided exposures for homework, which allows overlearning to occur and a complete extinction of the fear to happen. Success rates with this time of treatment are astounding, with effect sizes well over 1.0 and treatment gains maintained for years afterward.

Proposed DSM-5 Revisions

The proposed changes for SP are primarily wording changes, rather than substantive diagnostic changes. For example, the DSM-IV wording of “marked and persistent fear” is changed to “marked fear or anxiety.”

Key References

Coelho, C., & Purkis, H. (2009). The origins of specific phobias: Influential theories and current perspectives. Review of General Psychology, 13(4), 335‐348.

Davis, T., Ollendick, T. H., & Öst, L. (2009). Intensive treatment of specific phobias in children and adolescents. Cognitive and Behavioral Practice, 16(3), 294‐303.

LeBeau, R.T., Glenn, D., Liao, B., Wittchen, H‐U., Beesdo‐Baum, K. et al. (2010). Specific Phobia: A review of DSM‐IV Specific Phobia and preliminary recommendations for DSM‐V. Depression and Anxiety, 27, 148‐167.

Ollendick, T.H., Raishevich, N. Davis III, T.E., Sirbu, C. Ost, L‐G. (2010). Specific Phobia in youth: Phenomenology and psychological characteristics. Behavior Therapy, 41, 133‐141.

Seim, R. W., & Spates, C. (2010). The prevalence and comorbidity of specific phobias in college students and their interest in receiving treatment. Journal of College Student Psychotherapy, 24(1), 49‐58.