Phobic Disorders

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.

Collectively, phobic disorders are the most common forms of psychiatric illness, surpassing the rates of mood disorders and substance abuse. Severity can range from mild and unobtrusive to severe and can result in incapacity to work, travel, or interact with others.

Treatment of phobic disorders usually consists of pharmacotherapy, psychotherapy, or some combination thereof. As a rule, a selected medication regimen should be continued for at least 6-12 months. If the symptoms have resolved and the patient is not experiencing excessive stress, the physician can gradually taper the patient off the medication. Psychotherapy usually helps make the transition away from medication more successful.

Diagnostic criteria (DSM-5)

According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), phobic disorders are no longer a distinct group of anxiety disorders; ^[1] nonetheless, they may still constitute a useful conceptual category. The 3 diagnoses that may be thought of as belonging to this category are as follows:

• Social anxiety disorder (social phobia) - A strong, persisting fear of an interpersonal situation in which embarrassment can occur

• Specific phobia - An overwhelming, persisting fear of an object or situation; it differs from other anxiety disorders in that the fear and anxiety is induced by the presence of the phobic situation or object

• Agoraphobia - The fear of being alone in public places, particularly places from which a rapid exit would be difficult or help might not be available in the course of a panic attack or other embarrassing symptoms

Social anxiety disorder (social phobia)

The specific DSM-5 criteria for social anxiety disorder (social phobia) are as follows ^[1] :

• Marked fear or anxiety about 1 or more social situations in which the individual might be scrutinized by others, such as social interactions (eg, having a conversation or meeting unfamiliar people), being observed (eg, eating or drinking), and performing in front of others (eg, giving a speech); in children, the anxiety may occur in peer settings and not just during interactions with adults

• The individual fears acting in a way or showing anxiety symptoms that will be negatively evaluated (eg, will be humiliating or embarrassing, will lead to rejection, or will offend others)

• The social situation almost always provokes immediate fear or anxiety; in children, anxiety may be expressed by crying, tantrums, freezing, clinging shrinking, or failing to speak in social situations

• The social situations are actively avoided or endured with intense fear or anxiety

• The fear or anxiety is out of proportion to the actual threat posed by the social situation and to the sociocultural context

• The fear, anxiety, or avoidance persists, typically for 6 months or longer

• The fear, anxiety or avoidance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning

• The fear, anxiety or avoidance cannot be attributed to the physiologic effects of a substance (eg, a drug of abuse or medication) or another medical condition

• The fear, anxiety or avoidance cannot be better explained by the symptoms of another mental disorder (eg, panic disorder, body dysmorphic disorder, or autism spectrum disorder)

• If another medical condition (eg, Parkinson disease, obesity, or disfigurement caused by a burn or injury) is present, the fear, anxiety, or avoidance is clearly unrelated or is excessive

Performance-only subtype is specified when fear is restricted to speaking or performing in public. Individuals with performance-only social phobia do not fear or avoid nonperformance in generic social situations; their phobic reaction is typically restricted to professional performance (eg, musicians, dancers, performers, or athletes or public speaking).

Specific phobia

The specific DSM-5 criteria for specific phobia are as follows ^[1] :

• Marked fear or anxiety about a specific object or situation (eg, flying, heights, animals, receiving an injection, or seeing blood); in children, this fear or anxiety may be expressed by crying, tantrums, freezing or clinging

• The phobic object or situation almost always provokes immediate fear or anxiety

• The phobic object or situation is actively avoided or endured with intense fear or anxiety

• The fear or anxiety is out of proportion to the actual danger posed by the specific object or situation and to the sociocultural context

• The fear, anxiety, or avoidance persists, typically for 6 months or longer

• The fear, anxiety or avoidance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning

• The disturbance cannot be better explained by the symptoms of another mental disorder, including fear, anxiety, and avoidance of situations associated with paniclike symptoms or other incapacitating symptoms (as in agoraphobia); objects or situations related to obsessions (as in obsessive-compulsive disorder [OCD]); reminders of traumatic events (as in posttraumatic stress disorder [PTSD]); separation from home or attachment figures (as in separation anxiety disorder); or social situations (as in social anxiety disorder)

The following specifiers are used, according to the phobic stimulus present ^[1] :

• Animal - Fear of dogs (cynophobia), cats (ailurophobia), bees (apiphobia), spiders (arachnophobia), snakes (ophidiophobia), or other animals

• Natural environment - Fear of heights (acrophobia), water (hydrophobia), or thunderstorms (astraphobia)

• Blood-injection-injury - Fear of needles or invasive medical procedures

• Situational - Fear of flying, elevators, or enclosed spaces

• Other - Fear of situations that may lead to choking or vomiting; in children, loud sounds or costumed characters

Many individuals have multiple specific phobias. The average individual with specific phobia fears 3 objects or situations, and approximately 75% of individuals with specific phobia fear more than 1 situation or object. In such instances, multiple specific phobia diagnoses, each with its own diagnostic code reflecting the phobic stimulus, should be applied.

Agoraphobia

The specific DSM-5 criteria for agoraphobia are as follows ^[1] :

• Marked fear or anxiety about at least 2 of the following 5 situations: (1) using public transportation (e.g. automobiles, buses, trains, ships, or planes), (2) being in open spaces (eg, parking lots, marketplaces, or bridges), (3) being in enclosed places (eg, shops, theaters, or cinemas), (4) standing in line or being in a crowd, and (5) being outside the home alone

• The individual avoids these situations because of thoughts that escape might be difficult or help unavailable if paniclike symptoms or other embarrassing symptoms (eg, fear of falling in the elderly or fear of incontinence) should develop

• The agoraphobic situations almost always provokes immediate fear or anxiety

• The agoraphobic situations are actively avoided, necessitate the presence of a companion, or are endured with intense fear or anxiety

• The fear or anxiety is out of proportion to the actual threat posed by the agoraphobic situation and to the sociocultural context

• The fear, anxiety, or avoidance persists, typically for 6 months or longer

• The fear, anxiety or avoidance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning

• If another medical condition (eg, inflammatory bowel disease or Parkinson disease) is present, the fear, anxiety, or avoidance is clearly excessive

• The fear, anxiety, or avoidance cannot be better explained by the symptoms of another mental disorder—for example, the symptoms are not confined to specific phobia, situational type; do not involve only social situations (as in social anxiety disorder); are not related exclusively to obsessions (as in OCD), perceived defects or flaws in physical appearance (as in body dysmorphic disorder), reminders of traumatic events (as in PTSD), or fear of separation (as in separation anxiety disorder)

Although agoraphobia may be associated with panic disorder, it is diagnosed irrespective of the presence of panic disorder. In cases where the presentation meets the criteria for both panic disorder and agoraphobia, both diagnoses should be applied.

Several biologic theories are postulated for the pathogenesis 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 paresthesias. ^[2]

Genetic factors seem to play a role in both social anxiety disorder (social phobia) and specific phobia. On the basis of family and twin studies, the risks for specific phobia and social anxiety disorder appear to be moderately heritable. ^{[3, 4, 5]}

Preliminary neuroimaging evidence indicates that while different patterns of brain activation might be associated with the different phobias, ^[6]  there is an overall increased activation in the prefrontal and orbitofrontal cortex, anterior cingulate cortex, insula, and amygdala in phobic patients exposed to phobia-related triggers compared with healthy controls. ^[7]

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

A behaviorist would see phobia as a learned, conditioned response resulting from a past association with a situation that had 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.

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.

Neurobiologic and psychological theories, as well as familial patterns, have contributed to understanding the underlying causes of phobic disorders.

Neurobiologic theories

Social anxiety disorder (social phobia)

Positron emission tomography (PET) has shown lower serotonin (5-HT) 1A binding in the amygdala and mesiofrontal areas, and negative correlations between cortisol plasma levels and 5-HT1A binding in the amygdala, hippocampus, and retrosplenial cortex have been reported in patients with social anxiety disorder. ^{[8, 9]}

A review of 48 neuroimaging articles involving social anxiety disorder concluded that increased activity in the limbic and paralimbic regions is the most consistent finding (across imaging techniques) in social anxiety disorder. ^[10]

Further, increased connectivity in the salience network, including the dorsal anterior cingulate cortex, anterior insula, and amygdala have been consistently associated with SAD. ^[11]

Specific phobia

Phobic reactions may result from activation of object recognition and emotional processing areas occurring in conjunction with inhibition of the prefrontal areas that are responsible for cognitive control over emotion-triggering. ^[12]

In a meta-analysis reviewing data from 13 studies including 327 subjects, there was increased activation in the left amygdala/globus pallidus, left insula, right thalamus (pulvinar), and cerebellum in response to phobic stimuli. Further, widespread deactivation of the right frontal cortex, limbic cortex, basal ganglia, and cerebellum, with increased activation detected in the thalamus, followed exposure-based therapy. ^[13] While these results suggest a common neuroanatomy for specific phobias, other data suggest partially distinct neurobiologic substrates for different types of phobias. 

Psychological theories

Social anxiety disorder can be initiated by traumatic social experience (eg, embarrassment) or by social-skills deficits that produce recurring negative experiences. Hypersensitivity to rejection, perhaps related to serotonergic or dopaminergic dysfunction, is present. It is theorized that social anxiety disorder represents an interaction between biologic and genetic factors and environmental events.

Specific phobia can be acquired through conditioning, modeling, or a traumatic experience; it may even have a genetic component (eg, blood-injury phobia).

Agoraphobia may be the result of repeated and unexpected panic attacks, which, in turn, may be linked to cognitive distortions, conditioned responses, or abnormalities in noradrenergic, serotonergic, or gamma-aminobutyric acid (GABA)–related neurotransmission.

Familial patterns

A familial pattern has been reported for both social anxiety disorder and specific phobia. Generalized social anxiety disorder further increases the risk of familial transmission. With respect to specific phobia, first-degree relatives appear to have an increased risk for the subtype of the phobia rather than for the specific trigger. For example, a given family may exhibit an increased rate of animal phobias rather than share a phobia of a specific animal. ^[1]

United States statistics

The 12-month prevalence rates for the United States are estimated as follows ^[14] :

• Social anxiety disorder (social phobia) - 7%

• Specific phobia - 7-9%

• Agoraphobia - 1.7%

International statistics

Social anxiety disorder appears to be less common in much of the world than it is in the United States, with 12-month prevalence estimates clustering in the range of 0.5-2.0%; median prevalence in Europe is 2.3%. Prevalence estimates for specific phobia in European countries are close to those in the United States (~6%) but are generally lower in Asian, African, and Latin American countries (2-4%). ^[15]

Age-related demographics

In the United States, social anxiety disorder tends to start early in life, with 75% of the patients experiencing its onset between ages 8 and 15 years and a median age at onset of 13 years. ^[16] The 12-month prevalence estimates for social anxiety disorder in children and adolescents are comparable to those in adults. ^[14] Prevalence decreases with advancing age ^[17] ; the 12-month prevalence for older adults is in approximately 7%. ^{[14, 18]}

In general, specific phobia appears earlier than either social anxiety disorder or agoraphobia does. Most such phobias develop during childhood and eventually disappear. The estimated prevalence of specific phobia is approximately 5% in younger children ^[19] and 16% in children aged 13-17 years. ^[14] The prevalence is lower (3-5%) in older individuals, possibly reflecting a decrease in severity to subclinical levels. ^[14]

The 12-month prevalence of agoraphobia in adolescents and adults is approximately 1.7%. ^{[14, 20]} Agoraphobia may occur in childhood, but the incidence peaks in late adolescence and early adulthood. ^[21] The 12-month prevalence in individuals older than 65 years is 0.4%. ^[22]

Sex-related demographics

The phobic disorders appear to have a higher incidence among women. Higher rates of social anxiety disorder are found in females in the general population (with female-to-male ratios ranging from 1.5:1 to 2.2:1), ^[23] and the sex difference in prevalence is more pronounced in adolescents and young adults. ^[24]

Females are more frequently affected by specific phobia than males, at a rate of approximately 2:1, though rates vary across different phobic stimuli. Animal, natural environment, and situational specific phobias are predominately experienced by females, whereas blood-injection-injury phobia is experienced equally by the 2 sexes. ^[6]

Agoraphobia has a female-to-male ratio of 2-3:1. ^[25]

Race-related demographics

The prevalence of social anxiety disorder in the United States is higher in American Indians and lower in persons of Asian, Latino, African American, and Afro-Caribbean descent as compared with non-Hispanic white individuals. Prevalence figures for specific phobia and agoraphobia appear not to vary substantially across cultural or racial groups. ^[15]

Most patients respond to treatment, with good resolution of symptoms. Patients with specific phobia often regain the highest level of functioning, whereas those with agoraphobia or social anxiety disorders may have residual symptoms or run a greater risk of relapse even after successful treatment. In fact, patients with social anxiety disorders with extensive deficits in social skills may not respond well to treatment; in one study, social anxiety disorder had the smallest probability of recovery after 12 years of follow-up. ^[26]

The data on the course of social anxiety disorder (SAD) varies between 3% and 80% in retrospective studies and 36% and 93% in prospective studies, suggesting that SAD can have a short or fluctuating course in addition to a chronic course. ^[27]  Limited data indicate a chronic lifetime course for untreated specific phobias. ^[28]  A meta-analysis of 33 randomized exposure-based interventions showed that with treatment, the prognosis of specific phobias is good. ^[29]

The prognosis is determined by several factors, including the following:

• Severity of diagnosis

• level of functioning before onset of symptoms

• Degree of motivation for treatment

• level of support (eg, from family, friends, work, or school)

• Ability to comply with medication regimens, psychotherapeutic regimens, or both

Considerable evidence shows that social anxiety disorder results in significant functional impairment and decreased quality of life. ^{[30, 31]} Despite evidence of impairment, only a minority of individuals with specific phobia ever seek professional treatment.

Phobias are highly comorbid, social anxiety disorder in particular. Most comorbid social anxiety disorders and specific phobias are temporally primary, whereas most comorbid agoraphobia is temporally secondary. Comorbid phobias are generally more severe than pure phobias. Social anxiety disorder is also frequently comorbid with major depressive disorder (MDD) and atypical depression, which results in increased disability. ^{[31, 32]}

There has been some controversy regarding whether anxiety disorders in general and phobic disorders in particular are independently associated with suicidal ideation and suicide attempts (ie, after comorbid mental disorders are adjusted for).

Current evidence suggests that even after adjustment for sociodemographic factors and other mental disorders, the baseline presence of any anxiety disorder—including agoraphobia, social anxiety disorder, and specific phobia—is significantly associated with suicidal ideation and suicide attempts. Additionally, the presence of any anxiety disorder(again, including any phobic disorder) in combination with a mood disorder appears to increase the likelihood of suicide attempts over what would be expected with a mood disorder alone. ^[33]

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

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.

Commonplace abilities such as socializing at gatherings or riding in a small elevator are taken for granted by most people, but patients who experience phobias may have tremendous difficulty in these areas and can be greatly helped significantly by a caring support system. Family and friends can encourage patients to confront fears and help them when necessary (eg, with medication compliance); they can also assist by learning when to stay out of the way and allow patients to venture forth on their own.

Numerous books and self-help groups are available. In addition, patient advocacy groups exist nationwide that provide patients with information, give presentations, and hold 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

• US Food and Drug Administration (FDA), Fighting Phobias, The Things That Go Bump in the Mind

For patient education information, see the Mental Health Center, as well as Anxiety, Panic Attacks, and Hyperventilation.