A persistent and unreasonable fear of a particular object, activity, or situation

Introduction

Although phobia connotes fear in lay language, in the lexicon of medical disorders it takes on extra meaning. Phobias are characterized by a pronounced fear or anxiety response, compelling desire to avoid the target of the phobia, chronic duration, and significant distress or impairment as a result of the phobia. Patients with true phobias describe the fear response occurring almost every time the situation or object is encountered, worsening with proximity to the source of phobia, and rapidly ceasing once contact ends. A number of categories of phobias exist, but all phobias fall within the family of anxiety disorders. Anticipated revisions to phobias in the newest edition of the psychiatric diagnostic manual, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), are mostly minor, and thus the basic conceptualization of phobias appears stable for the time being.

Phenomenology of Specific Phobias

Specific Phobia

Specific phobias affect between 5 and 10% of the population. The object of the phobia can be animate or inanimate objects or specific situations. The essence of specific phobia is that whenever people come into contact with the intensely feared object or situation, or even suspect that they might, they must either flee from it or tolerate it with severe anxiety. Such ongoing monitoring or vigilance, and the concurrent avoidance, cause phobias to be extremely disabling. Everyday life can be a minefield of potential horrors. Fear, on the other hand, is not associated with such an intense reaction. A feared object can be confronted without a high degree of functional impairment.

The most common phobia is of illness or injury, such as blood phobia, whereas the most frequent intense fear is of snakes. There are wide gender differences among the specific phobias, with fear of storms, for example, occurring almost entirely among women and agoraphobia occurring approximately equally between men and women. Age of onset varies widely among the phobias. Most phobias typically begin in early childhood; for example, blood phobia usually starts at approximately age 7 years. The age of onset for agoraphobia and claustrophobia ranges from the late teens to the early twenties.

Agoraphobia and claustrophobia are linked in other ways. In agoraphobia, there is severe anxiety about being in places or situations from which escape would be difficult or extremely embarrassing or in which help would not be available in the event that the person has a panic attack or symptoms. In claustrophobia there is severe fear of closed spaces, with similar intense worry about lack of help or escape. Panic disorder, agoraphobia, and claustrophobia all have similar ages of onset, with frequent comorbidity.

Clinical features

Phobic neuroses differ from anxiety neuroses in that the phobic anxiety arises only in specific circumstances, whereas patients with anxiety neuroses are generally anxious. Claustrophobia (fear of closed spaces) is probably the most common phobic disorder. Magnetic resonance imaging (MRI) is sometimes impossible to carry out because of claustrophobia.

Some of the other more common specific phobias are centred around heights, tunnels, driving, water, flying, insects, dogs and injuries involving blood. When phobias are centred on threats such as flying, anaesthetics or dental treatment, normal life is possible if such threats are avoided. Phobias may also be a minor part of a more severe disorder, such as depression, obsessive neurosis, anxiety state, personality disorder or schizophrenia.

Specific Phobia

Phobic disorders are related to avoidance precipitated by certain triggers, such as animals, situations, or places. Fears are common among children. Among children aged 7 and 11 years, the prevalence of specific phobias is approximately 2.4% and 0.9%, respectively (Anderson et al, 1987; Silverman and Moreno, 2005), with a marked female preponderance. It is thought that parental history of anxiety disorder (particularly phobias), anxious temperament, and traumatic occurrences (e.g., a dog bite, leading to dog phobia) all play a role in the genesis of phobic disorders.

Many phobic disorders never come to medical attention because those suffering from the disorder can simply alter their life to avoid contact with the precipitant for their phobic reactions. However, children with simple phobia that leads to school avoidance often are referred for treatment of “school refusal.” The differentiation between a fear and phobia is in the degree of anxiety in response to exposure, the extent of the avoidant behavior, and the concomitant functional impairment. School phobia may result in the avoidance of school, but the fear is not related to separation, as in the case of separation anxiety disorder. Behavioral interventions have a well-documented efficacy in the treatment of phobias. Such interventions include desensitization through graduated imagined or real exposure.

Specific Phobia

Specific phobia is a heterogeneous group of conditions that includes phobia of animals, blood-injection-injury phobia (i.e., phobia of the sight of blood, injured tissues, mutilation of the body, or needle penetrating the skin), situational phobia (i.e., phobia of driving or flying, claustrophobia), natural environment phobia (i.e., phobia of water, heights, storms) and other “unclassified” phobias such as dental phobia and phobia of choking or vomiting. The affected individuals are excessively afraid of particular objects, situations, activities, or phenomena (i.e., “phobic stimuli”) because of the perceived threat posed by them. The threat is based on the specific dangers associated with phobic stimuli (e.g., a danger of suffocation while the person is in a small, enclosed place) or disgust. The feeling of disgust is experienced vis-à-vis certain animals, especially insects, and stimuli that serve as reminders of the animal origin and mortality of the humans (i.e., the sight of blood, wounds, or needle penetrating the skin). The blood-injection-injury phobia is a unique type of phobia as it is characterized by a vasovagal reaction, with bradycardia, hypotension, and fainting; unlike all other phobias, it is as common in males as it is in females (Table 1). In all specific phobias, phobic stimuli are avoided as much as possible; if avoidance is not possible, phobic stimuli are endured with much fear or distress (Table 2).

Although specific phobia is common in the community (Table 1), its frequency is lower in the treatment-seeking populations, suggesting that specific phobia may cause less impairment than most other anxiety disorders and/or that individuals with specific phobia are less likely to seek professional help. Indeed, only about 8% of individuals with specific phobia may seek treatment,16 and most use avoidance as their coping strategy. When they seek professional help, that is usually because changes in their life circumstances prevent them from continuing to avoid their phobic stimuli (e.g., commencing a job that involves frequent travel by plane makes avoidance of flying impossible).

Similar to other anxiety disorders, genetic predisposition to specific phobia is not specific. Many phobias develop as a result of learning. This can occur through a traumatic conditioning (direct aversive experience with the phobic stimulus), vicarious learning (observation of the fear in others) or transmission of the information on the dangerousness of certain objects or situations. Some types of specific phobia (e.g., phobia of heights or water, spider phobia) have been posited to represent “innate” fears, which are not a product of learning; these phobias may have a survival or evolutionary value.17

Agoraphobia

Phobias are characterized by excessive fear of a specific object or circumstance. The DSM-IV distinguishes three classes of phobia: agoraphobia, specific phobia, and social phobia. Agoraphobia is defined as fear of being in situations from which escape might be difficult or in which help may not be available in the event of a full or partial panic attack. The fear may result in phobic avoidance of crowds or travel outside the home while alone. In moderate cases, exposure to the feared situations may be endured. In more severe cases of agoraphobia, the person may become completely housebound in order to avoid all feared situations.

Phobic disorders

Phobic disorders consist of persistent or recurrent irrational fear of an object, activity, or situation that results in the compelling desire to avoid the phobic stimulus.137 In old age they are associated with higher rates of medical and of other psychiatric morbidity but are frequently found in the absence of other psychiatric disorder.133 Agoraphobia is often triggered by the traumatic experience or acute physical ill health.137

The longitudinal course of phobic disorders in old age is unclear. Individuals with one phobia may develop another. Fear of crime is particularly common in old age, leading to fear of going out and to nighttime fearfulness. Social phobias in old age have usually developed earlier in life and persisted; they tend to be chronic and unremitting.138 Comorbidity with agoraphobia, specific phobia, depression, and alcohol abuse is common.139 Older people rarely seek treatment but change their life to accommodate their avoidance. Anxiolytics provide only symptomatic relief and are best avoided because of their dependency potential.137

Specific phobia

Phobic symptoms

Phobia following trauma may represent ‘stretching’ of the phobic elements of PTSD into a syndrome in its own right. Thompson (1965) found an incidence of 21% in his series of 500 accident victims. The phobias were not of a classical form and were in the main related to the injury, such as fear of driving following a car crash or fear of heights following a fall. In the two cases in which there was evidence of a classical claustrophobia (fear of enclosed places), there was a history of pre-existing neurosis. The phobia pattern following trauma may be directly derived from the circumstances of the injury (Hodge 1971). Patients will demonstrate avoidance or reduction of the activity related to the trauma (Kuch et al 1985).