Specific Phobias
Specific phobias are the second most common anxiety disorder, after social phobia.
They are, however, less impressive because they are mostly less incapacitating than other anxiety disorders. A specific phobia is defined as a circumscribed, persistent, and unreasonable fear of a particular object or situation. Exposure to this phobic stimulus is associated with an acute and severe anxiety reaction. Although individuals with specific phobias recognise their fear is unrealistic, most adjust their lifestyle so that they can completely avoid or at least minimise this contact (Fyer, 1998). Within the specific phobia category there is considerable heterogeneity. In the DSM-IV, four subtypes are defined, and animal phobias, situational phobias, blood-injury phobia, and nature-environment phobia are distinguished. The first three have been differentiated on the basis of a combination of factors including age at onset, symptom response, heritability and biological challenges (Fyer, 1998; Verburg et al., 1994). On the separate position of the nature-environment phobia there is less consensus (Fyer, 1998).
Prevalence
The NCS rates for one-month and lifetime specific phobia are 5.5% and 11.3%, respectively (Magee et al., 1996). Among women, fear of animals is most frequent; fear of heights is most prevalent in men (Curtis et al., 1998). In a study addressing blood-injury phobia a lifetime prevalence of 3.5% was found, and a mean age at onset was 5.5 years. Also noteworthy is that none of the subjects had ever sought professional treatment (Bienvenu and Eaton, 1998).
Demographics and Risk Factors
Female to male ratio for specific phobia is 2.3: 1. In the NCS females had a lifetime prevalence of 15.7% and men 6.7% (Kessler et al., 1994).
Natural Course
Simple phobia appeared in a study by Goisman et al. (1998) to be a chronic illness of moderate severity for which behavioural treatment methods of recognised efficacy were infrequently being used. The number of fears, independent of type, predicts impairment and professional help-seeking (Chapman et al., 1993; Curtis et al., 1998).
Comorbidity
Simple phobia is highly comorbid with other disorders; 83.4% of persons with simple phobia reported at least one lifetime comorbid disorder (Magee et al., 1996). The other anxiety disorders and major depression are most frequent. Also, specific phobia is frequently diagnosed as a comorbid disorder in other anxiety disorders (Goisman et al., 1998).
