Course and Natural History
As discussed earlier, the mean age at onset of social phobia is in the middle teens. The age at onset of specific phobias varies depending on the phobia type, with phobias of animals, blood, storms and water tending to begin in early childhood, phobias of heights beginning in the teens, and situational phobias beginning in the late teens to middle twenties. Although childhood fears are often transient (e.g., most children outgrow fear of the dark without treatment), fears that persist into adulthood usually have a chronic course unless treated.
Although many phobias begin after a traumatic event, many patients do not recall the specific onset of their fear, and few empirical data have examined the initial period after the fear onset. Clinically, however, some patients report a sudden onset of fear, whereas others report a more gradual onset. Studies exam-ining the onset of phobias have tended to assess the onset of the fear rather than the onset of the phobia (i.e., the point at which the fear creates significant distress or functional impairment). A study by Antony and colleagues (1997) suggests that the fear and phobia onset are often not the same. Patients with specific pho-bias of heights, animals, blood-injection, or driving were asked to estimate the earliest age at which they could recall having their fear and the earliest age at which they could recall experiencing distress or functional impairment due to their fear. Anecdotally, the types of factors leading to the transition from fear to pho-bia included gradual increases in the intensity of fear, additional traumatic events (e.g., panic attacks, car accidents), increased life stress and changes in living situation (e.g., starting a job that requires exposure to heights). Similarly, it is not unusual for indi-viduals with social phobia to report having been shy as children, although their anxiety may not have reached phobic proportions until later.