Simple phobia: evidence for heterogeneity.

Although simple phobia is a residual category in DSM-III, clinical experience suggests at least four subtypes of this group. To test the validity of the subtypes, the authors compared patients with one of four simple phobias subtypes (n: animal-insect = 25, blood-injury = 9, situational = 46, choking-vomit = 8). Significant sex differences were observed; all animal and insect phobics and seven of eight choking-vomit phobics were female, while the other two groups showed approximately equal numbers of males and females. Mean age of onset was significantly older for situational phobics than animal-insect or blood-injury phobics; choking-vomit probands were intermediate. Frequency of situational phobias differed significantly among relatives of the four proband groups, with highest frequency being found among situational probands. Thus, these clinical and epidemiological variables support the separation of simple phobia into at least these four diagnostic groups.