Comorbidity of panic disorder with agoraphobia and specific phobia: relationship with the subtypes of specific phobia

The study objectives were to determine comorbidity rates for various subtypes of specific phobia (SP) in a sample of patients with the principal diagnosis of panic disorder with agoraphobia (PDA) and to examine the possible etiologic relatedness of these SP subtypes to PDA. Ninety consecutive day clinic patients with PDA were administered the Structured Clinical Interview for DSM-III-R (SCID) modified for DSM-IV. The overall comorbidity rate for SP was 65.6%. The most frequent subtypes of SP were situational phobia and dental phobia, followed by natural environment phobia, phobia of funerals, cemeteries, dead bodies, and other death-related phenomena and objects (referred to as death-related phobia), and blood-injection-injury phobia. Except for death-related phobia, other subtypes of SP clearly tended to precede the onset of PDA, often by many years. The smallest difference between the age of onset for PDA and particular subtypes of SP (temporal distance) was found for death-related phobia, whereas the temporal difference was longer for situational phobia, hospital phobia, and blood-injection-injury phobia. The frequency and temporal distance data suggest that death-related phobia may constitute a risk factor for developing PDA or that it is a prodrome of PDA, whereas situational phobia, hospital phobia, and blood-injection-injury phobia appear to predispose to PDA to a lesser degree. Of the three broadly conceived groups of SP, mutilation phobias (which include death-related phobia, hospital phobia, blood-injection-injury phobia, and dental phobia) appear most etiologically relevant for PDA, with the group of situational phobias (which also includes the natural environment subtype of SP) being less relevant, and animal phobias showing a negligible etiologic relatedness to PDA.