Panic disorder (PD) frequently first presents during adolescence (Noyes, Holt, and Woodman, 1996). While much has been learned about PD in adult populations, however, treatment outcome research about PD in adolescents and youths is almost nonexistent. The reported frequency of the occurrence of PD in childhood and adolescence varies widely depending on the methodology used, in part because most studies have examined retrospective reports of panic or severe anxiety in populations of adult patients with PD, an approach that scholars in the field argue is misleading (von Korff et al., 1985; Klein and Klein, 1990; Abelson

and Alessi, 1992; Klein et al., 1992; Battaglia et al., 1995). Separation anxiety disorder and inhibited temperament in childhood have been described as specific precursors/predictors of later adult panic disorder and agoraphobia (Rutter and Sandberg, 1985; Biederman et al., 1993). The exciting possible connection between ”behavioral inhibition to the unfamiliar” (Biederman et al., 1993)—an early childhood temperamental manifestation of anxiety-and its evolution to agoraphobia and later possibly to PD is being actively explored (Biederman and Rosenbaum, 1994; Pine, 1994; Connolly and Bernstein, 2005). Rosenbaum et al. (1993) reported that 75% of children with separation anxiety at age 21 months had agoraphobia at 7.5 years, while only 7% of 21-montholds without separation anxiety developed agoraphobia. Despite these associations, 70% of the sample of behaviorally inhibited children studied by Biederman et al. (1990) did not go on to develop anxiety disorders, implying that other possibly psychosocial and emotional factors are crucial in the emergence and expression of anxiety disorders.