into panic disorder (PD) and generalized anxiety disorder
(GAD) on the basis of Klein's (1964) observation of
differential responsivity to drugs. In DSM-III-R and
DSM-IV (American Psychiatric Association 1987; 1994),
GAD was further defined with chronic worry as its central
feature.
Whereas the autonomic characteristics of PD have been
studied extensively (e.g., Friedman et al 1993; Jacob and
Waldstein 1991; Pohl et al 1990; Roth et al 1986), relatively
few studies have examined the autonomic characteristics of
GAD. Moreover, little research has been conducted on
autonomic activity during worry. Given the primary role of
worry in GAD, this process may be a critical mediator in the
link between ANS activity and GAD.
One problem with the studies that have examined
autonomic characteristics of anxiety has been their failure
to address the well-documented complexity and specificity