Generalized Anxiety Disorder 407
are often elicited by the personal goals, life tasks, and current concerns of the indi-
vidual. Moreover, there is a close relationship between intrusive thoughts and worry,
with experimental studies indicating that brief periods of worry induction result in a
subsequent increase in negative intrusive thoughts (Borkovec, Robinson, et al., 1983;
Pruzinsky & Borkovec, 1990; York et al., 1987; see also Ruscio & Borkovec, 2004;
Wells, 2005). However, no studies have directly examined whether worry can arise
from unwanted intrusive thoughts, so empirical support for Hypothesis 1 is tentative at
this time.
Clinician Guideline 10.9
Individuals’ personal goals, prominent life tasks, and significant current concerns will deter-
mine the main themes of their worry content. A contextual analysis that takes into account
the presence of intrusive thoughts and images is needed to determine the factors that trigger
excessive worry.Hypothesis 2
Maladaptive beliefs about general threat, personal vulnerability, intolerance of uncertainty,
and the nature of worry relevant to valued personal goals and vital interests will be more
characteristic of GAD than non-GAD individuals.
Many cognitive theories of GAD view maladaptive beliefs about personal threat,
vulnerability, risk, and uncertainty as central to the pathogenesis of chronic worry (e.g.,
Beck et al., 1985, 2005; Dugas, Gagnon, et al., 1998; Freeston et al., 1994; Wells, 1995,
1999). Unfortunately, though, specific GAD self- report measures do not exist for the
threat and personal vulnerability schema content described in Table 10.2. However,
there is strong evidence that threat schemas play a critical role in GAD. In Chapter 3
studies finding a higher rate of automatic threat cognitions in anxiety often included
GAD patients in their samples (see Hypothesis 6) and many studies showing an elabora-
tive threat interpretation bias in anxiety were based on GAD patients (see Hypothesis
8). In their review MacLeod and Rutherford (2004) concluded that GAD is character-
ized by an automatic attentional bias for threat during the encoding of information
and a selective threat interpretation bias in ambiguous situations. However, Coles and
Heimberg (2002) concluded that an explicit threat memory bias was not evident in
GAD, a conclusion that would appear to run counter to the current hypothesis. They
suggest that the lack of findings may be due to difficulty in developing a set of threat
stimuli that is specific to the idiosyncratic worry domains of GAD patients.
Cognitive research on GAD has tended to focus on intolerance of uncertainty and
metacognitive beliefs because these constructs may be more specific to the disorder.
Koerner and Dugas (2006) have argued that intolerance of uncertainty and ambi-
guity may be the “threat” that is unique to GAD. To assess this important schema
construct, a 27-item Intolerance of Uncertainty Scale (IUS; Freeston et al., 1994) was
developed that assesses beliefs about the negative consequences and unacceptability of
being uncertain. Various studies have shown a specific relationship between the IUS
and self- report worry measures in GAD and nonclinical samples, and individuals with