Vulnerability to Anxiety 107
rately screen for anxiety disorders, although better predictive accuracy occurred when
a specific anxiety disorder was targeted by more specific symptom questionnaires (e.g.,
screening for agoraphobia with the Mobility Inventory). Clearly, then, it would be incor-
rect to assume the presence or absence of panic solely on the basis of an individual’s ASI
score.
Prospective Studies
The best empirical evidence that AS is a cognitive personality vulnerability factor for
panic disorder comes from longitudinal studies. Maller and Reiss (1992) reported that
ASI scores predicted frequency and intensity of panic attacks 3 years later. In two sepa-
rate samples of U.S. Air Force cadets assessed before and after a stressful 5 weeks of basic
cadet training, the ASI predicted spontaneous panic attacks that occurred in 6% of the
cadets during the 5-week period (Schmidt, Lerew, & Jackson, 1997, 1999). Additional
analyses revealed that AS uniquely predicted changes in anxious symptoms (i.e., BAI
scores) when controlling for the close association between anxiety and depression. Unex-
pectedly, analysis of the ASI subfactors revealed that it was ASI Mental rather than Physi-
cal Concerns that predicted the spontaneous panic attacks and changes in BAI scores.
In a 4-year community-based longitudinal study, adolescents classified as stable
high or escalating ASI scorers were significantly more likely to experience a panic attack
than low stable scorers (Weens, Hayward, Killen, & Taylor, 2002). However, there was
little evidence that experiencing panic led to subsequent increases in AS (see Schmidt,
Lerew, & Joiner, 2000, for contrary findings). Plehn and Peterson (2002) conducted
an 11-year mailed follow-up survey with first year undergraduates initially assessed for
AS and trait anxiety. After controlling for history of panic symptoms, only Time 1 ASI
was a significant predictor of panic symptoms and panic attacks over an 11-year time
interval. Surprisingly, trait anxiety, not AS, was the only significant predictor of panic
disorder. In a retrospective cross- sectional study ASI Physical Concerns and exposure
to aversive life circumstances predicted panic attacks and agoraphobic avoidance in
the past week (Zvolensky, Kotov, Antipova, & Schmidt, 2005). Together these findings
indicate that high AS constitutes a significant cognitive- personality predisposition for
panic attacks. However, it is unclear which of the ASI subfactors is the most potent
predictor of panic and whether having panic causes a “scarring effect” on AS (i.e., leads
to subsequent increase in AS). McNally (2002) also reminds us that the amount of vari-
ance accounted for by AS is modest, suggesting that other factors are clearly important
in the etiological of panic.
Treatment Effects
There is considerable evidence that AS is responsive to interventions (for reviews, see
McNally, 2002; Zvolensky et al., 2006). For example, a primary preventive program
that targeted AS produced significant reductions in AS that translated into lower sub-
jective fear response to a biological challenge and a significant decrease in Axis I psy-
chopathology over a 2-year follow-up period (Schmidt, Eggleston, et al., 2007). Thus
targeting AS in cognitive therapy should produce immediate and long-term benefits in
anxiety reduction.