Women experience a high lifetime rate of anxiety disorders, with approximately 30.5% of women compared to 19.2% of men meeting diagnostic criteria based on epidemiologic studies (Alexander, Dennerstein, Kotz, & Richardson, 2007
). Although much is known about state correlates of anxiety disorders, only few studies have examined the prospective emergence of anxiety disorders in population-based or clinical cohorts. It is these prospective studies that provide evidence supporting a causal role for these (risk) factors, rather than simply reflecting the impact of the anxiety disorder itself.
One potential risk factor for emergence of anxiety disorders is stress. For example, in a prospective study individuals exposed to high psychological job demands (excessive workload, extreme time pressures) were twice as likely to develop generalized anxiety disorder compared to those with low job demands (Melchior et al., 2007). Also, in a longitudinal prospective study, stress was a prospective predictor of first onset panic attacks among white collar workers (Watanabe, Nakao, Tokuyama & Takeda, 2005
). Circumstantial evidence for the role of stress in maintaining or worsening anxiety disorders is provided by a cross-sectional study showing a link between negative life events and higher scores on the State-Trait Anxiety Inventory in college women, (Herrington, Matheny, Curlette, McCarthy, & Penick (2005)
. Furthermore, in panic disorder, life stress was associated with greater symptom severity (Lteif & Mavissakalian, 1995
) and poorer long term outcome in cross-sectional treatment studies (Wade, Monroe, & Michelson, 1993
). Additional circumstantial evidence for association of stress, greater symptom severity, and mediation of anxiety has been found in cross sectional studies of obsessive compulsive disorder, generalized anxiety disorder and social anxiety disorder (Rachman, 1997
; Chorpita & Barlow, 1998
; Kashdan & Steger, 2006
In addition to possible direct effects of stress, there also is support for a diathesis-stress model involving the interaction of life stress and psychosocial risk factors. The diathesis-stress model suggests that psychopathology results from the interaction of risk factors in combination with precipitating circumstances, such as negative life events. Researchers have examined the effects of separate interactions between stress and neuroticism, assertiveness, and anxiety sensitivity. For example, Zvolensky, Kotov, Antipova, and Schmidt (2004)
examined the main and interaction effects of anxiety sensitivity (the fear and preoccupation with anxiety related sensations) and exposure to negative events in predicting panic symptoms. The combination of high levels of exposure to aversive events in interaction with high anxiety sensitivity predicted panic attacks and agoraphobic avoidance. These data are consistent with the role of anxiety sensitivity in prospectively predicting the onset of panic attacks in cadets undergoing the stress of basic training (Schmidt, Lerew, & Jackson 1997
Anxiety sensitivity also appears to be an independent predictor of anxiety, (particularly panic disorder), onset and maintenance (Ehlers, 1995
; McNally, 2002
; Schmidt, Lerew, & Jackson, 1997
, Schmidt, Zvolensky, & Maner, 2006
). Anxiety sensitivity, along with degree of avoidance was a predictor of relapse among patients examined in a prospective naturalistic follow-up study. Anxiety sensitivity also predicted first panic attacks among healthy individuals and those with simple phobias. Attention to anxiety sensitivity as a risk factor is also encouraged by evidence that it is modifiable in accordance with secondary prevention efforts (see Gardenswartz & Craske, 2001
). Anxiety sensitivity has been shown to be predictive of anxiety disorder onset in a non-clinical population. For example, Schmidt, Zvolensky and Maner (2006)
found anxiety sensitivity to predict the incidence of anxiety disorder diagnoses (social anxiety disorder, panic disorder, generalized anxiety disorder, and specific phobias).
In addition to anxiety sensitivity, several other psychosocial predictors have been linked to anxiety. Assertiveness has been repeatedly linked, in cross sectional studies, to anxiety severity in both clinical and non-clinical populations (Chambless, Hunter, & Jackson, 1982
; Moreno-Jimenez, Rodriguez-Munoz, Moreno, & Garrosa, 2007
; Reiter et al., 1991
). Decreased assertiveness may be a common interpersonal challenge faced by people with anxiety as well as a contributor to greater distress when faced by interpersonal issues, and hence serve as a diathesis for more severe anxiety. Additional circumstantial support for a diathesis-stress interaction is provided by cross-sectional studies showing poorer anxiety and health outcomes among those with both high stress and low assertiveness (Moreno-Jimenez, Rodrigues-Munoz, Mereno & Garrosa, 2007
). For example, in response to negative stressful events, those who were low on a measure of assertiveness showed increased social anxiety as compared to those high in assertiveness (Riso, Perez, Roldan & Ferrer, 1988
Patients with anxiety disorders also show more neuroticism than healthy subjects (Carrera et al., 2006
; Weinstock & Whisman, 2006
), and several longitudinal studies have shown that high neuroticism is correlated with subsequent anxiety and depression (Gershuny & Sher, 1998
; Jorm et al., 2000
), including in interaction with traumatic stress (e.g., Schnurr, Friedman, & Rosenberg, 1993
), which supports a diathesis-stress model of anxiety.
In addition to these psychosocial predictors, a history of anxiety disorders is associated with risk of anxiety recurrence. Longitudinal studies have found that anxiety disorders are insidious, with a chronic clinical course, low rates of recovery, and relatively high probabilities of recurrence (.39-.58) (Brown & Barlow, 1995
; Yonkers, Bruce Dyck, & Keller, 2003
; Bruce et al., 2005
); hence past anxiety is an effective predictor of future anxiety.
In the current study, we used participants from the Harvard Study of Moods and Cycles (Harlow et al., 1999
) a prospective longitudinal study examining women in the age range of 36 to 45 years, to examine the psychosocial predictors of a new or recurrent onset of anxiety in women. More specifically, for the purpose of predicting onset of anxiety episodes we investigated the role of stressful (negative) life events considered alone and in interaction with three psychosocial variables of interest: anxiety sensitivity, assertiveness, and neuroticism. For this study we excluded women with a history of depression, as previous research has tied depression with several of the psychosocial variables of interest (Ball, Otto, Pollack, Uccello & Rosenbaum, 1995; Otto, Pollack, Fava, Uccello & Rosenbaum, 1995
; Otto et al., 1997
; Jain, Blais, Otto, Hirshfeld & Sachs, 1999
We hypothesize that those who have high anxiety sensitivity would be more likely to have an onset of anxiety as previously demonstrated in research on panic and other anxiety disorders. Additionally we hypothesize that low assertiveness as well as high levels of neuroticism will predict higher rates of anxiety onset. Lastly we hypothesize that negative life events will moderate these relationships.