anxiety disorder (GAD). The only studies that have investigated the associations between the FMPS and HMPS subscales and pathological worry have used student samples (Buhr & Dugas, 2006; Flett, Hewitt, Endler, & Tassone, 1994; Kawamura, Hunt, Frost, & DiBartolo, 2001; Santanello & Gardner, 2007; Stoeber & Joormann, 2001). Flett et al. (1994) reported that SPP and SOP were significantly correlated with the autonomic arousal and cognitive worry facets of state anxiety as assessed by the Endler Multidimensional Anxiety Scales (Endler, Edwards, & Vitelli, 1991). Nevertheless, when males and females were considered separately, SPP remained related to cognitive worry in both genders; however, SOP was only associated with cognitive worry in females. Buhr and Dugas (2006) discovered that SPP and SOP were each significantly correlated with pathological worry as measured by the Penn State Worry Questionnaire (PSWQ; Meyer, Miller, Metzger, & Borkovec, 1990)
after accounting for gender. SOP still significantly predicted PSWQ after accounting for demographics and intolerance of uncertainty, but SPP did not. This was
important as it suggested that SOP explains additional variance in pathological worry to that explained by intolerance of uncertainty, which is an important construct in an established model of GAD (Dugas, Gagnon, LaDouceur, & Freeston, 1998).
Three studies have investigated the associations between the FMPS scales and pathological worry in student samples (Kawamura et al., 2001; Santanello & Gardner, 2007; Stoeber & Joormann, 2001). These studies each examined whether the FMPS dimensions are uniquely related to pathological worry after controlling for depression and anxiety. Kawamura et al. (2001) found that MEC was significantly correlated with three anxiety factors: social/worry/trait anxiety, post-traumatic stress and obsessive-compulsive symptoms; however, MEC only significantly predicted social/worry/trait anxiety after accounting for depression. PS was only related to post-traumatic stress disorder symptoms and this became non-significant after accounting for depression. Kawamura et al. (2001) asserted that such findings support the association between MEC and social/worry/trait anxiety being important of its own accord and not just emerging due to perfectionism being associated with depression (Enns et al., 2001; Kawamura et al., 2001). Nevertheless, as the
composite construct of MEC was used as a measure of perfectionism, one cannot determine which dimensions of MEC are related to social/worry/trait anxiety. Moreover, as pathological worry was part of a composite construct with trait anxiety and social anxiety, one cannot dismiss that the findings may be accounted for by the relationships perfectionism has with social anxiety (e.g., Frost et al., 1990) and trait anxiety (Hewitt & Flett, 1991a) in non-clinical samples.
Stoeber and Joormann (2001) and Santanello and Gardner (2007) separated MEC into smaller composite constructs of CM+DA and PE+PC and assessed whether these constructs, as well as PS, were associated with PSWQ scores. Stoeber and Joormann (2001) reported that CM+DA was significantly related to PSWQ scores after accounting for depression, anxiety and the amount of everyday worries. PE+PC and PS were not significantly related to PSWQ scores (Stoeber & Joormann, 2001). Santanello and Gardner (2007) found that CM+DA was significantly
associated with PSWQ scores after partialling out depression, social anxiety and experiential avoidance. PE+PC and PS did not have significant associations with PSWQ scores. Thus, there is evidence to support there being a relationship between CM+DA and pathological worry in student samples (Santanello & Gardner, 2007; Stoeber & Joormann, 2001); however, these findings cannot be generalised to clinical samples with GAD.
To date, there have been no studies examining the relationship between Shafran et al.’s (2002) clinical perfectionism construct and pathological worry across student or clinical samples. Studies have only examined the relationship between CPQ scores and measures of anxiety and stress (Chang & Sanna, 2012; Egan, Shafran, et al., 2014). Egan, Shafran, et al. (2014) reported that students with DASS- anxiety scores in the upper quartile of the sample had significantly higher CPQ scores than students with DASS-anxiety scores in the lower quartile of the sample. Chang and Sanna (2012) found that CPQ scores significantly predicted anxiety scores on the Beck Anxiety Inventory (Beck, Epstein, Brown, & Steer, 1988), as well as stress scores on the Perceived Stress Scale (Cohen, Kamarck, &
supported associations between CPQ scores, anxiety and stress, causal inferences cannot be made and findings cannot be generalised to clinical populations.
To date, research has not investigated the relationships between
perfectionism dimensions and pathological worry in a sample of individuals with GAD. This is a limitation of the perfectionism literature, particularly when compared to the number of studies that have investigated the relationships between
perfectionism dimensions and the symptoms of other psychological disorders (Egan et al., 2011). Furthermore, as gender has been shown to moderate the relationship between perfectionism dimensions and pathological worry (e.g., Flett et al., 1994) and perfectionism dimensions have demonstrated associations with anxiety and depression (Egan et al., 2011), there is a need to investigate the associations between perfectionism dimensions and pathological worry after controlling for gender, depression and anxiety. Evidence of significant associations between perfectionism dimensions and pathological worry after controlling for these confounds would further support perfectionism being a transdiagnostic process (Egan et al., 2011). In Study I of this PhD thesis, the associations between perfectionism dimensions and pathological worry are investigated in individuals with elevated perfectionism and GAD who presented for perfectionism treatment.
Furthermore, while research has examined whether perfectionism
dimensions can predict whether individuals have other disorders such as OCD, social phobia and panic disorder with or without agoraphobia (Antony, Purdon, et al., 1998), studies have not examined whether dimensions of perfectionism can predict a principal diagnosis of GAD from a clinical sample with a range of diagnoses. There is a need to investigate this association after controlling for gender and depression (Egan et al., 2011; Flett et al., 1994). In Study I of this PhD thesis, the utility of
perfectionism dimensions in predicting a principal diagnosis of GAD is examined in a clinical sample with elevated perfectionism and a range of diagnoses who
presented for perfectionism treatment. Evidence of significant associations between perfectionism dimensions, pathological worry and a principal diagnosis of GAD will provide a rationale for Study II of this thesis and future studies to investigate whether a perfectionism intervention can reduce the symptoms of GAD along with the
symptoms of other disorders.