Evaluating the unique contribution of intolerance of uncertainty relative to other cognitive vulnerability factors in anxiety psychopathology

Abstract

Background

Intolerance of uncertainty (IU) is a cognitive vulnerability factor associated with a wide range of anxiety psychopathology. Other cognitive vulnerabilities such as anxiety sensitivity (AS), distress tolerance (DT), and discomfort intolerance (DI) have also been investigated as constructs of interest across anxiety disorders. As researchers increasingly uncover viable transdiagnostic vulnerabilities to anxiety, it becomes important to determine the degree of overlap between these constructs.

Methods

The present studies examined the unique relationships between IU, other vulnerability factors (AS, DT, and DI) and social anxiety, obsessive-compulsive, and worry symptoms across two nonclinical samples (n=217, n=241).

Results

Findings were highly consistent across samples. IU was significantly associated with anxiety symptoms in all analyses, even when accounting for other transdiagnostic risk variables. Anxiety sensitivity, was uniquely related to social anxiety and obsessive-compulsive symptoms in all analyses, but was related to worry in only one study. Distress tolerance was only uniquely associated with worry. Discomfort intolerance was not uniquely related to the anxiety symptoms in any analyses.

Limitations

Future research should attempt to replicate the findings in a clinical population and utilize a longitudinal design.

Conclusions

The robust and incremental relationships between IU and anxiety symptoms suggests the potential benefit of targeting IU in the context of transdiagnostic anxiety treatments.

Introduction

Intolerance of uncertainty (IU) is an individual difference variable that has emerged in recent research as a construct of interest within anxiety psychopathology. IU is defined as “a cognitive bias that affects how a person perceives, interprets, and responds to uncertain situations on a cognitive, emotional, and behavioral level” (Dugas et al., 2004). Individuals high in IU experience the possibility of a future negative event as threatening and unacceptable, regardless of the probability of the event actually happening (Dugas et al., 2001). Generalized anxiety disorder (GAD) and worry were the first forms of anxiety psychopathology thought to be associated with IU (Dugas and Ladouceur, 2000, Holaway et al., 2006). As a central tenet in their cognitive model of GAD, Dugas and Robichaud (2007) conceptualize IU as a dispositional characteristic of individuals at risk for GAD. Within this model, those high in IU interpret ambiguous situations as more threatening relative to those low in IU. Due to the inherent uncertainty present in everyday life, IU is seen as a contributing factor to the avoidance and chronic worry seen in GAD. More recently, IU has been associated with a wide range of anxiety conditions including obsessive-compulsive disorder (OCD; Holaway et al., 2006), social anxiety symptoms (Boelen and Reijntjes, 2009, Carleton et al., 2010), hoarding symptoms (Oglesby et al., 2012), as well as depression (McEvoy and Mahoney, 2011). Within these disorders, IU is proposed to be a vulnerability factor contributing to increased avoidance behaviors, such as worry and compulsive checking in GAD and OCD respectively. In addition, given the recent research linking IU to a myriad of anxiety and depressive disorders, IU has been proposed as an important transdiagnostic maintaining factor (McEvoy and Mahoney, 2011).

The interest in IU as a transdiagnostic construct is recent, but extensive work exists for other cognitive vulnerability factors for anxiety. Anxiety sensitivity (AS) is a well-established construct referring to the fear of the consequences of anxiety-related sensations (Reiss and McNally, 1985). Research has established AS as a risk factor for anxiety disorders and found that individuals with anxiety disorders have higher AS than individuals without an anxiety disorder (Kearney et al., 1997, Rabian et al., 1993, Taylor et al., 1992). Distress tolerance (DT) is an additional variable of interest in anxiety disorder research. DT refers to an individual's ability to experience and endure negative emotional states (Simons and Gaher, 2005). Individuals that are low in DT display a decreased capacity to tolerate negative emotions, whereas individuals that are high in DT display an increased capacity to tolerate negative emotions. Low DT has been associated with a variety of negative outcomes such as anxiety and depressive symptoms, eating psychopathology, and problematic substance use (Anestis et al., 2007, O'Cleirigh et al., 2007, Simons et al., 2005). Similar to DT, discomfort intolerance (DI) is a construct used to measure the ability to tolerate uncomfortable physical sensations (Schmidt et al., 2006a, Schmidt et al., 2006b). Previous research has suggested that DI may be an additional risk factor for anxiety psychopathology (Schmidt et al., 2006a, Schmidt et al., 2006b, Schmidt et al., 2007).

Recent work has examined the relationships between cognitive vulnerability factors. Bernstein et al. (2009) proposed a hierarchical model of AS, DT, and DI. According to their model, AS and DT are distinct yet related lower order factors of a common higher order affect tolerance and sensitivity factor, while DI is a distinct construct. Another study found AS to be a subfactor of DT within a higher order affect tolerance factor, with DI being part of a distinct higher order factor of physical intolerance (Mitchell et al., 2013). Confirmatory factor analysis revealed that AS and IU are better modeled as separate, correlated factors (r=0.68) rather than loading on a single higher order factor (Carleton et al., 2007). These results suggest that AS and IU are related yet distinct constructs. Other investigators have posited that AS may function only as a mediator of the relationship between negative affect and certain anxiety symptoms, while IU explains additional independent variance above and beyond negative affect in certain anxiety symptoms (Norton and Mehta, 2007, Norton et al., 2005).

A concern in the development of treatments targeting cognitive vulnerability factors is the degree of overlap between these constructs and specific anxiety symptoms. One study found that AS and IU are independently related to neuroticism (Sexton et al., 2003), a personality trait associated with anxiety disorders (Barlow, 2002). Studies have also revealed that IU predicts significant variance in social anxiety symptoms and worry above and beyond AS and neuroticism (Boelen and Reijntjes, 2009, Carleton et al., 2010, Dugas et al., 2001). However, there are no studies to date that investigate the unique contribution of IU across different anxiety disorder symptoms above and beyond the effects of AS, DT, and DI.

The present study seeks to examine the unique relationship between IU and symptoms of social anxiety disorder, obsessive-compulsive disorder, and generalized worry controlling for the effects of AS, DT, and DI. The main hypothesis for the study is that IU will show a unique relationship with social anxiety, obsessive-compulsive, and worry symptoms above and beyond the contributions of AS, DT, and DI.