“It's not just the judgements—It's that I don’t know”: Intolerance of uncertainty as a predictor of social anxiety

Abstract

Interest in the role of intolerance of uncertainty (IU) – the tendency for a person to consider the possibility of a negative event occurring as unacceptable and threatening irrespective of the probability of its occurrence – in anxiety disorders has been increasing in recent research. IU has been implicated as an important construct associated with generalized anxiety disorder (GAD); however, a growing body of research suggests that levels of IU are also high among individuals with other anxiety disorders. Despite the increasing interest, few studies have examined the relationship between IU and social anxiety (SA). The purpose of the present investigation was to further investigate the relationship between IU and SA. Participants included 286 community members (71% women) from Canada who completed measures of IU, SA, anxiety sensitivity, and fear of negative evaluation (FNE). Regression analyses revealed that the inhibitory anxiety dimension of IU, the fear of socially observable anxiety symptoms dimension of anxiety sensitivity, and the FNE were consistently significant predictors of SA symptoms. Unexpectedly, IU and FNE were often comparable predictors of SA variance. Moreover, participants with SA symptoms consistent with SAD exhibited levels of IU comparable to those reported by participants with worry symptoms consistent with GAD. Comprehensive findings, implications, and directions for future research are discussed.

Introduction

Social anxiety (SA) refers to anxiety or apprehension experienced in interpersonal or performance situations (Watson & Friend, 1969). Individuals with high SA fear being negatively evaluated by others (Rapee and Heimberg, 1997, Stein et al., 1999), making a bad impression, or acting in a way that might be embarrassing (Antony & Swinson, 2000). There is also evidence that SA may result from fearing positive evaluation, suggesting concern related to evaluation in general (Weeks et al., 2008a, Weeks et al., 2008b).

Researchers have shown that social anxiety disorder (SAD) is related to and exacerbated by fears that other people can detect symptoms of SA (e.g., blushing; Rector, Szacun-Shimizu, & Leybman, 2007). Such fears are conceptualized within the anxiety sensitivity (AS; Peterson & Reiss, 1992) construct, which denotes the propensity to appraise anxiety-related somatic sensations, cognitive changes, and social consequences based on expectations of harmful consequences (Reiss and McNally, 1985, Taylor, 1999). Substantial research has demonstrated a direct relationship between the social subscale of the Anxiety Sensitivity Index (ASI; Peterson & Reiss, 1992), and both SA and SAD (Anderson and Hope, 2009, Asmundson and Stein, 1994, Ball et al., 1995) as well as indirect relationships with the ASI somatic and cognitive subscales (Carleton et al., 2009).

The AS construct has been associated with intolerance of uncertainty (IU) – the tendency for a person to consider the possibility of a negative event occurring as unacceptable and threatening irrespective of the probability of its occurrence (Carleton, Sharpe, & Asmundson, 2007) – and may be causally dependent on IU (Carleton, Sharpe, et al., 2007). For persons who are intolerant of uncertainty, engaging in situations with uncertain outcomes may induce and perpetuate a heightened level of anxiety (Dugas, Gosselin, & Landouceur, 2001). People with high IU are more likely to interpret ambiguous information as threatening (Heydayati, Dugas, Buhr, & Francis, 2003), therein exacerbating their physiological arousal (Greco and Roger, 2001, Greco and Roger, 2003) which serves to facilitate self-perpetuating cycles of fear (Barlow, 2002).

IU has been a useful construct in theory and research associated with generalized anxiety disorder (GAD) and obsessive compulsive disorder (Dugas et al., 2001, Holaway et al., 2006); however, it is now also drawing attention from researchers investigating panic disorder (Dugas et al., 2005, Simmons et al., 2008). In contrast, there is a relative paucity of research directly investigating the relationship between IU and SA, including SAD. Researchers have found that IU can predict changes in reported levels of SA (Riskind, Tzur, Williams, Mann, & Shahar, 2007); however, the ability to tolerate the uncertainty associated with social situations may be a critical element in determining SA. For example, in persons with SAD, uncertainty is often associated with SA before a social encounter (e.g., catastrophizing about possible occurrences), during the social encounter (e.g., catastrophizing about ambiguous stimuli), and/or after the social encounter (e.g., catastrophizing about possible consequences; Antony & Rowa, 2008).

The IU and SA relationship has also been directly demonstrated as independent of the established relationships between SA, FNE, and AS using data from a sample of Netherlands participants (Boelen & Reijntjes, 2009). In that study, IU accounted for variance in SA symptoms beyond negative affect, FNE, and AS. While novel and highly coherent, Boelen and Reijntjes's study included (1) only one measure of SA, (2) used the Intolerance of Uncertainty Scale (IUS; Freeston, Rhéaume, Letarte, Dugas, & Ladouceur, 1994), which can be psychometrically unstable (Carleton, Norton, & Asmundson, 2007), (3) did not include a measure of positive affectivity, and (4) used only the ASI total score.

The primary goal of the current study was to replicate the previous finding of a relationship between IU and SA (Boelen & Reijntjes, 2009) with data from a North American community sample. A secondary goal was to extend those findings to include measures of the various facets of SA (i.e., social interaction and performance anxiety, social distress and avoidance), negative and positive affect, as well as psychometrically stable measures of IU and AS. More specifically, the dimensions of IU and AS were not assessed in the previous study despite evidence that the dimensions of each construct function in importantly distinct ways (Collimore et al., 2008, Gosselin et al., 2008, Taylor, 1999). The final goal of this study was to compare levels of IU across participants reporting symptoms congruent with SAD (without co-occurring GAD), relative to GAD (without comorbid SAD), or both (comorbid SAD and GAD), thereby paralleling previous comparative analyses of GAD and panic disorder with agoraphobia (Dugas et al., 2005).