Intolerance of Uncertainty: A Risk Factor in the Development of Anxiety and Eating Disorders

Anxiety is thought to be an important driving force in the development and perpetuation of eating disorders, and it been clearly shown that anxiety traits or the presence of an anxiety disorder commonly occur prior to the development of an eating disorder (Biol Psychiatry 2007; 16:348).

Cognitive models of psychopathology that emphasize the role of cognitive biases in the etiology and maintenance of problems such as anxiety disorders have also been applied to anorexia nervosa (AN) and bulimia nervosa (BN) (Beck & Clark, 1997; Eysenck, 1992, 1997; Shafran et al., 2007). Intolerance of uncertainty (IU) has been identified as a cognitive bias that may play a large role in these disorders.

The importance of cognitive biases has been supported by research in both children and adults demonstrating that individual differences in how much we focus on stressful or negative emotional stimuli are related to psychopathology (Lonigan & Phillips, 2001). Beck and Clark’s 1997 model proposes that the purpose of the early stages of cognitive processing of incoming information is to assign priority to certain stimuli over others. Thus, cognitive biases direct an individual’s focus of attention and are important in understanding anxiety and other disorders. This model suggests that individuals may have “hypervalent cognitive schemata” (cognitive frameworks), where “reality” in general is viewed as threatening. Thus, information about oneself, the world, and the future is continuously processed as dangerous by some individuals. Barlow (2002) suggested that these schemata act as trait-like sources of vulnerability for the development of anxiety and its related disorders (Barlow, 2002).

More specifically, highly anxious individuals tend to interpret ambiguity or uncertainty as significantly threatening (Muris, 2010). According to Barlow (2002), this cognitive bias, i.e., a general propensity to interpret ambiguity or uncertainty as significantly threatening, almost without exception seems to reflect the presence of anxiety and its disorders, forming a psychological “marker” of anxiety. For example, many stimuli that an individual encounters in daily life are actually ambiguous. For example, entering a social situation or driving a car could be benign but might also indicate impending danger should they be processed as threatening. Research has shown that elevated anxiety and its associated intolerance of uncertainty are potentially fundamental cognitive processes that may be risk factors for the development and maintenance of eating disorders.

How Anxiety Leads to Eating Disorders

Anxiety disorders occur more frequently in AN compared to the general population (Kaye et al., 2004). Subjects with AN may more quickly be conditioned to fear-producing stimuli, and may have greater difficulty with extinction of anxious behaviors (Strober, 2004). Furthermore, there is evidence that there is a shared transmission of anxiety disorders and eating disorders (Keel et al., 2005).

Given this clear association between anxiety and eating disorders, it is not surprising that similar cognitive biases demonstrated in anxious individuals have also been found in persons with eating disorders. Cognitive biases, specifically intolerance of uncertainty, have been shown to have important implications for the development of eating disorders. Sternheim et al. (2010) found that uncertainty was uncomfortable for AN individuals and resulted in a strong desire for control (i.e., organizing and planning).

Persons with eating disorders appear to control their eating, weight, and shape as a way to address their perceived lack of control over interpersonal and overall life stressors, and these behaviors could be an attempt at establishing control and managing internal uncertainty around life events. If there is in fact intolerance of uncertainty in various environments in eating disorders, then focus on the eating disorder itself could be a means of alternate control and thus alleviating the negative emotion from intolerance of uncertainty (IU).

In a study we conducted that examined IU in eating disorders, both individuals with AN and BN had significantly higher intolerance of uncertainty compared with a control group. In addition, individuals with eating disorders and without current anxiety or depressive disorder demonstrate elevated IU compared with controls (Frank et al., 2011). In a nonclinical population of individuals with problematic or normal eating attitudes, Konstantellou et al. (2010) found that those with problematic eating attitudes scored higher on measures of IU. The authors hypothesized that: (1) factors found in individuals with eating disorders, such as need for control, may be due to high levels of IU, and (2) IU may be a risk factor for needing certainty but also a maintaining factor resulting in using the eating disorder as a way to achieve certainty.

One of the most common anxiety disorders found in individuals with eating disorders is generalized anxiety disorder (GAD) (Pallister & Waller, 2008), and Konstantellou et al. (2011) investigated shared vulnerability factors between the two disorders. Results of their study indicated that individuals with eating disorders and GAD scored similarly to those with EDs without GAD on a measure of IU. Additionally, EDs with and without GAD scored significantly higher than controls on intolerance of uncertainty. This indicated that GAD was not driving high IU, which may be inherent to EDs, and thus a potential trait marker.

Along these lines, and consistent with conditions that commonly co-occur with eating disorders, IU has more recently been linked to obsessive-compulsive disorder (OCD) (Tolin, Abramowitz, Brigidi, & Foa, 2003). Not surprisingly, an excessive need for certainty (Makhlouf-Norris & Norris, 1972) significant anxiety around obtaining certainty (Beech & Liddell, 1974; Kozak, Foa, & McCarthy, 1987) has been found in individuals with OCD. Further, it has been suggested that compulsions and rituals may be driven by IU (Tolin et al., 2003).Social anxiety (Carleton, Collimore, & Asmundson, 2010), panic disorder (Buhr & Dugas, 2009), and depression (Dugas, Buhr, & Ladouceur, 2004) have also been linked to IU.

By way of explanation as to how IU leads to symptoms, individuals with ineffective instrumental and emotional coping strategies are challenged in their efforts to adapt. Anxious individuals engage in behaviors designed to achieve certainty in order to gain a sense of control over perceived negative situation (Krohne, 1993). Thus, IU may drive worry, obsessions, compulsions, and other behavior and cognitions that have been linked to various forms of anxiety and eating disorders. However, behaviors and cognitions may serve as less than effective processes through which one attempts to adapt (Holaway et al., 2006).

Clinical Implications

Given the importance that IU may have in the development and maintenance of anxiety and eating disorders, it seems imperative that clinicians assess and treat this cognitive bias. The Intolerance of Uncertainty Scale (IUS; J Anxiety Disord 1998; 12:139) is a helpful self-report measure that specifically assess for this bias in individuals. Treatment should consist of methods that focus on challenging this bias as well as the resultant need for control. Cognitive behavioral techniques that focus on challenging maladaptive beliefs regarding certainty as well as developing exposure and response prevention exercises that result in habituation to feelings of uncertainty and loss of control should be utilized (Starcevic & Berle 2006; Tolin et al., 2003). For example, patients with AN may be directed to attend a social situation (i.e., party) without engaging ahead of time in behaviors potentially designed to establish control, such as excessive exercising.

Conclusion

In conclusion, IU is elevated in most anxiety disorders, as well as in AN and BN, and may be a mediating factor in the expression of anxiety and eating pathology. Therefore, perception of control and intolerance for uncertainty should be particularly considered in the work with these patients since anxious individuals are characterized by their own perceptions of not being able to handle situations that are uncertain.