Item-Level Analysis of the Intolerance of Uncertainty Scale in Youth with ASD
Intolerance of uncertainty (IU) is a transdiagnostic construct in which individuals experience negative emotional, behavioral, and cognitive reactions to uncertain situations. In typically developing (TD) individuals, IU has been associated with anxiety, obsessive-compulsive disorder, and depression. Multiple studies have reported higher rates of IU in youth with ASD compared to TD peers (Chamberlain et al., 2013; Kreiser et al., 2016). IU has also been increasingly identified as a key variable in the relationship between ASD and anxiety. It has been found to mediate the relationship between ASD and anxiety (Boulter et al., 2014), to predict outcomes of CBT for anxiety (Keefer et al., 2016), and to be associated with ASD symptoms when controlling for anxiety (Neil et al., 2016; Kreiser et al., 2016). Thus far, the main tool to assess IU has been the Intolerance of Uncertainty Scale (IUS). Studies that have used this instrument have examined total IUS scores, and no studies have examined whether specific IU traits may be particularly heightened in youth with ASD.
To examine differences in the 27 questions on the IUS between youth with ASD and TD controls using parent and child report.
One hundred and sixteen youth, 8 through 16 years, and 97 parents were enrolled for this study from ongoing research studies. Two groups of children were examined: children with ASD and TD children without psychopathology. All participants in the ASD group were well-characterized using the ADOS/ADOS-2, ADI-R and WISC-IV (VCI greater than 70). IU was assessed using the Intolerance of Uncertainty Scale for Children, Parent and Child Report (IUS-P, IUS-C; Comer et al., 2009), a 27 item rating scale which has demonstrated good internal consistency in the ASD population (Kreiser et al., 2016) and in TD youth (Comer et al., 2009).
Results of the logistic regression analysis indicated that children with ASD reported significantly higher scores on ten IUS-C items compared to TD controls (See Table 1). Seven of these ten items have themes of negative emotions (“I can’t relax,” “I get frustrated”) and cognitions (“It makes life hard,” “It’s not fair,” “It’s hard for me to have fun,” “I am not great.”) when experiencing uncertainty. Additional items contained themes related to “behavioral paralysis,” which refers to avoidant-oriented responses to uncertainty. The highest odd ratio was associated with the item, “Being unsure of things means I am not great,” indicating a connection between high IU and negative self-appraisal. Parents, however, reported broad based differences in IU with 20 items that were significantly greater in the ASD group compared to the control group. These items overlapped with most child report items, and similarly contained themes of negative emotions and cognitions, as well as “behavioral paralysis”.
Children with ASD report dysphoric emotions and cognitions when experiencing IU. This suggests that IU may be associated with different types of psychopathology including depression, irritability, and behavioral dysregulation. Clinicians may consider incorporating questions about IU in their mental health assessment and in the development of psychosocial interventions for youth with ASD.