Understanding anxiety in adults on the autism spectrum: An investigation of its relationship with intolerance of uncertainty, sensory sensitivities and repetitive behaviours.
Intolerance of uncertainty carries sensory and sameness issues straight into anxiety for autistic adults.
01Research in Context
What this study did
Hwang et al. (2020) asked autistic adults to fill out four surveys. The surveys measured anxiety, sensory sensitivities, insistence on sameness, and intolerance of uncertainty.
The team then used statistics to see if intolerance of uncertainty acts like a bridge. They wanted to know if it carries the effect of sensory issues and sameness straight into anxiety.
What they found
Intolerance of uncertainty fully explained the link. When it was in the model, sensory sensitivities and insistence on sameness no longer directly predicted anxiety.
In plain words, if you lower intolerance of uncertainty, you likely lower anxiety, even when sensory issues stay the same.
How this fits with other research
MacLennan et al. (2021) found the same bridge in preschoolers. Sensory over-responsivity predicted both intolerance of uncertainty and anxiety in three- to five-year-olds, showing the pathway starts early.
Uljarević et al. (2018) saw the pattern in adults with Williams syndrome. Sensory hypersensitivity and intolerance of uncertainty each added unique weight to anxiety scores, a near mirror of the autism data.
Sutton et al. (2022) widened the lens to autistic teens and young adults. They added emotion dysregulation and showed it works alongside intolerance of uncertainty to fuel anxiety and depression.
Taken together, the pathway looks the same across ages and diagnoses: sensory disruption raises uncertainty, and uncertainty raises anxiety.
Why it matters
You can treat sensory triggers all day, but if the client still feels the world is unpredictable, anxiety will stay. Build tolerance for small changes into every session: shuffle the order of tasks, vary the color of flash cards, or let the timer run five seconds longer. Praise flexible behavior and use visual schedules that show "what could happen." When uncertainty feels manageable, sensory defenses and rigidity often ease without extra work.
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02At a glance
03Original abstract
Anxiety is present in high rates in both children and adults on the autism spectrum. An increasing number of studies have highlighted the potentially important role that intolerance of uncertainty may have in anxiety for those on the spectrum, as well as their interrelationships with sensory sensitivities and repetitive behaviours. In response to a lack of studies involving adults, this study examined self-report survey data regarding intolerance of uncertainty, sensory sensitivities, repetitive behaviours and anxiety in a sample of 176 adults on the autism spectrum (mean age = 42). Intolerance of uncertainty and anxiety were both found to be elevated relative to non-autistic adults (N = 116) and significant, positive correlations were found between intolerance of uncertainty, anxiety, repetitive behaviours and sensory sensitivities in those on the spectrum. Intolerance of uncertainty was found to be a significant mediator between sensory sensitivities and anxiety, as well as between anxiety and insistence on sameness behaviours. These results were not sensitive to age. Intolerance of uncertainty is an important factor to be considered in the conceptualisation and management of elevated rates of anxiety for adults on the autism spectrum.
Autism : the international journal of research and practice, 2020 · doi:10.1177/1362361319868907