Anxiety Disorders are a frequent co-occurring (comorbid) problem for children and youth with ASD. Although prevalence rates vary from 11% to 84%, most studies indicate that approximately one-half of children with ASD meet criteria for at least one anxiety disorder. Of all types of anxiety disorders, specific phobia is the most common, with prevalence estimates ranging from 31% to 64%. In contrast, estimates of phobias in children in the general population range from 5% to 18%.
Unusual fears have long been recognized as a feature ofautism. In fact, 70 years ago, Leo Kanner wrote in his initial account of autism that “loud noises and moving objects” are “reacted to with horror” and things like “tricycles, swings, elevators, vacuum cleaners, running water, gas burners, mechanical toys, egg beaters, even the wind could on occasions bring about a major panic.” We now know that children with autism perceive, experience, and respond to the world very differently than children without autism. Experiences that may be tolerable for most typical children might be frightening, disturbing, or irritating for a child with ASD. Children with autism may also be unresponsive to other experiences (e.g., insensitive to pain), may not show stranger or separation anxiety, and may be seemingly unaware of obvious dangers (e.g., running into traffic).
Previous research examining the types and frequencies of fears in children with autism have found odd and intense fears in approximately 40% of children with autism, whereas unusual fears were present in only 0–5% of children without autism, including children with a learning disability, language disorder, ADHD, intellectual disability, and typical development. Studies also indicate that while some of the most common fears for children with autism and typical development overlap, children with autism have frequent fears that were not amongst the most frequently reported for typical children. These include fear of thunderstorms, large crowds, and closed spaces.
A large scale study reported in Research in Autism Spectrum Disorders investigated unusual fears in a sample of 1033 children ages 1-16 with autism. The purpose of the study was to categorize and determine specific types of unusual fears in children with autism as well as identify variables related to the presence or absence of these fears. Unusual fears were reported in 421 (40.8%) of the 1033 children with autism. A total of 487 unusual fears were reported, representing 92 different fears. The most common unusual fear was fear of toilets, accounting for 11.7% of the unusual fears. For children with unusual fears, 60.0% had one fear, 27.6% had two, 10.2% had three, 1.9% had four, and one child had five fears. Unusual fears fell into 14 categories. More than half of the 421 children with unusual fears had fears of mechanical things, heights, and/or weather. The most common category was fear of mechanical things, which accounted for 23.8% of the types of fears reported. For children with unusual fears, 71.1% had fears in only one category, 21.9% in two categories, 6.7% in three categories, and 0.3% in four categories. Many children also had common childhood fears and phobias (including fear of dogs, bugs, spiders, snakes, the dark, doctors, barbers, monsters, people in costumes, mechanical toys, sleeping alone, fire, and swimming), which increased the overall proportion of children with autism who had intense fears and phobias to more than 50%.
Categories and Frequency of Unusual Fears
The most frequently reported categories of unusual fears were:
Mechanical things (Blenders, can openers, cassette players, ceiling fans, clothes, dryers, drills, electric toothbrushes, exhaust fans, hair dryers, hand dryers, leaf blowers, toilets, vacuum cleaners, washing machines, water fountains, wheelchairs, windshield wipers)
Heights (Elevators, escalators, heights, steps)
Weather (Cloudy weather, natural disasters such as floods, droughts, hurricanes, tornadoes), rain, thunderstorms, wind)
Non-mechanical things (Balloons, black television screen, buttons, clam shells, crayons, dolls, drains, electrical outlets, eyes on toys garden hose, glass tabletops, glow in dark stars, gum under table, hair in bathtub, lights, mole on person’s face, moon, shadows, strings, stuffed animals, swinging or rocking things, tall things, things on ceiling, vent on house)
Places (Bathroom, bedroom, certain house or restaurant, closed or small spaces, garage, large or open space, room with doors unlocked or open)
Worries Dying (e.g., bone breaking through chest, car accident, drowned, eaten by fleas, heart attack, murdered, natural disaster, poisoned, spleen exploding, world ending), germs or contamination, running out of certain foods, running out of gas, something falling over, swallowing something when did not, toilet overflowing, tree falling on house)
Visual media (Characters in or segments of movies, television shows, commercials, computer games)
Types and Frequency of Unusual Fears
Unusual fears reported by parents fell into two categories: (1) uncommon fears not typically reported in children in the general population or in children with specific phobias and (2) fears that have been reported in studies of children without autism but which were considered unusual by parents because of their intensity, obsessiveness, irrationality, or interference with functioning. Of the total number reported, the most common unusual fears in three or more children with autism were:
Worry dying (e.g., bone breaking through chest, car accident, drowned, eaten by fleas, heart attack, murdered, natural disaster, poisoned, sick, spleen exploding, or world ending)
Visual media (characters in or segments of movies, television shows, commercials, or computer games)
Children with and without unusual fears did not differ in age, IQ level, mental age, autism severity, race or parent occupation. Of all the demographic variables, only female gender was associated with the presence or absence of unusual fears. More girls had unusual fears (48.8%) than did boys (39.1%). This is consistent with the earlier studies indicating that girls with autism had more fears than boys and with general population studies showing that girls had more fears and higher fear survey scores than boys. The finding that children with and without unusual fears did not differ in age suggests that unlike most typical children, those with autism may not outgrow unusual fears. Likewise, the findings regarding autism severity and parent occupation suggest that the presence of unusual and intense fears may be present across SES and the entire autism spectrum. The authors note that the lack of demographic differences in the study may suggest a neurobiological basis for fears overriding developmental and environmental influences.
Conclusion and Implications
Research suggests that it is critical to assess for unusual and intense fears in children with ASD because they are common in this population and can interfere significantly with functioning. Specific fears and phobias have been cited as frequent anxiety triggers/stressors for children with ASD. The impact of anxiety includes personal distress in children, parents, and siblings, increase in challenging behavior and stereotyped behaviors, restriction of activities/opportunities and negative impact on quality of life for child and family. For example, children with autism may avoid necessary life situations (e.g., refusing to go to school because there may be a fire drill) or be in a constant state of anxiety and unable to function optimally because of their fears.
Identification of specific fears and phobias in children with ASD can help educators and interventionists improve programs and services for this group of students. This information may be especially useful for clinicians, particularly those utilizing CBT as a treatment approach for children and youth with ASD. There is evidence to suggest that the interventions used to treat intense fears and phobias in children without autism (exposure, desensitization, modeling, shaping, and reinforcement) might also be effective for children who have autism. Lastly, further research is needed to investigate why some specific unusual fears are common to autism but not the general population. As more individuals with ASD communicate about their fears and reasons for their idiosyncrasies, we may come to a better understanding of autism and its symptoms.