Toward better characterization of restricted and unusual interests in youth with autism

Despite their high prevalence and clinical importance in autism, unusual and restricted interests remain under-researched and poorly understood. This study aimed to characterize the frequency and type of interests in autism by coding caregivers’ open-ended responses in a sample of 237 autistic children and adolescents ( M age = 8.27 years, SD age = 4.07; range: 2.08–18.25 years). It further aimed to explore the effects of age, sex, cognitive functioning and social and communication deficits on the number and type of interests. We found that 75% of autistic youth had at least one interest and that 50% of those children showed two or more different interests. The most frequent interests were sensory-based (43%), with a majority of these interests relating to the visual modality. Interest within vehicles/transportation, fictional characters, television/digital versatile disk/movies, computers, and video games, constructive, mechanical objects, animals and plants, and attachment to specific objects were also prevalent. Logistic regression showed that being male, having a co-occurring intellectual disability and having more severe social and communication impairments were associated with a higher probability of having one or more restricted interests. Sex was significantly associated with the type (χ 2 = 37.52, Phi = 0.37, p = 0.021) of restricted interests, with females showing a significantly higher percentage of creative interests and males significantly higher percentage of interest in characters, vehicles/transportation, computers/video games, mechanical objects and constructive interests. Theoretical and measurement implications are discussed. Lay abstract Despite being highly prevalent among people with autism, restricted and unusual interests remain under-researched and poorly understood. This article confirms that restricted interests are very frequent and varied among children and adolescents with autism. It also further extends current knowledge in this area by characterizing the relationship between the presence, number, and type of restricted interests with chronological age, sex, cognitive functioning, and social and communication symptoms.