Self-injurious behaviors with increased likelihood of injury in autistic youth: The role of distress linked to a strong preference for sameness

Self-injurious behaviors in autistic youth vary widely in their form, intensity, and potential for physical injury. This study explored predictors of two categories of self-injurious behaviors that were delineated based on their potential for physical injury (self-injurious behavior-High Likelihood and self-injurious behavior-Low Likelihood), with a focus on the role of distress linked to a strong preference for routines (otherwise known as insistence on sameness). The sample included 1892 autistic youth (M age = 10.82, SD age = 4.14; 22% females) across the United States. Distress associated with insistence on sameness was the strongest predictor of total self-injurious behavior scores, self-injurious behavior-Low Likelihood, and self-injurious behavior-High Likelihood, after controlling for demographic factors and speech level, and remained a unique predictor after accounting for variance explained by other restricted and repetitive behaviors. Sensory hypersensitivity and sensory-seeking were strong unique predictors of all self-injurious behaviors, while hyposensitivity was a weaker predictor of self-injurious behavior total and self-injurious behavior-Low Likelihood, and a non-significant predictor of self-injurious behavior-High Likelihood. Among demographic factors, lower household income was the strongest predictor of all self-injurious behaviors. Higher speech level was a positive predictor of self-injurious behavior-Low Likelihood but a negative predictor of self-injurious behavior-High Likelihood. These findings demonstrate the role of distress associated with insistence on sameness in manifestations of self-injurious behaviors and highlight the importance of exploring predictors at a more granular level to inform targeted interventions and support. Lay Abstract This study explored factors associated with repetitive self-injurious behaviors in autistic youth, focusing on emotional distress linked to a strong preference for routines (often referred to as insistence on sameness), a category of behaviors that includes difficulties with change and a strong preference for routines and/or rituals. We examined two categories of self-injurious behaviors: lower likelihood of physical injury (self-injurious behavior-Low Likelihood) and higher likelihood of physical injury (self-injurious behavior-High Likelihood). The study included 1892 autistic youth of varying ages and cognitive abilities. The main finding was that distress associated with disruptions to routines was the strongest predictor of all types of self-injurious behavior. Youth with greater sensitivity to sensory input or sensory-seeking behaviors were more likely to engage in self-injurious behaviors that could increase risk of physical injury. In contrast, those with reduced sensitivity to sensory input were less likely to engage in self-injurious behaviors. Demographic factors also played a role in the manifestation and severity of self-injurious behaviors. Lower household income was strongly associated with greater self-injurious behavior severity. In addition, higher speech production (e.g. speaking in full sentences) was associated with greater severity of self-injurious behavior-Low Likelihood and self-injurious behavior-High Likelihood. These findings highlight the complexity of self-injurious behaviors in autistic youth and the importance of understanding the different factors that contribute to these behaviors. This study may help to contribute to the development of more responsive, tailored interventions for self-injurious behaviors among autistic youth.