The neurobiology of fear: understanding anxiety in autism spectrum disorder

Although anxiety is not considered a core feature of autism spectrum disorder (ASD), it adds a significant and distinct layer of complexity. While not included in the diagnostic criteria, anxiety disorders, including obsessive-compulsive disorder, are highly prevalent among individuals with ASD. Many exhibit clinically elevated levels of anxiety, which can exacerbate social, cognitive, and emotional challenges. Individuals with heightened anxiety are more prone to sustained negative emotional states, potentially reflecting dysfunction in brain systems involved in emotion regulation. Anxiety is widely understood to have a neurobiological basis, and extensive research has examined how its arousal influences behavioral development, particularly in neurotypical populations. This paper explores the neurodevelopmental underpinnings of anxiety within the context of ASD, with a focus on the amygdala, a structure heavily implicated in both anxiety and autism. We review the role of the prefrontal cortex in modulating amygdala function, and how atypical connectivity between these regions may contribute to the manifestation of anxiety symptoms in individuals with ASD.