Researchers at the Queensland Brain Institute have discovered a relationship between autism spectrum disorder (ASD) and post-traumatic stress disorder (PTSD) in mouse models. Dr. Shaam Al Abed and Dr. Nathalie Dehorter found that a mild stress can trigger PTSD in individuals with ASD, resulting in worsened core autism traits when traumatic memories are formed. While previous studies have noted the co-occurrence of ASD and PTSD in humans, the underlying connection between the two disorders has not been well understood. The researchers aimed to investigate the predisposition to PTSD in ASD and the neurobiological mechanisms involved.
ASD and PTSD both display similarities such as impaired emotional regulation, altered memory function, and difficulties with fear conditioning. The researchers conducted experiments on four mouse models of ASD, finding that a single mild stress could lead to the formation of traumatic memories. In contrast, extreme stress triggers PTSD in individuals without ASD. This unique perception of stress in ASD was of interest to the researchers, as it contributes to the development of PTSD. The study sheds light on how the formation of traumatic memories exacerbates the social and behavioral challenges faced by individuals with ASD.
The prefrontal cortex, a specialized region in the brain responsible for social cognition and behavior, was identified as a key player in both ASD and PTSD. Dysfunction in the prefrontal cortex has been linked to both disorders, and specific alterations in cortical circuits were found to lead to the formation of PTSD-like memories during stress. Interneurons in the prefrontal cortex, crucial for fear memorization and sensory function, were also identified as playing a role in stress-related disorders. ASD alters the response of interneurons to stress, further worsening autism traits following the formation of traumatic memories.
The researchers were surprised to find that forming traumatic memories could exacerbate social and behavioral challenges in individuals with ASD. However, successful recontextualization of traumatic memories through behavioral therapy led to a significant improvement in ASD traits that were worsened by stress. This discovery highlights the close connection between ASD and PTSD and suggests a potential shift in the way clinicians approach stress management in individuals with ASD. Understanding the predisposition to PTSD in ASD and the effectiveness of behavioral therapy in treating it could have significant implications for patient care. The results of this study were published in the journal iScience.
Overall, the study conducted by the Queensland Brain Institute researchers demonstrates a reciprocal relationship between ASD and PTSD, showing how mild stress can trigger PTSD in individuals with ASD and worsen core autism traits. The involvement of the prefrontal cortex and altered interneuron function in the formation of traumatic memories sheds light on the underlying mechanisms of this relationship. The findings suggest a promising avenue for improving ASD traits through behavioral therapy that recontextualizes traumatic memories. This research could potentially reshape the approach to managing stress and addressing PTSD predisposition in individuals with ASD.