Grant: Project Grant

While autistic individuals experience impairments in everyday functioning that often impede the transition to independence during late adolescence/early adulthood, some individuals are affected more than others. The biological mechanisms contributing to why some individuals experience more impairment than others remain poorly understood. Autism is present from early development when the brain is rapidly building and refining connections between cells. It is hypothesized that in autistic individuals these critical processes are disrupted, which could contribute to autism-associated impairments. Recently, a radioactive dye ([18F]SynVesT-1) was developed that can quantify brain cell connections in humans using positron emission tomography (PET). Initial studies in individuals with mental health disorders have found links between altered brain cell connections and mental health related impairment. No study has yet measured brain cell connections using this novel tool in autistic individuals. We will study whether autistic youth/young adults have altered brain cell connections compared to individuals without any psychiatric/medical diagnosis and whether impairments in thinking abilities and everyday functioning are related to alterations in brain cell connections. We will also explore whether a novel MRI tool (Neurite Orientation Dispersion and Density Imaging) is related to the PET marker of brain cell connections that we are studying here. As PET is costly and not available across clinical centres, the potential to use an MRI-derived marker in place of a PET scan to measure brain cell connections would enable future studies of brain cell connections in larger and more diverse samples. To date, it is not clear why impairment varies considerably across autistic individuals. The current study may yield a marker to help explain this variability, and in turn support development of novel approaches aimed to support autistic individuals with more severe impairments.