A Preliminary Investigation of Dopamine Transporter Binding Abnormalities in Individuals With Autism Spectrum Disorder.

In the emerging literature on aging and autism, a consistently replicated finding is a significantly increased risk for Parkinson's disease (PD), up to six times higher. Also, atypical dopamine activity has been observed in autistic individuals and animal models. The only FDA-approved medications for ASD are the atypical antipsychotic medications, which inhibit postsynaptic dopaminergic and serotonergic transmission to treat irritability. Studies using resting state functional magnetic resonance imaging (rsfMRI) show disruption in striatal circuits in ASD. However, no studies have examined the striatal PD biomarker with dopamine transporter (DaT) single photon emission computed tomography (SPECT) imaging in adults with ASD. In this pilot study, we aimed to evaluate DaT SPECT in 18-24-year-old individuals with ASD and perform a pilot investigation of functional connectivity (FC) between the striatum and other brain areas. Four of the 12 participants had definite abnormalities or possible abnormalities in striatal DaT uptake. Participants were then separated into abnormal and normal DaT groups. In the exploratory analysis, the abnormal DaT group showed greater striatal FC to the paracingulate region compared with the normal DaT group. These pilot findings should be cautiously interpreted. Larger studies are needed to explore their link to behavioral outcomes and potential in predicting treatment responses. Examining how these findings evolve with age is also crucial, given evidence of the heightened risk of PD in ASD.