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

Researchers used brain scans to look at dopamine (a brain chemical) in 12 young adults with autism. They found that 4 people had differences in how their brains processed dopamine. This is important because people with autism have a much higher chance of developing Parkinson's disease later in life. The study was very small, so the results need to be confirmed with larger studies before we can understand what this means.

This pilot study investigated dopamine transporter (DaT) binding in 12 young adults with autism spectrum disorder (aged 18-24) using SPECT imaging. Four participants showed definite or possible abnormalities in striatal DaT uptake. Those with abnormal DaT showed greater functional connectivity between the striatum and paracingulate region compared to those with normal DaT. The research was motivated by findings that autistic individuals have up to six times higher risk of Parkinson's disease and known dopamine system abnormalities in autism.

The authors emphasize these preliminary findings require cautious interpretation and larger studies are needed to explore links to behavioral outcomes and treatment prediction.

Findings suggest potential neurobiological markers that may help identify autistic individuals at risk for movement disorders. However, given the preliminary nature, clinical application is not yet appropriate. Larger studies needed to establish reliability and clinical utility before implementation.

Very small sample size (n=12), pilot study design, age range limited to 18-24 years, no behavioral outcome measures, exploratory analysis only, and authors explicitly state findings require cautious interpretation.

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.