ASD is a neurodevelopmental condition that affects communication, behavior, and sensory processing. Parkinson’s disease, by contrast, is a progressive neurodegenerative disorder that primarily affects motor functions due to the deterioration of dopamine-producing neurons
People with autism spectrum disorder (ASD) may face a significantly higher risk of developing Parkinson’s disease earlier in life, according to a major new study that reveals possible shared biological mechanisms between the two neurological conditions.
Published in JAMA Neurology, the study was led by researchers at the Karolinska Institutet in Sweden, who found that individuals diagnosed with autism were four times more likely to develop Parkinson’s disease than those without autism. This risk remained elevated even after accounting for variables such as genetic predisposition, socioeconomic background, and co-existing mental health conditions.
“This indicates that there can be shared biological drivers behind ASD and Parkinson’s disease,” said Weiyao Yin, a researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet. “One hypothesis is that the brain’s dopamine system is affected in both cases, since the neurotransmitter dopamine plays an important part in social behavior and motion control.”
ASD is a neurodevelopmental condition that affects communication, behavior, and sensory processing. Parkinson’s disease, by contrast, is a progressive neurodegenerative disorder that primarily affects motor functions due to the deterioration of dopamine-producing neurons. While the two conditions may appear clinically distinct, this new evidence suggests they might share overlapping neurobiological pathways, particularly involving dopamine signaling.
The study analyzed Swedish national registry data from more than two million individuals born between 1974 and 1999. Researchers followed the cohort from the age of 20 through the end of 2022. Over the course of the study, individuals with autism were found to be at significantly higher risk for early-onset Parkinson’s, typically defined as developing before age 50.
What makes the findings especially notable is that the association between ASD and Parkinson’s remained strong even when adjusting for potential confounding factors such as mental health history, use of psychiatric medications, and family history of neurodegenerative disease.
Although Parkinson’s is most commonly associated with aging, early-onset forms of the disease are increasingly being studied for their genetic and developmental origins. This study provides new evidence that ASD, which is typically diagnosed in early childhood, could be a risk marker for neurodegeneration later in life.nPrevious research has hinted at the role of dopamine dysfunction in both autism and Parkinson’s disease. While Parkinson’s is directly linked to the loss of dopamine-producing neurons in the brain’s substantia nigra, studies suggest that individuals with ASD may also experience abnormalities in dopamine signaling, though the mechanisms are less clearly understood.
“We hope that our results will eventually help to bring greater clarity to the underlying causes of both ASD and Parkinson’s disease,” Yin said, emphasizing the need for continued research into this potential biological link. The findings also carry important implications for healthcare services. People with autism often face multiple health challenges, including high rates of psychiatric comorbidities, use of psychotropic medications, and barriers to accessing consistent medical care. The researchers called for long-term monitoring of individuals with ASD to better detect and manage emerging neurological symptoms.
“This is a vulnerable group,” Yin added. “Given their high healthcare needs and the possibility of elevated risk for conditions like Parkinson’s, more focused surveillance and early intervention strategies may be warranted.”
As the global burden of both autism and Parkinson’s disease continues to rise, understanding their possible connection could open new avenues for early diagnosis, personalized care, and targeted therapies—benefiting two historically underserved populations in the process.
