Autistic people may be at greater risk of developing this serious illness as they age.

As more and more people with autism spectrum disorders reach middle age, the link with a disease that is more common in older people is beginning to raise questions among researchers.

Autism affects 1 in 100 people worldwide, as it does in France. Autism spectrum disorders (ASD) are often associated with other health problems, such as sleep and developmental disorders, depression, anxiety, and epilepsy. However, several recent studies suggest that people affected by autism may also have an increased risk of suffering from another condition later in life.

The most recent study on the subject was conducted by the renowned Karolinska Institutet and was published in the journal JAMA Neurology in May 2025. The researchers analyzed the health data of more than 2 million Swedes, who were tracked for many years. They observed that people who had been diagnosed with autism were at greater risk of developing Parkinson's disease as they aged.

The risk was multiplied by four compared to people who had not been diagnosed with autism. This risk was still increased when taking into account various factors such as genetic predispositions or medication use, since certain treatments prescribed for autism "can cause symptoms similar to those of Parkinson's disease," the Karolinska Institute stated in a press release.

The study authors believe that "the two diseases may share underlying biological mechanisms." According to Dr. Weiyao Yin, lead author of the study, "Common biological factors may underlie ASD and Parkinson's disease. One hypothesis is that the brain's dopamine system is affected in both cases, as the neurotransmitter dopamine plays an important role in social behavior and movement control."

Further research will be needed to confirm and clarify these findings, especially since the study only analyzed cases of "early-onset Parkinson's, before the age of 50." Several other studies have shown that people with autism spectrum disorder are significantly more likely to suffer from Parkinsonism, the characteristic symptoms of Parkinson's disease (tremors, slowness of movement, rigidity, etc.).