Abstract
Autistic adults without a suspected intellectual disability reported several motor features such as having tremors, and stiffness in one's legs which are considered to be part of a complex of motor features called parkinsonism. This so-called parkinsonism was remarkably prevalent in middle-aged and older autistic adults in two independent studies (Dutch study: 50-81 years, 183 males, 113 females, all adulthood diagnoses; the USA study: 50-83 years, 110 females, 109 males, majority adulthood diagnosis). Parkinsonism can be part of the progressive motor disease-Parkinson's disease. Therefore, it is important that future studies, including in-person neurological assessment, determine if (and if so, why) autistic adults who report these motor features are at increased risk for developing Parkinson's disease.