Self-reported parkinsonism features in older autistic adults: A descriptive study.

Parkinsonism was assessed with a self-report questionnaire, not a neurological examination, so positive screens cannot be treated as diagnoses. The PSQ is a new instrument and its validation results had not been replicated in this paper. ASD diagnoses were self-reported clinical diagnoses and were not confirmed with standardized autism assessment tools. The paper did not follow participants over time, so it cannot show whether these features progress to Parkinson disease or are part of autism. Age of onset was retrospectively self-reported in the Dutch sample and may be unreliable. Current antipsychotic use was assessed only at the time of the survey, not across the lifespan. Only 22.8% of the Dutch sample and 22.5% of the US sample were over 65, although the 2.6% comparison estimate was for parkinsonism in people over 65. The two samples were recruited for separate studies and differed in measures and participant characteristics, so differences in positive screens may not be directly comparable. The study excluded people with suspected intellectual disability, so it does not address that group.

The Dutch study was funded by the Netherlands Organisation for Scientific Research and the Netherlands Institute for Advanced Study. The US study was funded by George Washington University. One author received funding from an Autism Speaks Postdoctoral Fellowship. No other conflicts of interest are stated.

Do not read the 16.9% and 33% positive screens as Parkinson disease diagnoses. They came from a self-report questionnaire, and the mean weighted screening scores were 1.9 and 4.0, below the Parkinson disease group mean of 12.8.