Evidence indicates both disorders co-occur with a high frequency, in 20-50% of children with ADHD meeting criteria for ASD and in 30-80% of ASD children meeting criteria for ADHD.
Also in the past, at least in US with DSM-4 it was thought that ASD and ADHD are mutually exclusive, so there’s probably a lot of people incorrectly missing that diagnosis.
If the source is to be trusted:
https://pubmed.ncbi.nlm.nih.gov/20148275/
Also in the past, at least in US with DSM-4 it was thought that ASD and ADHD are mutually exclusive, so there’s probably a lot of people incorrectly missing that diagnosis.
DSM-5 superseded that in May 2013.