This study looked at 116 adults diagnosed with ADHD at a specialised adult ADHD outpatient clinic in The Hague, Netherlands. Most were men (72 of 116, 62.1%), and the average age was 32 years. Each person filled in questionnaires about their sensory experiences and about autistic traits.
Compared with general population norms, the ADHD group tended to miss or under-notice sensory input more (a low registration score of 36.2 against 30.3) and to be more easily bothered by sensory input (a sensitivity score of 40.9 against 33.7). Both differences were very unlikely to be chance.
About 1 in 5 were classed as under-sensitive (19.0%) and about 1 in 5 as over-sensitive (20.7%), against only 2% in the norm group. These patterns were more common in women, with 43% of women affected against 22% of men.
The more severe a person's ADHD symptoms were, the more likely they were to show these sensory patterns. This link held even after accounting for autistic traits, though the autism trait score was higher in the ADHD group (23.0 against 16.4).
This was a one-time self-report survey with a fairly small sample and a 68% response rate. Only 4 people had an autism diagnosis, too few for firm conclusions.
Source: Bijlenga D, Tjon-Ka-Jie J, Schuijers F, et al.. Atypical sensory profiles as core features of adult ADHD, irrespective of autistic symptoms. European Psychiatry (2017). doi:10.1016/j.eurpsy.2017.02.481