Sensory issues in adult ADHD controlling for autistic symptoms...

I was intrigued to read the paper by Bijlenga and colleagues [1] reporting on "the prevalence of sensory hyper- and hyposensitivity among adults with ADHD [attention-deficit hyperactivity disorder], controlling for autistic symptoms."

The authors concluded that among their cohort of over 100 adults diagnosed with ADHD, both sensory hyper- and hyposensitivity symptoms as described by response to the Adolescent/Adult Sensory Profile-NL (AASP-NL), were over-represented compared with population norm data. Interestingly, authors also took a snapshot of 'autistic symptoms' based on responses to the Autism-spectrum Quotient (AQ) and reported that: "Adults with ADHD had more autistic symptoms" but: "Sensory hypo- and hypersensitivity were both related to an increased ADHD score, even showing a dose-response relationship, but not to any autistic symptom or comorbid disorder."

My intrigue stems from a few implications of such findings, with the requirement for much more study. First is the quite important overlap between autism and ADHD (see here) confirmed symptom-wise in the Bijlenga paper. Second is the idea that, within this cohort at least, adults with ADHD may variably present with sensory issues. Third, assuming that the AQ 'does what it says on the tin' with regards to screening for autistic symptoms (see here), the lack of a notable connection between autistic symptoms and sensory sensitivities in the context of adult ADHD might have some important implications related to my first point when autism and ADHD appear simultaneously. Indeed it poses the question: are sensory issues, now noted in specific relation to autism via at least one diagnostic schedule (see here) actually 'a core part of all autism' or perhaps a feature of something else for some?

Reiterating that more research is required (not least more formal screening for autism over and above the use of AQ or related screening schedules) that last point/question might actually make more sense than many people might first realise. If, for example, we take the view that autism rarely exists in some sort of diagnostic vacuum (see here and see here) and that science and clinical practice really needs to be more proactive when it comes to an autism diagnosis being a starting point not the finishing line (see here), it's not beyond the realms of possibility that sensory issues for some might have been spuriously linked to autism when in fact other comorbid labels/symptoms better account for their presentation. This not only has implications for screening/diagnosis but also management of said sensory symptoms, as per other reports talking about the use of stimulant medication indicated for ADHD 'affecting' aspects of odour sensitivities for example [2]. By saying that I'm not making any sweeping judgements about pharmacotherapy for ADHD treating sensory issues present alongside autism, merely that new avenues might open up.

A final quick glance at some of the other peer-reviewed literature on the topic of sensory issues and ADHD reveals that there is some history in this area [3]. Said sensory issues have also been *linked* to some of the other behavioural facets noted in cases of ADHD [4]. Perhaps, in light of such data, it is time for ADHD - whether in symptoms or in label - to be taken into account when sensory issues are discussed in the context of autism in the science literature and in clinical practice?

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[1] Bijlenga D. et al. Atypical sensory profiles as core features of adult ADHD, irrespective of autistic symptoms. Eur Psychiatry. 2017 Feb 21;43:51-57.

[2] Romanos M. et al. Improved odor sensitivity in attention-deficit/hyperactivity disorder. Biol Psychiatry. 2008 Dec 1;64(11):938-40.

[3] Clince M. et al. Comparing and Exploring the Sensory Processing Patterns of Higher Education Students With Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder. Am J Occup Ther. 2016 Mar-Apr;70(2):7002250010p1-9.

[4] Shimizu VT. et al. Sensory processing abilities of children with ADHD. Braz J Phys Ther. 2014 Jul-Aug;18(4):343-52.

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Bijlenga D, Tjon-Ka-Jie JY, Schuijers F, & Kooij JJ (2017). Atypical sensory profiles as core features of adult ADHD, irrespective of autistic symptoms. European psychiatry : the journal of the Association of European Psychiatrists, 43, 51-57 PMID: 28371743