Wednesday, 3 December 2014

Autism + ADHD equals greater risk of psychiatric comorbidity?

Because the name Mu-Hong Chen (and colleagues) has appeared so, so many times on this blog with reference to the various studies originating from investigations of the Taiwan National Health Insurance Research Database, I genuinely did have to make sure that I hadn't covered one of their recent papers [1] on here previously. Actually I can't 100% confirm that I haven't already covered a further addition to their research repertoire which concluded that: "Patients with ADHD [attention deficit hyperactivity disorder] + ASD [autism spectrum disorder] were associated with the greatest risk of having comorbid bipolar disorder, depressive disorder, anxiety disorder, disruptive behavior disorder, and tic disorder" over and above various control groups. So, if this does happen to be a duplicate post, I apologise in advance.
It's just... none of us have ever been aboard a submarine before

ADHD and ASD appearing together in the same person has been the source of quite a bit of discussion in [some] autism research circles in recent years. Whether it be with the frequency figures in mind (see here) or some rather interesting suggestions about ESSENCE (see here) or autism plus [2] if you prefer, it seems the notion of autism - quite a lot of autism - being a stand-alone condition existing in some sort of diagnostic vacuum is gradually falling by the wayside. The more contemporary view is that clinical presentation (i.e. real life) is rather more fuzzy and complicated than we've all been led to believe. A shocker I know.

The further suggestion from Chen et al that: "A comprehensive interview scrutinizing the psychiatric comorbidities would be suggested when encountering and following patients with both ASD and ADHD in clinical practice" is perhaps quite obviously implied from their findings. Said findings based on the study of: "725 patients with ASD-alone, 5694 with ADHD-alone, 466 with ASD + ADHD, and 27,540 (1:4) age-/gender-matched controls". Sample size and power, as you might realise, was probably not a great issue for this study.

What's more to say about these findings? Well, when we talk about 'the common ground' between conditions like autism, ADHD, schizophrenia, depression, etc. the Chen findings provide some exquisite evidence to back-up the assertion of common genetic findings potentially weaving their way through various presentations. That being said, I'm not necessarily saying that genes, mutations on genes, are the be-all-and-end-all when it comes to deciphering reasons for such common ground, given the often important variable of 'environment' (however you wish to describe this) and those all-important gene x environment interactions. Just as an aside I'll refer you to some of my other musings when it comes, for example, to how infection or response to infection might show interplay (see here and see here) and even a possible effect from those trillions of wee beasties which we call carry with us (see here). It's likely to be complicated and multi-factorial.

The Chen findings might also be viewed as further evidence for a revision to the way we classify when it comes to psychiatry and behaviour too. Followers of the whole RDoC debate (see here) can probably see how starting from a different point when it comes labelling conditions might allow for some more revealing aspects of the underlying genetics/biochemistry/brain and other organ stuff to come to the forefront.

And just in case you hadn't had your fill of research from Taiwan based on that Taiwan National Health Insurance Research Database, yet more big data findings: (i) ADHD does indeed seem to be "associated positively with asthma" [3], and (ii) "A predisposition for allergies was an independent risk factor for hypertension, dyslipidemia, and diabetes mellitus among patients with schizophrenia or bipolar disorder" [4].

I'm just wondering who would be brave enough to write the book: The Taiwan National Health Insurance Research Database: research findings 1995 to present day...

Music, music, music... How about Neneh Cherry and Manchild?


[1] Chen M-H. et al. Autistic spectrum disorder, attention deficit hyperactivity disorder, and psychiatric comorbidities: A nationwide study. Research in Autism Spectrum Disorders. 2015; 10: 1-6.

[2] Gillberg C. & Fernell E. Autism plus versus autism pure. J Autism Dev Disord. 2014 Dec;44(12):3274-6.

[3] Chou CJ. et al. Asthma in patients with attention-deficit/hyperactivity disorder: A nationwide population-based study. Ann Clin Psychiatry. 2014 Nov;26(4):254-260.

[4] Chen MH. et al. A predisposition for allergies predicts subsequent hypertension, dyslipidemia, and diabetes mellitus among patients with schizophrenia or bipolar disorder: a nationwide longitudinal study. Schizophr Res. 2014 Oct;159(1):171-5.

---------- Chen, M., Wei, H., Chen, L., Su, T., Bai, Y., Hsu, J., Huang, K., Chang, W., Chen, T., & Chen, Y. (2015). Autistic spectrum disorder, attention deficit hyperactivity disorder, and psychiatric comorbidities: A nationwide study Research in Autism Spectrum Disorders, 10, 1-6 DOI: 10.1016/j.rasd.2014.10.014