Saturday, 21 October 2017

"we found no association between maternal folic acid supplementation and offspring ASD" but...

The findings reported by Marit Strøm and colleagues [1] observing "no association between maternal folic acid supplementation and offspring ASD [autism spectrum disorder]" throw yet another research 'spanner in the works' when it comes to the [very generalised] idea that pregnancy folic acid supplementation might affect risk of offspring autism.

Don't get me wrong, I appreciate all the data suggesting that folic acid supplementation during pregnancy is a useful thing for helping to reduce the risks of neural tube defects (NTDs) for example. But when it comes to pregnancy folic acid (folate) potentially impacting on offspring risk of autism, I've always been a little cautious of the collected data so far and how its been interpreted/generalised in certain quarters (see here and see here for examples).

So, drawing on data from the "entire DNBC [Danish National Birth Cohort]" initially including nearly 100,000 singleton, live born children, researchers set out to find female "users" of folic acid supplements either just before conception or during the earliest stages of their pregnancy. Not just content with folic acid, they also looked at available data on "periconceptional vitamin B12" use too on the basis of some connection between the two vitamins. They then searched connected databases to find those offspring with a diagnosis of autism spectrum disorder (ASD): "identified by International Classification of Diseases (ICD)-10 diagnosis codes F840, F841, F845, F848, and F849; ‘childhood autism’ by diagnosis code F840." Analyses of these collected variables were undertaken, as well as adjusting for potentially confounding variables such as maternal age, parity, education level and the like.

Results: well, as per the title of this post, researchers reported finding very little when it came to pre-pregnancy or early pregnancy folate use: "There was no detectable association between maternal folic acid supplementation in the periconceptional period and offspring ASD" and: "Results from the analyses using midpregnancy exposure data were similar: there was no association with ASD/childhood autism neither for folic acid supplementation nor for dietary folate intake." Such results held when various 'corrections' were made for variables such as "sex specific effects" and cases where intellectual (learning) disability was present for example.

I have to say that the authors do seem genuinely surprised that their results did not tally with other large, population studies on this topic: "At present we are not able to present any viable explanation for these discrepant results." They do mention one particularly important point insofar as the usefulness of looking at small changes to something called the methylenetetrahydrofolate reductase (MTHFR) gene in the context of autism and folic acid as other authors have done [2]. This, on the basis that MTHFR plays an important role in folate metabolism (see here) and issues with this gene are no stranger to the autism research landscape (see here). I'm also minded to refer readers back to another potentially important issue identified in relation to some autism that might also affect folate metabolism: folate receptor autoantibodies (FRAAs) (see here).

I still think there is a place for further investigations on folic acid use during pregnancy and offspring autism risk. But like many things in the context of the plural 'autisms' (see here), it perhaps makes more sense to zoom in on potentially relevant sub-groups on the autism spectrum rather than treating all autism as being homogeneous in either aetiology or presentation. I might add that folic acid use as part of wider range of nutritional supplements potentially used during early pregnancy remains an important area of research attention in the context of offspring autism [3].

And also just to complicate things even further, the results from Wang and colleagues [4] add: "this comprehensive meta-analysis suggested that maternal use of folic acid supplements during pregnancy could significantly reduce the risk of ASD in children regardless of ethnicity, as compared to those women who did not supplement with folic acid." I don't think the debate is finished yet on this topic.

Music to close, and since my brood and I are competing again today, Sia (again) and some brilliant kata (hopefully our Heian Sandan will be as good).

----------

[1] Strøm M. et al. Research Letter: Folic acid supplementation and intake of folate in pregnancy in relation to offspring risk of autism spectrum disorder. Psychol Med. 2017 Sep 26:1-7.

[2] Schmidt RJ. et al. Maternal periconceptional folic acid intake and risk of autism spectrum disorders and developmental delay in the CHARGE (CHildhood Autism Risks from Genetics and Environment) case-control study. Am J Clin Nutr. 2012 Jul;96(1):80-9.

[3] DeVilbiss EA. et al. Antenatal nutritional supplementation and autism spectrum disorders in the Stockholm youth cohort: population based cohort study. BMJ 2017; 359: j4273.

[4] Wang M. et al. The association between maternal use of folic acid supplements during pregnancy and risk of autism spectrum disorders in children: a meta-analysis. Molecular Autism. 2017; 8: 51.

----------

Friday, 20 October 2017

Completing the set: features of ADHD in childhood epilepsy

'Completing the set' used in the title of this post refers to the idea that a diagnosis of epilepsy rarely(?) seems to exist in some sort of diagnostic vacuum as per previous discussions whereby features of autism (see here) and dyspraxia / developmental coordination disorder (DCD) (see here) seem to be over-represented in cases of epilepsy.

This time around the focus was on attention-deficit hyperactivity disorder (ADHD) and the findings reported by Isabell Brikell and colleagues [1] suggesting that: "Individuals with epilepsy had a statistically significant increased risk of ADHD." Researchers arrived at their conclusions on the basis of examining some of those wonderful Scandinavian population registries that are providing all-manner of interesting details on possible trends and patterns in various areas: "We identified 1,899,654 individuals born between 1987 and 2006 via national Swedish registers..." Said data were actually used to look at "the familial coaggregation of epilepsy and ADHD and to estimate the contribution of genetic and environmental risk factors to their co-occurrence" but also served the purpose of looking at ADHD prevalence alongside epilepsy. Indeed it was also interesting to note the authors' conclusions about familial liability to the "cross-disorder overlap": "The genetic correlation was 0.21 (95% CI = 0.02-0.40) and explained 40% of the phenotypic correlation between epilepsy and ADHD, with the remaining variance largely explained by nonshared environmental factors." Mmm...

Such research - although requiring quite a bit more independent investigation [2] - follows an important trend in recent times observing how stand-alone developmental and/or psychiatric diagnoses often 'clump together' in seemingly at-risk patient groups. I've for example, talked about the important concept of ESSENCE - Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations [3] on this blog and how "co-existence with other conditions was the rule" (see here) rather than the minority perspective in the area of childhood psychiatry. Now we seem to be able to add ADHD to the list of comorbidity potentially over-represented alongside a diagnosis of epilepsy (bearing in mind that epilepsy covers quite a lot of diagnostic ground).

Mechanisms? Well, far be it from me to speculate too much, but an important starting point is the nature of epilepsy and how it affects brain function. It's not inconceivable that particular alterations to the functioning of the brain as a result of epilepsy (or even during some prodromal phase) might be enough to *induce* other behaviours/symptoms to be pronounced. Equally, one might subscribe to the the idea that changes to brain function due to other events or factors that may be connected to conditions such as autism or ADHD or DCD could be enough to induce the onset of epilepsy (this hypothesis draws support from the onset patterns typically seen in cases of autism and epilepsy). I don't doubt that relationships are likely to be complicated.

Much more needs to be done on this topic, not least in ensuring appropriate screening services when cases of epilepsy are diagnosed, particularly in childhood. With no medical or clinical advice given or intended (don't mess with epilepsy), I do wonder whether some of the peer-reviewed data talking about dietary changes being used to manage certain types of epilepsy also potentially impacting on presented symptoms of *some* other labels (see here) might also provide some clues as to potential shared mechanisms between epilepsy and other developmental/psychiatric labels?

----------

[1] Brikell I. et al. Familial Liability to Epilepsy and Attention-Deficit/Hyperactivity Disorder: A Nationwide Cohort Study. Biol Psychiatry. 2017 Aug 12. pii: S0006-3223(17)31858-9.

[2] Caplan R. ADHD in Pediatric Epilepsy: Fact or Fiction? Epilepsy Curr. 2017 Mar-Apr;17(2):93-95.

[3] Gillberg C. The ESSENCE in child psychiatry: Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations. Res Dev Disabil. 2010 Nov-Dec;31(6):1543-51.

----------

Thursday, 19 October 2017

Weighing up genetics and environment in autism - reanalysed

Consider this post a sort of add-on to a previous entry (see here) published on this blog talking about the relative contributions of genetics and environment when it comes to autism. On that previous blogging occasion, the findings reported by Sven Sandin and colleagues [1] were the source material and the observation: "Heritability of ASD [autism spectrum disorder] and autistic disorder were estimated to be approximately 50%." The press release accompanying those results was titled: "Environment as important as genes in autism, study finds."

Now the same data has been though a bit of a re-analysis [2] and a slightly different conclusion and media headline - "Autism is mostly genetic, suggests study" - has been created. The reason for the quite different conclusions reached: "Instead of looking at just one time point when both members of a sibling pair had been diagnosed, they incorporated the fact that not all siblings would be diagnosed at the same time. They may start as being undiagnosed, then one would get diagnosed and, later, another might be determined to have autism" according to another media take on the findings (see here). I can't argue with the logic.

The data - 37 570 twin pairs, 2 642 064 full sibling pairs, 432 281 maternal and 445 531 paternal half sibling pairs - were now analysed in the context that diagnoses of autism/ASD among siblings are, for many reasons, not always uniform in timing. The influence of genetics or more specifically, heritability was subsequently boosted up to 83% (previously suggested to be 50%) and with it, 'nonshared environmental influence' relegated to an estimates 17%.

I've perhaps been a little unfair by using the word 'relegated' in the context of non shared environmental influence in relation to autism. There are plenty of examples out there whereby such influences might impact on autism risk: prenatal valproate exposure, congenital rubella syndrome, various types of encephalitis being linked to autistic symptoms onset (see here and see here for examples), etc and these are not to be downplayed. Environmental factors can be pretty important.

But it's critical to also mention that genetics do seem to play quite a significant role in many instances of autism too. Yes, the idea of an 'autism gene' is already a distant memory replaced by something altogether a lot more complicated, but when taking into account notions such as the broader autism phenotype (BAP) for example, one cannot discount that particularly in multiplex families, heritability is probably [mostly] driven by genetics and science still needs to continue looking at the specific hows-and-whys (see here for one example). I might add that looking at gene expression over just structural genetics is probably going to be useful in these days of epigenetics and the like.

And whilst the research of Sven Sandin is being discussed today, another recent paper where the name has appeared [3] has suggested that "little or no maternal genetics contribution" is the order of things when it comes to heritability and autism...

----------

[1] Sandin S. et al. The Familial Risk of Autism. JAMA 2014; 311: 1770-1777.

[2] Sandin S. et al. The Heritability of Autism Spectrum Disorder. JAMA. 2017; 318(12): 1182-1184.

[3] Yip BHK. et al. Heritable variation, with little or no maternal genetics contribution, accounts for recurrence risk to autism spectrum disorder in Sweden. Biological Psychiatry. 2017. Sept 21.

----------

Wednesday, 18 October 2017

Tobacco smoking and psychiatric illness

"The prevalence of smoking has remained alarmingly high among individuals with schizophrenia and bipolar disorder, and the disparity with those without psychiatric disorders and with the general population is increasing."

So said the findings reported by Faith Dickerson and colleagues [1] who surveyed nearly 2000 people "about their cigarette smoking at enrollment into a research study for which they were selected without regard to their smoking status." Their findings make for important reading in the context that tobacco smoking is not exactly a healthy activity (see here) and could potentially contribute to some of the health inequalities already recognised when it comes to serious mental illness (SMI) (see here).

The sorts of figures of smoking prevalence observed by Dickerson et al are not to be ignored: "62% of individuals with schizophrenia, 37% with bipolar disorder, and 17% of participants without a psychiatric disorder (control group) reported that they were current smokers." This set in the context of falls in the rates of smoking in the general population. It's also worthwhile noting that being a 'current smoker' with reference to a diagnosis of schizophrenia or bipolar disorder typically meant smoking "more cigarettes per day" than the control cohort.

There are other implications from this work. Without generalising (or stigmatising) if one draws on other work talking about a possible connection between prenatal nicotine exposure and offspring [heightened] risk of schizophrenia for example (see here), a complex pattern of *association* seems to emerge. No, I'm not saying that every woman with schizophrenia who is pregnant will smoke through their pregnancy (despite evidence of some increased risk [2]) but greater focus and education on the need to restrict tobacco smoking during that critical period is perhaps warranted. Such discussions may also have implications for the whole nature-nurture debate with regards to such psychiatric diagnoses too.

Although there are many (many!) good reasons for encouraging those with a SMI to quit smoking, I do feel it is important also to understand why so many are smokers. The findings reported by Li and colleagues [3] offer something of a perspective on this issue where for example: "Smokers had a higher mental QOL [quality of life] than non-smokers... in MDD [major depressive disorder]." Similarly, Mallet and colleagues [4] discussed results that suggested that "some therapeutics may improve daily smoking behavior in smokers" in the context of schizophrenia (as others seemed to be associated with 'not improving' smoking behaviours). In short, the roads that lead to, and perpetuate tobacco smoking in the context of SMI are likely as complex as the ones needed to lead people away from such habits...

And aside from the health reasons to quit smoking particularly among those diagnosed with a SMI, the grand review, meta-analysis and meta-regression paper by Cassidy and colleagues [5] lists tobacco smoking as one potentially important (and modifiable) correlate when it comes to risk factors for suicidality in schizophrenia...

----------

[1] Dickerson F. et al. Cigarette Smoking by Patients With Serious Mental Illness, 1999-2016: An Increasing Disparity. Psychiatr Serv. 2017 Sep 15:appips201700118.

[2] Nilsson E. et al. Women with schizophrenia: pregnancy outcome and infant death among their offspring. Schizophr Res. 2002 Dec 1;58(2-3):221-9.

[3] Li XH. et al. Prevalence of smoking in patients with bipolar disorder, major depressive disorder and schizophrenia and their relationships with quality of life. Sci Rep. 2017 Aug 16;7(1):8430.

[4] Mallet J. et al. Cigarette smoking and schizophrenia: a specific clinical and therapeutic profile? Results from the FACE-Schizophrenia cohort. Prog Neuropsychopharmacol Biol Psychiatry. 2017 Oct 3;79(Pt B):332-339.

[5] Cassidy RM. et al. Risk Factors for Suicidality in Patients With Schizophrenia: A Systematic Review, Meta-analysis, and Meta-regression of 96 Studies. Schizophr Bull. 2017 Sep 23.

----------

Tuesday, 17 October 2017

"What are the sex-specific recurrence rates of autism spectrum disorder among siblings?"

The paper by Nathan Palmer and colleagues [1] attempted to shed some light on the question posed in the title of this post: "What are the sex-specific recurrence rates of autism spectrum disorder among siblings?" The topic of sibling recurrence rates with regards to autism has been discussed for quite a few years (see here for example).

Already covered by Spectrum (see here), the Palmer data was derived from the records of a US health insurance organisation covering the period between 2008 and 2016 and some 3 million+ children. Researchers specifically looked at those in receipt of an autism diagnosis and onward to "estimate high-confidence sex-specific recurrence rates of ASD [autism spectrum disorder] among siblings." In other words, how many boy and girl younger siblings of children with autism were also diagnosed with autism or an ASD and whether the gender/sex of the older diagnosed sibling was an important variable in recurrence risk.

The answers: well, first it's worth noting that that prevalence of ASD came out at ~2%. This was based on administrative health insurance records remember, so is probably quite accurate given that such schemes have to 'pay out' for certain services/provisions as and when autism is diagnosed. Such a figure also adds to other data highlighting this upward trend in cases diagnosed (see here and see here).

Then: "When a male was associated with risk in the family, ASD was diagnosed in 4.2%... of female siblings and 12.9%... of male siblings. When a female was associated with risk in the family, ASD was diagnosed in 7.6%... of female siblings and 16.7%... of male siblings."

You can perhaps see that there were some subtle differences in the autism/ASD recurrence rate according to the sex/gender of the child first diagnosed with autism in a family. The Spectrum review of this paper quotes the lead author saying: "For a girl to emerge with [autism] in the first place indicates that that is a high-risk family" indicating that the appearance of females with autism might mean a greater genetic load is already present in relation to autism risk for example, which then affects subsequent recurrence risk for autism in later born siblings. That is, if one assumes that genes are the be-all-and-end-all of autism risk (see here)...

What else would I like to see in future investigations? Noting the name Isaac Kohane as part of the authorship group of this paper and acknowledging his past contributions to the autism research landscape with a focus on comorbidity and autism (see here) I do wonder if more could be done on that topic with autism recurrence in mind. Y'know, accepting that various psychiatric and somatic comorbidity are 'over-represented' following a diagnosis of autism (see here), a little more information on what else might be recurring alongside autism could provide some important clues about hows-and-whys, particularly bearing in mind that 'autism genes' aren't necessarily just genes for autism (see here)...

----------

[1] Palmer N. et al. Association of Sex With Recurrence of Autism Spectrum Disorder Among Siblings. JAMA Pediatrics. 2017. Sept 25.

----------

Monday, 16 October 2017

Vitamin A supplementation and autistic symptoms: hidden away but no significant effect...

I used the words 'hidden away' in the title of this post because I had a bit of a time deciphering the findings reported by Juan Liu and colleagues [1] (open-access) investigating "the role of VA [vitamin A] in the changes of gut microbiota and changes of autism functions in children with ASD [autism spectrum disorder]." Vitamin A by the way, is a fat soluble vitamin involved in various process such as immune function and vision health. There is a darker side to vitamin A however, as safe upper limits have been in place for quite a few years, particularly for pregnant women as a result of potential teratogenic effects.

Suffice to say that after 6 months of VA supplementation - "participants with an insufficient plasma retinol status (<1.05 μmol/L) received VAI [vitamin A intervention?] with a dose of 200,000 IU once orally" - the authors reported seeing no significant changes in autistic signs and symptoms as measured before and after using the Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS) and Social Responsiveness Scale (SRS). They did however report changes in retinol status (a marker for vitamin A availability) coinciding with supplementation: "The plasma retinol level increased from 0.59 ± 0.19 μmol/L to 0.72 ± 0.20 μmol/L in the group of 64 after 6 months of VA supplementation" and changes in the percentages of vitamin A levels (typical, marginal deficiency, deficient) across their group. I say this however, based on their use of high performance liquid chromatography (HPLC) with photodiode-array detection for assaying for retinol; state-of-the-art about 30 years ago and now superseded by better detection technology such as mass spectrometry...

No mind, Liu et al also looked at "CD38 and acid-related orphan receptor alpha (RORA) mRNA levels" as "autism-related biochemical indicators’ changes" following supplementation. RORA - retinoic acid-related orphan receptor-alpha - has some research history discussed before on this blog (see here). Authors reported that: "After 6 months of intervention, plasma retinol, CD38 and RORA mRNA levels significantly increased" despite the seeming lack of effect on presented autistic symptoms.

Further: "Fresh stool samples were collected from participants who did not receive supplemental probiotics or prebiotics and who were not treated with antibiotics for the previous 1 month." Said poo(p) samples - pre and post-vitamin A supplementation - were analysed alongside food diaries and food frequency behaviours. Authors observed that bacterial species showed changes between the baseline and post-intervention samples; specifically settling on "significant increases in the proportion of Bacteroidetes/Bacteroidales and decreases in Bifidobacterium after the VAI, accompanying significant increases in autism biomarkers, while no significant changes were observed in autism symptoms."

What can we make of these collected findings? Well, whilst vitamin A deficiency is something to look out for among children with autism [2] (see here too) and previous research has indicated "an empirical basis for the development of a pharmacological ASD treatment strategy based on retinoids" [3] the lack of a significant behavioural effect from vitamin A supplementation in this case cannot be just glossed over. Yes, this was an open-trial - "we aimed to conduct a placebo-controlled intervention study, but all the participants showed an insufficient VA status and were thus enrolled into the VAI group" - and so has shortcomings but the findings of a lack of significant change across any and all of the autism-related behaviour schedules used is notable. The biological results are a little more interesting; particularly the bacterial findings. But again it wouldn't be difficult to say 'so what?' to such bacterial results given that no corresponding changes in autistic behaviour(s) were noted...

----------

[1] Liu J. et al. Effect of vitamin A supplementation on gut microbiota in children with autism spectrum disorders - a pilot study. BMC Microbiology. 2017; 17: 204.

[2] Chiu M. & Watson S. Xerophthalmia and vitamin A deficiency in an autistic child with a restricted diet. BMJ Case Rep. 2015 Oct 5;2015. pii: bcr2015209413.

[3] Riebold M. et al. All-trans retinoic acid upregulates reduced CD38 transcription in lymphoblastoid cell lines from Autism spectrum disorder. Mol Med. 2011;17(7-8):799-806.

----------

Saturday, 14 October 2017

Bullying and autism: stating the bleedin' obvious...

A short post today to reiterate the 'bleedin' obvious': children diagnosed as being on the autism spectrum are far more likely to be the victim of bullying than perpetrator (see here for a previous blog post on this topic).

This conclusion comes from the paper by Hwang and colleagues [1] based on responses to the Behavior Assessment System for Children: Second Edition (BASC-2) (parental report version). The authors initially reported that "children with ASD [autism spectrum disorder] showed significantly increased risk for bullying involvement compared to community children" potentially indicating that a diagnosis of autism does not somehow shield someone from either being bullied or indeed, participating in bullying behaviour (perpetrator). But... "after controlling for comorbid psychopathology and other demographic factors, increased risks for being perpetrators or victim-perpetrators disappeared while risk for being bullied/teased continued to be significantly elevated." Said 'comorbid psychopathology' included aggression and conduct problems as well as the signs and symptoms of depression potentially accompanying a diagnosis of autism. Indeed, aggression was pretty much linked to every type of bullying behaviour in both autism and control groups...

What's more to say on this topic? Well, further recognition that school in particular, can be a significant source of stress and anxiety for children on the autism spectrum is one thing (and potentially contributory to the stats on school refusal in the context of autism). Indeed, without trying to armchair diagnose nor artificially inflating the seriousness of bullying, I wonder whether quite a few more children on the autism spectrum need to be screened for possible post-traumatic stress disorder (PTSD) in the context of how traumatic bullying can be for a person (see here). In relation also to the point made about aggression being a common variable predicting bullying across the Hwang cohort, I wonder whether more needs to be done more generally in relation to reducing aggression in places like school and thus potentially reducing bullying behaviour more generally?

And whilst on the topic of bullying, it appears that some of the longer term effects of bullying for some might be countered by some kind of resilience (whatever 'resilience' might mean)...

----------

[1] Hwang S. et al. Autism Spectrum Disorder and School Bullying: Who is the Victim? Who is the Perpetrator? J Autism Dev Disord. 2017 Sep 21.

----------