Wednesday, 23 August 2017

Male and female autism might not be so dissimilar?

I read with some interest the paper by Joanna Mussey and colleagues [1] concluding that "either very small or no gender differences in age at diagnosis, intelligence quotient, cognitive profiles, or autism spectrum disorder symptom severity" were detected in their cohort of males (N=566) and females (N=113) diagnosed with an autism spectrum disorder (ASD).

Interest because, in these days of talk about a possible specific female autism phenotype emerging (see here) in light of potential sex differences in the presentation of autism (see here), one has to be quite careful not to over-generalise too much. In much the same way that terms such as 'male brains' and 'female brains' don't really do justice to the complexity of brain structure and function (see here), so one perhaps has to ensure that female autism and male autism presentation aren't offered in an 'either or' fashion despite the possibility of subtle differences in either the expression of symptoms or for example, differences in the presentation of things like over-represented comorbidity between the sexes/genders (see here).

Mussey et al reported that previous studies talking about autism 'hitting harder' when it comes to females in relation to the presence of intellectual (learning) disability and "more severe impairments" might not necessarily tell the full story. Based on the use of various instruments to to ascertain autistic traits and beyond, the authors noted some differences between the genders on measures of autism signs and symptoms but the precise significance was, in the most part, deemed "of minimal clinical significance." Such findings have also been noted in other recent research [2]. Another important message from the Mussey study results was that at least some of the instruments used to assess for autism or ASD might need some further investigation with sex/gender in mind.

Having said all that I do think there are still important issues that need to be further investigated when it comes to sex differences in autism presentation. The idea for example, of a 'female camouflage effect' (see here) still looms large in this area; where for example, verbal and non-verbal communication skills might serve to *mask* other important diagnostic features. I'm also [carefully] inclined to inquire whether gender identity over biological sex might play something of an important role in the male and female presentation of autism for some, in light of other important research (see here). There is a further scheme of work to be completed minus sweeping generalisations.


[1] Mussey JL. et al. Are males and females with autism spectrum disorder more similar than we thought? Autism. 2017 Aug;21(6):733-737.

[2] Fulton AA. et al. Gender comparisons in children with ASD entering early intervention. Research in Developmental Disabilities. 2017. 68: 27-34.


Tuesday, 22 August 2017

8 in 1000 babies born with foetal alcohol spectrum disorder

The results of the systematic review and meta-analysis published by Shannon Lange and colleagues [1] make for important reading with their conclusion that the global prevalence of foetal alcohol spectrum disorder (FASD) is estimated to be around 8 in 1000 live births. The accompanying editorial by Albert Chudley [2] rightly talks about 'high time for action' on the basis of such figures, particularly because FASD is a largely preventable condition and specific groups of people and specific geographical regions seem to carry elevated risk(s) when it comes to offspring FASD and so can be targeted for additional support.

Looking at the collected data from 24 studies examining the prevalence of FASD - a condition whereby babies exposed to alcohol in the womb present with specific morphological features and accompanying behavioural / cognitive issues - researchers concluded that around 7.7 per 1000 live births presented with FASD. They reported that 76 counties (of 187 countries providing data) showed an estimated prevalence rate for offspring FASD above 1% of total births. South Africa came top with over 1 in 10 births being estimated to present with FASD. Croatia, Ireland, Italy and Belarus filled the other top 5 hotspots for FASD with estimated prevalence rates between 3-5% of births derived from various methods.

'Special populations' are also mentioned in the Lange paper. Specifically: "the prevalence of FASD among special populations was 15.6 to 24.6 times higher among aboriginal populations... 5.2 to 67.7 times higher among children in care... 30.3 times higher in a correctional population... 23.7 times higher in a population with low socioeconomic status... and 18.5 times higher among a population in psychiatric care compared with the global prevalence among children and youth in the general population." One might argue that at least for some of these at-risk populations, issues such as binge drinking habits combined with an elevated risk of unplanned pregnancy [3] could lie at the root of the estimates detailed by Lange et al. I say that minus any sweeping generalisation but in light of the scientific 'facts' detailed in the latest review paper.

I note that some of the media around the Lange findings (see here) have already mentioned about some of the behavioural manifestations of FASD 'crossing over' with diagnoses such as attention-deficit hyperactivity disorder (ADHD) and autism. I would perhaps draw your attention to a previous blogging occasion when I discussed some of the research specifically looking at any overlap between autism and FASD (see here) and how one needs to be quite careful not to overplay any would-be links despite some data on possible overlap [4] (this paper was also from Lange).

Then to the specifics of the hows-and-whys of alcohol exposure in-utero causing FASD and whether effects might somehow be mitigated. Alcohol (ethanol) is a known teratogen [5] so effects are likely to be numerous in terms of how it affects the developing foetus. I note that the word 'epigenetics' has entered the vocabulary when it comes to possible mechanisms of effect(s) and that would suggest that at some point there may be ways and means of mitigating the effects of alcohol consumption at critical periods during pregnancy. At some point.

For now the message from Lange and colleagues is clear: FASD is not an uncommon finding in many different countries and different populations, and remains largely preventable. Abstinence from alcohol is advised before and during that special time (see here). And just in case anyone thinks I'm only zooming in on mums-to-be, dads might also heed similar advice at critical periods too.

Straight Edge from Minor Threat seems an appropriate song to conclude this post given what the song title means (veganism and the non-use of prescription medicines are optional extras I might add)...


[1] Lange S. et al. Global Prevalence of Fetal Alcohol Spectrum Disorder Among Children and Youth. JAMA Pediatrics. 2017. Aug 21.

[2] Chudley AE. Fetal Alcohol Spectrum Disorder—High Rates, High Needs, High Time for Action. JAMA Pediatrics. 2017. Aug 21.

[3] Font-Ribera L. et al. Socioeconomic Inequalities in Unintended Pregnancy and Abortion Decision. Journal of Urban Health. 2008;85(1):125-135.

[4] Lange S. et al. Prevalence of Externalizing Disorders and Autism Spectrum Disorder among Children with Fetal Alcohol Spectrum Disorder: Systematic Review and Meta-analysis. Biochem Cell Biol. 2017 May 18.

[5] Randall CL. Alcohol as a teratogen: a decade of research in review. Alcohol Alcohol Suppl. 1987;1:125-32.


Monday, 21 August 2017

The links between autism and ADHD: sibling study adds a new layer

'A diagnosis of autism or autism spectrum disorder (ASD) does not typically appear in a diagnostic vacuum'. I've said that sentence several times on this blog (see here for example) in line with how science has shown that many different labels (both behavioural and somatic) are over-represented when it comes to a diagnosis of autism. All very ESSENCE like (see here)...

Of the various over-represented comorbidity, attention-deficit hyperactivity disorder (ADHD) - either in symptoms or in diagnosis - is one of the more common ones (see here); something that has implications for screening (see here) and also management. The findings reported by Yi-Ling Chien and colleagues [1] (open-access) add something to the research looking at the possible hows-and-whys of ADHD appearing alongside autism with their focus on "unaffected siblings of probands with autism and Asperger syndrome (AS)." Such work ties into that observing 'unaffected by autism' does not necessarily mean 'symptom or trait-free' in the context of ideas such as the broader autism phenotype (BAP) (see here).

With the aim to "investigate the ADHD-related traits and attention performance in unaffected siblings of probands with autism and Asperger syndrome (AS), as well as the clinical correlates of ADHD-related traits" researchers concluded that generally, unaffected siblings (unaffected by autism) of those diagnosed with an ASD "were more hyperactive/impulsive and oppositional" than those so-called typically developing controls. The finding was based on the use of various questionnaires/schedules pertinent to both the "the core symptoms of DSM-IV ADHD" and also tests to "assess attention performance."

Of particular note was the observation of "more ADHD and oppositional traits in unaffected siblings of AS probands" when looking at subgroups on the autism spectrum. With caution, the authors suggest that such a finding may be evidence "that these traits might be a broader phenotype for AS." They also posit that "more severe ADHD-related symptoms in AS probands rather than autism probands suggest that these two subtypes may not be the same in their clinical expression regarding ADHD symptoms." In these days of plural autisms (see here), things seemingly get even more complicated when diagnostic subgroup x comorbidity is also thrown into the mix.

Although quite a bit more investigation is required in this area, there is at least one important point to take from the Chien work: unaffected siblings of those diagnosed with autism - particularly Asperger syndrome - may benefit from preferential clinical assessment for something like ADHD. I say that with the understanding that a diagnosis of ADHD has been linked to a heightened risk of various 'adverse' outcomes in the longer term (see here and see here) and again, minus any sweeping generalisations, specific interventions for ADHD can seemingly mitigate quite a bit of that excess risk (see here) and onward improve quality of life and more.


[1] Chien Y-L. et al. ADHD-related symptoms and attention profiles in the unaffected siblings of probands with autism spectrum disorder: focus on the subtypes of autism and Asperger’s disorder. Molecular Autism. 2017; 8: 3.


Saturday, 19 August 2017

Omega-3 fatty acids and ADHD meta-analysed (again)

"In summary, there is evidence that n-3 PUFAs [polyunsaturated fatty acids] supplementation monotherapy improves clinical symptoms and cognitive performances in children and adolescents with ADHD [attention-deficit hyperactivity disorder], and that these youth have a deficiency in n-3 PUFAs levels."

So said the results of the systematic review and meta-analysis published by JanePei-Chen Chang and colleagues [1] taking in the collected peer-reviewed research literature on the topic of fatty acids and ADHD. This continues a research theme down the years suggesting that said compounds might be beneficial for at least some people diagnosed with ADHD (see here) and screening for signs of omega-3 fatty acid deficiency could be preferentially clinically indicated for those diagnosed or at risk of a diagnosis.

I don't want to dwell too much on the results because (a) they speak for themselves and (b) this is an area of science that has been a talking point for quite a few years. I know there has been a degree of 'over-hype' associated with fatty acids down the ages but as part of a larger scheme of work suggesting that food and nutrition are not so detached from some behavioural/developmental diagnoses (see here for another example) I'm minded to suggest that they are given their due credit. Certainly fatty acid supplements are quite inexpensive and also seemingly useful for various aspects of physical health too.

As to the mode of effect, well, we don't know all there is to know just yet. I note that some of the authors on the Chang paper are not adverse to the idea that something like psychiatry and immune functions are linked (see here). Whether at least some cases of ADHD might be accompanied by more 'inflammatory' issues is still the source of some debate; although I'd be quick to add in the quite voluminous research suggesting that allergy and ADHD might have more than a passing relationship (see here). Is is possible that supplementation with specific types of fatty acids typically labelled as 'anti-inflammatory' [2] could be working as anti-inflammatory agents? Well, possibly, but I daresay there may be other biological processes at work too. More research is indicated but the Chang results provide yet more [strong] evidence that at least some of those with ADHD may benefit from a fish oil or two a day.

And whilst on the topic of fatty acids, I might also direct you to an interesting piece of research recently published by Sheppard and colleagues [3]...


[1] Chang JC. et al. Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies. Neuropsychopharmacology. 2017 Jul 25.

[2] Wall R. et al. Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Nutr Rev. 2010 May;68(5):280-9.

[3] Sheppard KW. et al. Effect of Omega-3 and -6 Supplementation on Language in Preterm Toddlers Exhibiting Autism Spectrum Disorder Symptoms. J Autism Dev Disord. 2017. July 26.


Thursday, 10 August 2017

ADHD and law enforcement contact: not a straight-forward relationship

Several times on this blog I've talked about how a diagnosis of attention-deficit hyperactivity disorder (ADHD) seems to place the recipient at quite a bit of excess risk for various unfavourable outcomes (see here). I've tried hard not to make too many sweeping generalisations on this issue; mindful that behind every statistic in every peer-reviewed bit of science there are real people and real lives. But the data is becoming quite compelling on this matter...

The paper by Mark van der Maas and colleagues [1] makes an important contribution to the idea that the relationship between a diagnosis of ADHD and contact with law enforcement 'systems' is perhaps not as straight-forward as many might believe. Concluding that: "The observed connection between ADHD and criminality may be better understood through their shared relationships with indicators of poor social bonds", researchers suggest that social factors may very well come into play.

OK, based on a sample of over 5300 adults "representative of the general population of Ontario, Canada" researchers asked participants about their "self-reported arrest on criminal charges" history alongside examining ADHD-linked symptoms via the Adult Self Report Scale (ASRS-v1.1). They also interviewed/questioned about various social bonds - household size, education level, drug and substance abuse, etc.

They observed that: "screening positive for ADHD was twice as likely... and past use of medications for ADHD three times as likely... to be associated with ever having been arrested." But... when statistical modelling took into account the data on social bonds, things started to get a little more fuzzy. So: "In the best fitting statistical model, ever having been arrested was not associated with ADHD, but it was significantly associated with indicators of strong and weak social bonds." So things like anti-social behaviour, not progressing well in educational terms and substance use (abuse) might have some important influences on contact with law enforcement agencies. A shocker, I know.

I do have to point out a few important things about this research before anyone gets too immersed in the idea that ADHD is completely off the hook. First was the reliance on self-report when it comes to both ADHD signs and symptoms and also arrest record. The ASRS might very well be a nice rough-and-ready measure of ADHD symptoms but it is no substitute for a thorough assessment for a diagnosis of ADHD. Similarly, people may not always be completely truthful when it comes to their arrest record under several circumstances including research conditions...

Second is the concept of cause-and-effect. As easy as it is to say that ADHD was not itself linked to arrest record(s), it is important not to interpret the findings to say that there is 'no connection' between ADHD and 'having been arrested'. Minus sweeping generalisations, facets of ADHD - such as impulsivity and inattention - can and do perhaps account for some of the heightened risk for various types of offending behaviour [2]. It's fine to say that these facets of ADHD might be exacerbated under conditions of substance use/abuse for example, but one could easily then ask whether ADHD might have actually been involved in facilitating such substance use/abuse in the first place. Certainly, there is (peer-reviewed) evidence that a diagnosis of ADHD - if left untreated - may very well impact on educational outcomes for example [3] which could be one of several factors in determining other life choices.

The idea however that ADHD as a sole risk factor for adverse outcomes such as law enforcement contact does not exist in some sort of social vacuum is an important one to come from data such as that presented by van der Maas et al. It is perhaps the issue of 'vulnerability' that comes to the forefront, and how an ADHD diagnosis should perhaps be explored with that tenet in mind...


[1] van der Maas M. et al. Examining the effect of social bonds on the relationship between ADHD and past arrest in a representative sample of adults. Crim Behav Ment Health. 2017 Jul 5.

[2] Berryessa CM. Attention, reward, and inhibition: symptomatic features of ADHD and issues for offenders in the criminal justice system. Atten Defic Hyperact Disord. 2017 Mar;9(1):5-10.

[3] Lu Y. et al. Association Between Medication Use and Performance on Higher Education Entrance Tests in Individuals With Attention-Deficit/Hyperactivity Disorder. JAMA Psychiatry. 2017 Jun 28.


Wednesday, 9 August 2017

Methylphenidate + fatty acids for ADHD? Erm, we need more science...

I don't mind telling you that I was left a bit baffled by the results published by Mahbobeh Firouzkouhi Moghaddam and colleagues [1] (open-access available here) talking about the use of specific polyunsaturated fatty acids (PUFAs) as a sort of add-on to more traditional pharmacotherapy indicated for cases of attention-deficit hyperactivity disorder (ADHD). Baffled because science is supposed to be presented in such a way that methods and results are easy to read and intepret and hence replicate, and appropriate conclusions are supposed to be based on those results. Read on and I hope you'll see what I mean...

Based on the use of a randomised, placebo-controlled trial design, some 40 children (6-12 years of age) who obtained "the least score in an ADHD rating scale questionnaire, responding to the treatment based on least reduction of 25% of symptoms relative to the base state in ADHD scaling" were allocated to either a methylphenidate (MPH) + PUFA ("capsules containing 180mg EPA and 120 mg DHA") group or a MPH + placebo group. Participants were monitored quite regularly over 8 weeks of intervention via the ADHD rating scale adopted and "filled by the resident of psychiatry for patients of both groups." I say all that bearing in mind that I'm not exactly sure what specific ADHD rating scale was actually used during the study.

No mind, the results: "mean severity of symptoms before treatment in both groups of methylphenidate plus PUFA and placebo was the same, and severity of symptoms after treatment in the group under methylphenidate plus PUFA treatment had reduced much more compared to the placebo group, and major changes were observed in the subscale of predominantly attention deficit type." The authors were able to describe the types of symptom patterns presenting by participants in relation to ADHD type. Indeed, quite impressively: "Response to treatment (a reduction of at least 25% in the signs) in the group taking methylphenidate plus PUFA was 90% (18 patients) and in methylphenidate plus placebo group, it was 60% (12 patients)." They did also note side-effects in both groups; the most common in both groups (taking MPH) were sleep disorders and anorexia. For the PUFA group "just one case of burping" was recorded. Researchers concluded that further trials are needed to confirm/refute their findings.

Appreciating that these study results are presented in English but English is perhaps not the mother tongue of researchers, I can get past the slightly odd tone of the article text in places. I do still have an issue with not being able to find out which ADHD scale was used during the study; something that is important if someone wanted to try and independently replicate this study.

More than that, I have to say that I am also a little hesitant when it comes to the way the statistics and findings have been presented in this paper. My first reading of the results was that MPH + PUFA supplementation was superior to MPH + placebo based on the text presented in the article. A more detailed look at the findings revealed that this was not necessarily the case based on (a) looking at the comparisons across the various types of ADHD pre- and post-intervention groups (see Table 1 of the paper) and (b) comparing 'mean severity of symptoms after treatment' between the PUFA and placebo groups (Table 2). You will see that assuming a drop in ADHD scores denotes improvement in behaviour(s), Table 1 suggests that only those with the mixed/combined type of ADHD as a group showed a reduction in scores (9.4±8.39 vs. 0.6±1.20) between pre- and post-intervention with MPH + PUFAs. This was compared with two groups in the MPH + placebo arm of the trial: predominantly attention deficit and mixed type, where a reduction was noted. In all other scenarios, the group values actually increased. Bearing in mind the authors don't actually tell us how many people were included in those ADHD groups, I was a little surprised to see that the p-values remained highly significant for all ADHD types across both study arms. One can only deduce from these findings - those presented in Table 1 - that MPH + PUFA supplementation is at best, as good as MPH + placebo for a specific type of ADHD but at worst, potentially making MPH less effective in other types of ADHD.

Then to the data showing "comparison between the mean severity of symptoms in the intervention and control groups after the treatment" (Table 2). Here again, the picture is one of no real [statistical] difference between MPH alone and MPH + PUFA supplementation after 8 weeks of intervention based on the group scores and the p-values produced. Yes, you could say that MPH + PUFA seems to show some equivalence to MPH + placebo, but then the question 'why take a PUFA supplement?' comes to the surface. And please also, none of that 'almost significant' stuff based on a p-value of 0.18 for example particularly in light of other discussions...

"This study shows that PUFA is an efficient nutrient to treat ADHD and it can be used to treat patients." I'm not so sure that this sentence is completely compatible with the study findings as they are presented; both in the text of the results and the table data. Don't get me wrong, more than most I would love to see fatty acids finding their place with at least some people presenting either with a diagnosis of ADHD or significant features of ADHD (see here and see here for examples) also on the back of some very recent peer-reviewed findings [2]. The trouble is that I don't think these are necessarily the results to show that...


[1] Moghaddam MF. et al. Effectiveness of methylphenidate and PUFA for the treatment of patients with ADHD: A double-blinded randomized clinical trial. Electron Physician. 2017 May 25;9(5):4412-4418.

[2] Chang JC. et al. Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies. Neuropsychopharmacology. 2017 Jul 25.


Tuesday, 8 August 2017

Toxoplasma infection may be a risk factor for manifestation of psychotic-like symptoms

It's been a while since I last talked about Toxoplasma gondii on this blog (see here). All the initial research excitement from a few years back on how T. gondii exposure might correlate with various psychiatric symptoms/conditions seems to have been toned down in recent times. Still, I continue to be fascinated with the idea that at least for some, exposure to T. gondii might be more than just a somatic thing...

The findings reported by Lindgren and colleagues [1] illustrate how my interest in the gondii remains justified as per their conclusion: "Toxoplasma infection may be a risk factor for manifestation of psychotic-like symptoms." Based on data from Finland - "Health 2000, a large cross-sectional health survey of the Finnish general population aged 30 and above" - the authorship team included on the Lindgren paper contain some names familiar to the T. gondii research scene: namely Faith Dickerson and Robert Yolken.

So, the presence of lifetime psychotic-like symptoms via "section G of the Composite International Diagnostic Interview, Munich version (M-CIDI)" were analysed alongside seropositivity to Toxoplasma "defined as a cutoff of 50IU/ml of IgG antibodies" in nearly 6000 participants. Various other potentially interfering variables - "age, gender, education, region of residence, cat ownership, and C-reactive protein measuring inflammation" - were also thrown into the statistical mix. Cat ownership by the way, refers to the [disputed] research hypothesis that some cats might be unwitting hosts for the gondii with potential onward implications for owners (see here).

Results: "T. gondii seropositivity was significantly associated with clinically relevant psychotic-like symptoms... and with the number of psychotic-like symptoms." That being said, presenting with an immune profile suggestive of some contact with T. gondii did not show any significant connection with diagnosed conditions with a psychotic element to them such as schizophrenia. The authors however, felt confident enough to say that psychotic symptoms might not be totally unrelated to T. gondii exposure.

Accepting that there may be various reasons why someone might present with clinically-relevant psychotic-like symptoms [2] I find good reason to continue with the research agenda looking at T. gondii exposure and human behaviour on the basis of results such as those from Lindgren. The spectrum of labels - behavioural/psychiatric - potentially *associated* with T. gondii exposure is not to be sniffed at [3]. Even if only a proportion of cases are found to be *associated* with gondii exposure, there are treatments readily available (see here) to manage the infection. Whether such intervention(s) might also provide some relief of psychiatric symptoms alongside, is something too that needs more investigation...


[1] Lindgren M. et al. The association between toxoplasma and the psychosis continuum in a general population setting. Schizophr Res. 2017 Jul 12. pii: S0920-9964(17)30391-2.

[2] Cosgrave J. et al. The interaction between subclinical psychotic experiences, insomnia and objective measures of sleep. Schizophr Res. 2017 Jul 12. pii: S0920-9964(17)30397-3.

[3] de Barros JL. et al. Is there any association between Toxoplasma gondii infection and bipolar disorder? A systematic review and meta-analysis. J Affect Disord. 2017 Feb;209:59-65.