Thursday, 11 February 2016

2% of UK 16-year olds with chronic fatigue [syndrome]?

"CFS [chronic fatigue syndrome] affected 1.9% of 16-year-olds in a UK birth cohort and was positively associated with higher family adversity. Gender was a risk factor at age 16 years but not at age 13 years or in 16-year-olds without high levels of depressive symptoms."

So said the findings reported by Simon Collin and colleagues [1] which also gained some media interest as per an entry on the BBC news website for example (see here). Based on data generated by the Children of the 90s research initiative (ALSPAC to you and me), researchers looked to estimate the prevalence of the condition in some 5,700 youth participants.

I say looked to 'estimate the prevalence' of CFS but I don't think they formally screened/assessed for the condition on this occasion; rather sending out questionnaires to parents and youth regarding "unexplained disabling fatigue lasting ≥6 months." As per the introduction of SEID (see here) to CFS (and ME) such questioning addresses one aspect of CFS but not necessarily all. One also has to be slightly careful about spreading the label too liberally [2] so as not to dilute what CFS means to many, many people and potentially including many presentations under the current banner [3]. I'll say something further about this shortly.

Authors reported an overall prevalence of chronic fatigue of ~2% in their cohort. This figure fell somewhat when "excluding children with high levels of depressive symptoms" to something like 0.6%. Further, when also looking at data "obtained from the National Pupil Database" and cross-linking it to findings, they found that authorised school absences were higher for those with CFS. This follows previous work from this research group already covered on this blog (see here). Finally, the authors talk about how being female and "family adversity" seemed to be more frequently associated with chronic fatigue. As far as I can ascertain however, no other measure (biological or genetic) was included in the study as it stands.

Set within the context of 2015 seeing a real ramping up of research into CFS/ME (see here) and some rather public discussions on what may (or may not) be the best way to manage/treat the condition (see here), the Collin findings are an interesting addition to the research base. As per the accompanying press release, the idea that family adversity - that "included poor housing, financial difficulties and a lack of practical and/or emotional support for the mother" - seemed to play something of a role in the findings goes some way to "dispelling the commonly held view that CFS is a 'middle-class' illness or 'yuppie-flu'." The same authors have also talked about other factors linked to adolescent fatigue in other publications [4] but I'm minded to be a little careful around suggested ideas like "children whose mothers experience anxiety and/or depression between pregnancy and child's age 6 years have an increased risk of developing chronic disabling fatigue in early adolescence." I think many people have had quite enough of hearing about 'psychosomatic explanations' of CFS/ME (see here) and would perhaps prefer further concentration on more pertinent biological and/or genetic processes. I'd also like to see the term 'yuppie flu' stricken from any text where CFS/ME is also mentioned.

Significantly more resources need to be put into looking at CFS/ME (including identification [5]) and what can be done to alleviate the condition particularly when one sees how much it can affect a person (see here and see here) and those around them. As per my previous ramblings on the topic (see here and see here) I'm pretty firmly sold on the idea that whilst psychology will (inevitably) be affected by a diagnosis, targeting the underlying genetics [6] and biology of the condition is the way forward (see here for example) mindful that there probably is no universal one-size-fits-all intervention for this 'spectral' condition.

Just before I go, I do want to return to that point about what exactly comes under the banner of CFS/ME based on the Collin study findings and some other goings on. As per the example detailed by Jason et al [3], one has to be a little cautious about what one includes under labels such as SEID. To quote: "many individuals from major depressive disorder illness groups as well as other medical illnesses were categorized as having SEID" based on the lack of exclusionary criteria applied to this new label. I kinda get the impression that set within the viewpoint of CFS/ME being a 'psychological condition' still unfortunately prevalent in some quarters, conflating certain depressive illnesses with CFS/ME could be used to serve an important purpose when it comes to things like presenting certain intervention options above others. At the very least, it provides a handy distraction from looking at more objective biological information potentially pertinent to at least some of this patient group. We need to be very careful...

I foresee 2016 as being another important year for CFS/ME and yes, I will be blogging about the recent Roberts study on mortality statistics and CFS/ME soon enough...

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[1] Collin SM. et al. Chronic Fatigue Syndrome at Age 16 Years. Pediatrics. 2016 Jan 25. pii: peds.2015-3434.

[2] Friedberg F. et al. Prolonged fatigue in Ukraine and the United States: Prevalence and risk factors. Fatigue. 2015;3(1):33-46.

[3] Jason LA. et al. Unintended Consequences of not Specifying Exclusionary Illnesses for Systemic Exertion Intolerance Disease. Diagnostics (Basel). 2015 Jun 23;5(2):272-86.

[4] Collin SM. et al. Maternal and childhood psychological factors predict chronic disabling fatigue at age 13 years. J Adolesc Health. 2015 Feb;56(2):181-7.

[5] Collin SM. et al. Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is different in children compared to in adults: a study of UK and Dutch clinical cohorts. BMJ Open. 2015 Oct 28;5(10):e008830.

[6] Schlauch KA. et al. Genome-wide association analysis identifies genetic variations in subjects with myalgic encephalomyelitis/chronic fatigue syndrome. Translational Psychiatry. 2016; 6: e730.

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ResearchBlogging.org Collin, S., Norris, T., Nuevo, R., Tilling, K., Joinson, C., Sterne, J., & Crawley, E. (2016). Chronic Fatigue Syndrome at Age 16 Years PEDIATRICS, 137 (2), 1-10 DOI: 10.1542/peds.2015-3434