In the next of our guest blog posts, paediatric mental health expert @MaxDavie has leapt into a discussion of one of the Archive’s recent editors choice articles, “Depression in paediatric chronic fatigue syndrome“.

While I don’t have a huge feel for the CFS/ME market, being largely responsible for anthracyline induced cardiotoxicity and ifosphamide tubulopathies, I do have a range of patients with co-existent “physical” and “mental” disorders, and it’s certainly worth a read. Feel free to add your comments below or argue away on Twitter.

Max also blogs here, so pop and visit too.

This useful cross-sectional study tells us that there is a significant increase in rates depression in CFS, compared to the general population, to 29%. The magnitude of this increase is stated by the authors as ten-fold, but for several reasons it is hard to be precise about this:

Firstly, they did not have a control population assessed in the same way as their CFS population, and so comparison is made with other study results.

Secondly, their population was assessed for depression by questionnaire, rather than clinical assessments, and this may have had the effect of exaggerating the disparity when compared to other studies, as there is obvious symptom overlap between CFS and depression.

Finally, this study was done on a population attending a specialist centre, who would tend to be at the more severe end of the CFS spectrum, and so perhaps more likely to be depressed.

All of these factors may lead to an exaggerated increase in prevalence. Nonetheless, there is clearly a very large amount of depression in the CFS population, and this is not in itself a great surprise. However, this study does offer tantalising clues to the following interesting question of causation:

Is the depression as a result of the CFS, is the CFS as a result of premorbid depression, or are both due to a common neurocognitive vulnerability? There will obviously be a bit of all three, but…

• Depression was associated with severity but not length of disease, which suggests the depression is not solely caused by the chronically wearing experience of CFS.

• Notwithstanding the above, the degree of increase in depression is greater than studies examining pre-morbid mental health problems in CFS have found (e.g. Rangel at al 2003), so pre-morbid depression is unlikely to explain all of this increase.

• The finding of correlation with severity but not duration of CFS is consistent with the idea of a neurocognitive vulnerability underpinning the severity of both depression and CFS. This is an idea with interesting research implications, and is another blow against the unhelpful mind/body dichotomy that often rears its head around CFS.

So, what are the implications for the DGH paediatrician struggling with a CFS caseload?:

1. Do not embark on treating CFS without decent support from mental health services

2. Screen for depression when making an assessment for CFS

3. Treat the young person as a whole, not as physically and, separately, mentally unwell.