Pro-inflammatory markers and fatigue in patients with depression: A case-control study, 2020, Pedraz-Petrozzi et al

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https://www.nature.com/articles/s41598-020-66532-6

 

I had a look at this, thought it was fairly unexciting. Small sample size, straight-down-the-line division between "depressed" and "control" patients, and then throwing at lot of measures at the analysis so you can be sure something sticks. And then at the end, getting confused about whether you're actually studying depression or fatigue.

Seems to be moving us backwards not forwards. A few years ago, there were some pretty good studies showing that high levels of inflammatory markers like CRP, TNF-alpha and IL-6 were only reliably associated with certain symptoms of depression - specifically, the "somatic" ones that include things like low energy levels, fatigue, poor sleep, etc. Yep, the ones that aren't really the depression itself but we've got ourselves so messed up that we treat them as the same as what depression really is about (which is sad mood, loss of interest in life - generally, severe and otherwise inexplicable emotional distress).

This study is a good example: