Scientists: Protein IL-17 fights infection, acts on the brain, inducing anxiety

Surprisingly enough, this partially exposes the link between depression and some of the autoimmunal diseases. One example is how patients with psoriasis have significantly elevated levels of proteins from the IL-17 family (namely, IL-17A, IL-17C, and IL-17F) - up to 4 to 8 times above nominal values.

At the same time, bimekizumab, one of the bleeding-edge psoriasis and psoriatic arthritis treatments, suppresses production of IL-17A and IL-17F (methotrexate does that, too, albeit to a much smaller degree). As a result, people receiving IL-17 suppressors become happier over the course of years, and not only due to months-long remission - I had a chance to see this in one of the experimental treatment programs.

Interesting, I take risankizumab, which looks like it indirectly suppresses IL-17 (through suppressing IL-23A). I've been on it for a bit less than a year, and I can't say if I've had improved mood. Maybe? It definitely fixed the psoriasis. Might also have contributed to me getting sick more often, though.

I wish I had kept logs with some sort of self-screen depression instrument now (maybe the BDI? I don't like the PHQ-9). Might as well start now.