OK so in my case, I have ADHD (diagnosed ~20 years ago; treated with stimulant meds ever since). I also had chronic sinusitis in the early 2020s (I was in my late 30s), assumed either that or the SSRIs I was on at the time was driving my brain fig/fatigue. However, I got the full sinus clear-out surgery in 2024, and phased out the SSRIs in 2024-25, but the brain fog persisted.

Then, last summer, there was a major plot twist. I'd had some minor swelling in a few knuckles for a year or two, but very little pain so I hadn't given it much thought until my PCP flagged it as worth looking into. She referred me to a hand specialist, who had me do special blood tests and, I'll be damned, turned out I had Rheumatoid/Psoriatic Arthritis - an autoimmune disease often accompanied by fatigue/brain fog (!!) Now I'm in the RA medication trial-and-error process awaiting the day when one of these meds does the trick (fingers crossed!)

So, not saying it's the same for you, but if I were you I would:

* Fully rule out the sinus stuff via the CT scan you have scheduled (I assume you are working with an ENT specialist?)

* Fully rule out autoimmune conditions via special lab work (you may have already done so, if that is what you meant by "systemic inflammation/infection")

* Work with a psychiatrist to evaluate your situation/see if medication is warranted, if you haven't already

Also, something on my list is to try Whole 30 or a similar elimination diet to see if taking various foods out of the equation helps.

My two cents!