Found this while looking to see if I could find any link between POIS and TBI. I had an injury to the head very young (freak accident thing). From what I understand from parents, doc just thought I was ok, not concussed, but also not that much understanding of such things back then probably. I was later diagnosed with thyroid problems as a young adult, which I suspect looking back may have been present much earlier and simply not spotted until later. And I remembering experiencing POIS-like symptoms since I reached puberty and started exploring that side of myself; I had no reference to it or comparison, but I remember being more low energy, depressed, anxious, in my teens, which coincides with the introduction of those symptoms and doubtless feeling less capable and alert as a person.
Having historically shown up as a more quiet person in my family, it was likely easy to mask and for no one to spot as something off, other than me.
I've also been wondering about any crossover links to SCT (see Russel Barkley's talk from 2018 about how it is a distinct condition from ADHD and may have some relationship to TBI). What if SCT is related to POIS and both stem from some kind of disruption in brain processing as a result of injury? I wonder if anyone has studied for links between the two (probably not yet).
I was also listening to an interview the podcast Neurohacker did with Dr. Barry Komisaruk who has studied the effects of orgasm on the brain. Nothing directly related to POIS in there, but I wanted to mention it because I noted that he mentioned all parts of the brain get activated during orgasm. I'm wondering about the intersection of TBI and orgasm, if an injury can cause the chemicals that relate to sleepiness after orgasm to get released in some kind of hugely disproportionate amount, causing this kind of state of overwhelm, where it takes much longer to normalize. And/or if the injury can disrupt the processing of related chemicals, such that it becomes difficult for your brain to sort of "level out" afterward, instead lingering overly long in this altered state. Or the joint activation of different parts of the brain perhaps itself creates some kind of overwhelm that would normally be easy to recover from. I'm not a neuroscientist, but just trying to grasp at any connections because there's so little to go on.