Alright it's been a couple weeks. Be aware this is comorbid ADHD and HPPD so YMMV.
So far, success actually! keppra on its on own made me really tired, lethargic, and lots of brain fog(though thankfully, keppra rage doesn't seem to affect me noticeably). I rarely had bouts of DP before which I was happy about, but the first week of keppra had many periods of detachment. As I stated before, I was planning on being on keppra a few weeks first and then try my ADHD meds but these side effects made me want to quit in less than a week. So I started taking my adhd adderall meds to experiment with. Now since for most of this time I've been on both, Its hard for me to narrow down which one helped with what etc, but they do seem to be helping.
Do I still have symptoms? Yes, keppra by itself did not seem to help visual symptoms much. However, together, keppra and adderall seem to work synergistically for MY symptoms. My adhd meds seem to remove keppras noticeable side effects like lethargy and brain fog. Keppra seemed to remove this build up of exponentially increasing visuals I would get after taking my adderall for several days. Without keppra, after a few days of adderall I would have constant large black splotch artifacting, the walls would be melting, etc. Very, very distressing and anxiety producing. My visual symptoms still increase from baseline when I take my meds, just not to nearly the same level, nor do they seem to "build" over several days of taking it(I can see how much it helps when I miss my 2nd keppra dose by several hours, symptoms increase pretty immensely). Having this consistent "new baseline", makes getting used to the symptoms MUCH easier, and my quality of life has improved immensely. My ADHD has also been helped somewhat, I am more productive with what I put my mind to, though putting my mind to doing something productive is still difficult, so I'm still struggling with school a bit.
So, would I suggest others give Keppra a shot? Yes, definitely. Though how much it affects your particular visuals can vary quite a bit it seems, and it does come with some annoying side effects(though for many they go away or are heavily reduced with time). For people with comorbid HPPD and ADHD, absolutely try keppra. I had been doing pretty badly in school(part of the reason I experimented with hallucinogens) and finding out I had adhd only AFTER getting hppd seemed like a one-two punch. Me not being able to take the meds really made me feel kinda hopeless. Keppra + adderall xr have given me a lot more hope for the future. Now I just need to work on better scheduling, and dedicating myself to my work