Well, i read that hppd could be a genetic disorder, so that got me thinking, wouldn't a doctor that knows about the way hallucinogenics affect the genes, target that gene and attempt to fix it? Here is the quote:
"It is now thought that HPPD is possibly a genetic disorder where LSD and other hallucinogens may alter inhibitory neurons in the perceptual pathways of the brain(in susceptible individuals). These are the systems that filter the senses (well, mainly sight, possibly sound) into a full understandable picture."
Also, if some of you are wondering, i take gabapentin for my hppd, it works pretty good, but tolerance develops fast.