I discovered this forum about 5 months ago upon acquiring HPPD, but just now decided to create an account and share my experience. It's one that I'm rarely able to relate to others'. My intent is not only to recount my own personal story, but to provide some of the valuable insight I have garnered in that time, be it information known to many here or not. This might be somewhat lengthy, but I want to write it out for those who may not fully understand what's happening in their minds as much as I can now, with what I've come to find out. To preface, and out of respect for those here who have it the worst, I'd like to state that as per the DSM-5 criteria for the disorder, I wouldn't truly say that I have an official case of HPPD, which is a term so scarcely understood by medical professionals and lends itself to be used as a misnomer. As it doesn't cause me significant distress or impairment, I am precluded from a certain diagnosis from a technical standpoint. However, I do have a form of the same condition everyone on this board shares, which I believe lacks a broader and more proper denotation. I have what you could describe as long-term effects from psychedelic use reminiscent of the trip that incited them. It is my opinion that there is little distinction between the positive effects reported by people in clinical trials involving psychedelics, and the hellish effects experienced by the unlucky few, at least in regards to the substance's mechanism of action in the brain. I believe these long term effects, benign or disruptive, are in essence the same thing, at different degrees of intensity and character, caused by the same long term neurological changes incurred by the human mind when treated with psychedelics.
Just over 5 months ago, I took my 5th and 6th LSD trips only 2 days apart. ~300 and ~375 respectively. Up until then I had had great trips, and even tried a few micro-doses, all in the span of one summer. Those last two trips were good as well, but needless to say, I overdid it. After that last trip, a day or so went by where I felt relatively normal; then after smoking weed the next night, symptoms quickly appeared. What's odd is that they were much more mental than visual. As far as visuals are concerned, I had some mild tracers, and everything was sharper and brighter, with a strobe-like appearance to fast moving objects, and smoother motion to slower moving objects, which seems analogous to the shutter speed of a camera, or at least a biological equivalent in the human mind. My conjectural view of this is that the intensity of electrical signals in the visual cortex may increase due to a lack of inhibition, whereas their frequently decreases, accounting for the aforementioned phenomena.
Mentally and even physically speaking, I felt like I was tripping on and off for over a week. I had an almost constant body high, my thoughts were somewhat erratic along with the feeling that part of my mind was still turned off or subdued, as happens during a trip. Namely, this decrease in mental acuity, which has often been described as brain fog, can be associated with a reduction of electrical activity in the DMN, or default mode network of the brain (specifically in the medial prefrontal cortex and anterior cingulate cortex), responsible for higher level intellectual processing. As this part of the brain becomes subdued, other areas begin to interact in ways they normally wouldn't, which brings about the trippy head space and the altered state of mind experienced during the acute effects of the drug. The way LSD binds with receptors in the brain is by becoming temporarily lodged in 5-HT2a (serotonin) receptors largely located on GABA releasing neurons. GABA is an inhibitory neurotransmitter. After the experience, these receptors are reabsorbed back into the cell and in average individuals take an average of a week or a bit longer to regenerate. This accounts for tolerance to the substance, but also has more drastic implications. I find it possible that in certain circumstances, such as when abusing psychedelics or possibly using them before the brain is done developing at the age of 25, these receptors may not be fully regenerated--possibly ever.
Upon researching the role of 5-HT2A receptors I found that not only the higher their prevalence, the more prone you are to the effects of LSD, but more importantly, that in and of themselves, too vast an amount can actually be a cause for anxiety, depression, mental disorders such as OCD, etc. It makes sense to me that getting rid of a number of them can be therapeutic to the right kind of person with these circumstances, but can wreak havoc on someone else, depending on their own mental predisposition and how many of those receptors you're ultimately doing away with. Additionally, and most relevant to the visual symptoms so commonly reported, is the fact that without enough GABA being released, there is less inhibition in the visual cortex as well as other areas of the brain, causing hallucinations. This is likely why benzodiazepines, which cause the release of GABA, often help people with HPPD.
A clinical trial with participants taking a single dose and reporting back a year later is much more conducive to remove only a small number of these 5-HT2A receptors long-term and improving the subject's state of mind compared to using the substance recklessly and causing too drastic of a change to be considered beneficial. As with anything psychological, an adequate balance in neural functioning and biochemistry is key, and complexity is the biggest piece of the puzzle in understanding this or any other mental alteration. There are other factors involved such as calcium and glutamate, but those I know less about. I'd appreciate anyone's contribution to scientific literature or publications about the matter.
In my case (and I don't mean to encourage anyone to follow along my footsteps), I can somehow say that my condition was more beneficial than it was detrimental. Don't get me wrong, the first week was unnerving and felt like a constant microdose, with the mental effects in the following months being still very apparent, although they have mostly declined by now. I've come to realize a lot of the thought disruptions we get with this condition are due to an increase in mental entropy, which some people may find disconcerting and others derive creativity and different perspectives from. That distinction would be largely dependent on the intensity and scope of the change, and the person's reaction to it. However what happens is old thought patterns can be weakened and the potential for brain plasticity increases, leading many to view the world differently and have inexplicably different perception for a variable amount of time after the last dose.
I took a 2 month sobriety break from everything after my onset. After that I cautiously started smoking weed again, until I realized I was fully able to and it had no ill effects on my mental or visual effects, even when I stopped again and took another break to make sure I wasn't merely deferring the symptoms--that being said, I can't say it hasn't prolonged their abatement. My visuals, however have only diminished ever so slightly. I tried salvia and it definitely exacerbated my symptoms, so I will be refraining from its use.
What I've found in this time is that my mood had increased; I gained a better appreciation for the little things in life, and for several months I kept getting this great euphoric feeling, subtler than on a trip but noticeable and undoubtedly peaceful. For some time, I would also feel the expansion of my mind come and go, sometimes becoming incredibly apparent, which was honestly one of the biggest upsides to the whole thing since it felt incredibly pleasing. I was able to feel the inside of my mind at will, and I'm curious if anyone else here has experienced that. Of course, I don't mean to belittle those of you whose long term effects have been mostly or entirely negative, and offer my condolences with the knowledge that I can't fully imagine what that kind of severity would be like. The point I'm trying to make is that when taking a psychedelic there is a definite change that happens in most people's brains, if not everyone's, which can range from subtleties in mood and perception, to full-blown deleterious effects. I've experienced my share of cognitive dysfunction and DP/DR, but it's all mostly gone by now. I felt disconnected from reality for a while, but that too went away slowly. I feel as though my case fell somewhere between a positive and a negative long-term result from using psychedelics.
My advice for anyone dealing with mild to moderate forms of HPPD is the same as anyone else on this forum will profess. Abstinence and patience. Also exercise. Hell when this first hit me I started eating healthy and exercising every other day. That along with the positive effects I was getting from from LSD use pretty much cured my depression for an entire quarter. All in all, I think the therapeutic merit that exists in psychedelics, of course not without it's very real risks, is entirely and incontrovertibly linked to responsible and moderate use, and on the individual's neurology. No, not their state of mind; granted, that can cause a bad trip, which can lead to PTSD, but I strongly believe there is a clear distinction between PTSD and what we call HPPD, even if they happen to be often co-morbid. In my case, I've always had an overactive mind, and being that the cause of most of my mental issues, LSD helped tackle the core of my problems. I have a high IQ, but I also consider myself slightly sociopathic. LSD in fact helped me regain some emotions that were all but foreign to me since childhood, such as empathy and affection. I have no doubt that if I'm not extremely careful with my drug use now, these positive effects may turn into unwanted ones, and just to reiterate, I'm advising the utmost caution to anyone who has had any indication of HPPD. Lastly, what I'm saying is that the change LSD has on the brain is obviously not just psychological but neurological, and more complicated than the few dedicated scientists studying it can fully comprehend, let alone all of us here on this forum. For that reason I think it would be a good idea to contribute what knowledge we have, which is obviously more anecdotal than rigorously scientific, and compile it somehow to create potentially useful data. Perhaps by creating surveys to find out exactly what circumstances led to which degrees of HPPD in this community, cross referenced with age and drug use history, frequency and amount of use, and duration of symptoms.
TL;DR: At least read the last 2 sentences.