Jump to content


  1. Research - Actively Recruiting

    1. Research Advertisements

      The approved advertisement will be listed here for all approved research.

  2. Main Forums




      This is the catch-all forum for posts. Discuss anything related to Hallucinogen Persisting Perception Disorder (HPPD) here.

    3. Introductions

      A place to introduce yourself to the community and what you hope to seek out on this site. New members may share their experience and onset of HPPD and what drug(s) triggered it.

    4. Symptoms: Descriptions, Discussion, Debate

      What are the symptoms? What do you feel encompasses HPPD?

    5. Medications & Other Treatments

      The place to discuss pharmacological and other treatment options.

  3. Active and Future Research

    1. Research Articles, Publications and Studies

      Articles, publications and studies for review and discussion.

  4. Community Area

    1. Community Open Space

      This is a location to talk about anything except your symptoms. Be respectful of other users, but any topic within the rules are open for discussion.

    2. Forum Information, Questions and Suggestions

      Is the forum missing something? Do you have any ideas or suggestions? Any problems or questions? Post them here.

  • Who's Online   0 Members, 0 Anonymous, 11 Guests (See full list)

    • There are no registered users currently online
  • Member Statistics

    Total Members
    Most Online
    Newest Member
  • Forum Statistics

    Total Topics
    Total Posts
  • Hallucinogen Persisting Perception Disorder (HPPD) support forum - HPPD, flashbacks, drug-induced visual snow syndrome and depersonalization/derealization.

    Common HPPD symptoms: visual snow, palinopsia (trails/afterimages), increased BFEP, increased floaters, ghosting, halos, starbursts, macropsia/micropsia, geometric hallucinations, closed-eye visuals, flashbacks, depersonalization/derealization, anxiety, depression, brain fog, cognitive dysfunction, tinnitus.

  • Recently Active Topics

  • Latest Posts

    • Je pensais que tu faisais une FMRI  
    • Ok, so it would appear that its quite likely that the glutamate release is activated by 5ht2a/5ht receptors, and would pretty much solidify the neurotoxicity or any 5ht2a agonist, specific to interneurons. Here is the study that basically shows the link between glutamate and 5ht2a. https://www.nature.com/articles/1395430 So, I think everything really came around and connected everything together finally. 5ht2a agonism increases glutamate, we know already glutamate storms are neurotoxic. The neurotoxicity is mediated through reactive oxygen species leading to mitochondrial DNA damage/failure, which is going to cause them to signal apoptosis, leading to intraneuronal loss. Interneurons are regulatory neurons and without their involvement excitatory neurons will act unregulated giving the symptoms of HPPD. The only thing that can show otherwise at this point is if say classical hallucinogens like LSD or DMT etc do not show the same release of glutamate. But based on the study posted here I think its likely it will be the same.  What some people may be wondering then is why do some not appear to get HPPD and others do, but in this case the answer is simple. Because eventual neuronal loss is caused by reactive oxygen species its going to be mediated through various antioxidant profiles and according to one of the studies it looks to be glutathione, people who do not appear to get HPPD realistically are still probably losing neurons, however in the case of people with HPPD they likely have altered glutathione levels, which can occur for various reasons. Well I'll try and add some positivity for anyone reading this, cause even after studying this for 10 years now this is a pretty hard read. The positive side is, that interneurons as far as I understand are specifically close proximity neurons and have short connections, so recovery under stimulation of neurogenesis is likely to be higher than say if long distance axons were damaged/lost. To say that other neurons in the surrounding areas are not affected, I'm not sure, but when I have time I will look in to the possibility. I think though this most likely explains the cause and etiology of HPPD. Maybe we can get the information stickied so that people understand what it is that these compounds do, and will help to prevent the future use of them. It explains as well why benzodiazepines assist the best in the condition but do not mute the symptoms entirely, is that there are no receptors/synapses/neurons to exhibit GABA for excitatory neurons, and it is probably acting on downstream neurons that still have their interneuron connections. Big thanks to @MentholFlavoring for find those studies.
  • Recent Status Updates

    • thequestioner827  »  David S. Kozin

      Hi David, I was wondering if you had a full text version of the paper you posted here:
      I have university access to PubMed and Medline but I'm still unable to find a full-text version, only an abstract like what is posted here.
      Thanks in advance!
      · 0 replies
    • since92  »  David S. Kozin

      Hi Dave, I see in your profile pic one of your original posts from 1999, then I see that you joined this one in 2010.  Is it possible to see posts from the forum that we all used to message on - I'm presuming that you and I were on the same one forum?   It's because another user and I are looking for people we messaged with back in 2003 but I think though that I had a different user name in those days.  Do you know of that forum and whether we can access posts from those days?  I would like to see those early posts of mine because they had a lot of info about how my HPPD developed etc..  Many thanks.
      · 0 replies
    • David S. Kozin

      Haven't slept longer than 4 hours in three days.
      My HPPD is off the charts.   will not be available at all today. Please contact Jay1 for all of your needs. 
      · 0 replies
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.