There seems to be this weird disconnect between people saying “but what about bad trips?” and psychedelic researchers basically shrugging their shoulders and replying “we actually don’t see these in clinical trials”. Is one explanation that clinical trials screen out certain people, eg those susceptible to schizophrenia, who are most liable to react badly to psychedelics?
In terms of bad trips, this is not an accurate reflection of the science. Many studies have reported bad trips (challenging experiences). We have done so many times at Hopkins. We have even developed a validated scale to assess them. They happen on about 1⁄3 of sessions at a high dose, which doesn’t mean it lasts the whole session but that can happen too (although far more infrequently). However I call them challenging in this context because most folks report valuing these experiences and learning from them in the long run, and because with the safety guidelines in place, the really bad outcomes like harming themselves or others are substantially mitigated. We have done extensive survey work on bad trips in non-clinical use as well. For example: https://pubmed.ncbi.nlm.nih.gov/27578767/ , https://pubmed.ncbi.nlm.nih.gov/28781400/ , https://pubmed.ncbi.nlm.nih.gov/27856683/ . HPPD is a different topic. This is complex but the take homes are these. We have never seen this in the thousands of participants in either the modern era or older era (50s-early 70s) of clinical psychedelic research. So this very rare disorder likely has something to do with rare predisposition and polysubstance use frequent among illicit use. My best guess is that HPPD is not unique to psychedelics at all, but that is a rare neurological condition that is also precipitated by other drugs (like alcohol, benzos, tobacco, etc.) or even no drug at all, but that psychedelics have gotten the historical attribution due to their sensational nature. See: https://pubmed.ncbi.nlm.nih.gov/27822679/ . I’ll also note that in illicit use (although not in clinical research) it is not infrequent for folks to report visual effects one or a few days after a psychedelic, but these go away and are typically not distressing, and these are not the same as HPPD, which is a chronic and very distressing disorder. Other things sometimes referred to as “flashbacks” is likely an instance of state dependent learning, where meditation, cannabis, a warm relaxing bath, etc., and start to elicit a strong reminder of the earlier psychedelics effects. Again, this is not the same as HPPD.
What’s the current state of research into ‘bad trips’ and hallucinogen-persisting perception disorder?
There seems to be this weird disconnect between people saying “but what about bad trips?” and psychedelic researchers basically shrugging their shoulders and replying “we actually don’t see these in clinical trials”. Is one explanation that clinical trials screen out certain people, eg those susceptible to schizophrenia, who are most liable to react badly to psychedelics?
In terms of bad trips, this is not an accurate reflection of the science. Many studies have reported bad trips (challenging experiences). We have done so many times at Hopkins. We have even developed a validated scale to assess them. They happen on about 1⁄3 of sessions at a high dose, which doesn’t mean it lasts the whole session but that can happen too (although far more infrequently). However I call them challenging in this context because most folks report valuing these experiences and learning from them in the long run, and because with the safety guidelines in place, the really bad outcomes like harming themselves or others are substantially mitigated. We have done extensive survey work on bad trips in non-clinical use as well. For example: https://pubmed.ncbi.nlm.nih.gov/27578767/ , https://pubmed.ncbi.nlm.nih.gov/28781400/ , https://pubmed.ncbi.nlm.nih.gov/27856683/ . HPPD is a different topic. This is complex but the take homes are these. We have never seen this in the thousands of participants in either the modern era or older era (50s-early 70s) of clinical psychedelic research. So this very rare disorder likely has something to do with rare predisposition and polysubstance use frequent among illicit use. My best guess is that HPPD is not unique to psychedelics at all, but that is a rare neurological condition that is also precipitated by other drugs (like alcohol, benzos, tobacco, etc.) or even no drug at all, but that psychedelics have gotten the historical attribution due to their sensational nature. See: https://pubmed.ncbi.nlm.nih.gov/27822679/ . I’ll also note that in illicit use (although not in clinical research) it is not infrequent for folks to report visual effects one or a few days after a psychedelic, but these go away and are typically not distressing, and these are not the same as HPPD, which is a chronic and very distressing disorder. Other things sometimes referred to as “flashbacks” is likely an instance of state dependent learning, where meditation, cannabis, a warm relaxing bath, etc., and start to elicit a strong reminder of the earlier psychedelics effects. Again, this is not the same as HPPD.