Krystle Cole: What are the symptoms of Hallucinogen Persisting Perception Disorder (HPPD)?
Dr. John Halpern: The symptoms of HPPD varies by person but essentially what happens with this disorder is a person will re-experience some or all of the sensory/perception changes that were uniquely induced while under the influence of an hallucinogen. The scientific literature yields several cases of non-hallucinogens doing the same – with reports on marijuana and alcohol causing such disturbances. People with HPPD sometimes report their symptoms worsening when using alcohol or marijuana, as well. But the symptoms of HPPD most commonly are visual – reports of “trails” (eye tracking slows such that an afterimage is perceived such as when you wave your hand before your face) or micropsia/macropsia (seeing things smaller than they are or larger) and/or perceiving images or special thoughts that had occurred while on a hallucinogen. People with HPPD often report photosensitivity -light as a trigger for re-activation of these symptoms. Anxiety is a large component of HPPD – people typically erroneously come to believe that they must have “damaged their brain” and the anxiety and other symptoms of HPPD are not unlike then posttraumatic stress disorder where the traumatic event is the hallucinogen experience – and typically it is reported as a “bad trip.”
What about “flashbacks?”
In fact, “flashbacks” has at times been used interchangeably with “HPPD” but “flashback” only describes the remembrance of the experience; HPPD refers to not just a “flashback” but to the constellation of unsettling symptoms associated with it. Having a pleasurable/enjoyable “flashback” is called by some users “a free trip” and that would not be HPPD because it is not unsettling and/or not having a clinically significant impact on the person’s life. My literature review paper on what we know about HPPD offers much more detail on symptoms, diagnosis, and treatment and has been uploaded for NeuroSoup members.
A few additional points: most people with HPPD recover within a month or two after last use; a few take as long as a year; some claim permanent visual changes since use of a hallucinogen. Interestingly, many people with HPPD continue to use hallucinogens.
Oh, by the way, I am writing my answers using the typical term used in the scientific literature of “hallucinogen” here rather than the best descriptor (“psychedelic”) or the term that best notes these compounds religious importance (“entheogen”). I am not using “entheogen” because a number of people who use these compounds for non-entheogenic purposes are the ones who go on to HPPD. In my interview of over 1000 Navajo members of the Native American Church, not a single NAC member validated ever having symptoms of HPPD from the entheogenic (sacramental) use of mescaline-containing peyote.
KC: Can a person get HPPD from using an entheogen one time?
JH: The answer is that yes it is possible and I have definitely had a few cases of complaints after just one use. Most typically, it is LSD that can cause HPPD after one use. Indeed, almost (but not all) people with HPPD report that symptoms started after LSD. There may very well be something unique about LSD and HPPD but I also believe that there is probably something different in the visual cortex of these individuals that pre-date use of an hallucinogen. Careful neurological assessment is important because there are other disorders that may explain what is happening wrong. Quite often, though, people will describe seeing “floaters” in their field of vision as a child and/or that they had visual disturbances (such as micropsia or extreme photo-sensitivity) that also predated first use of a hallucinogen. So, while there may be something about LSD and HPPD, there may also be somethings that are unique to this population of users, as well. I suspect, however, that an extremely ill-prepared person who has issues of need for too much control in his/her personality and has an anxiety-filled traumatic bad trip that afterwards leaves the person convinced that they damaged their personality/their brain permanently – even without a history of visual disturbances pre-dating hallucinogen use – such a person may come to meet criteria for HPPD.
KC: What percentage of entheogen users actually get HPPD?
JH: A few statistics exist from over the years. I am inclined to use the most conservative statistic: about 1 in 50,000 people and most typically with LSD. HPPD is indeed rare.
KC: What are the traditional methods of treatment for HPPD?
JH: Traditionally, I’d say the best medicine is “reassurance” that the person is “not crazy” and can have a normal life… that these symptoms will resolve all on their own over the next few months for most people.
Medications that are of use:
SSRI antidepressants. We know that SSRI’s reduce post-synaptic serotonin receptor density; people on SSRI’s can have a diminished to no experience after taking a hallucinogen. It is possible that this change in receptor density somehow also reduces the post-hallucinogenic symptoms.
Benzodiazepines (valium, ativan, klonipin, xanax, et cetera). Benzodiazepines have been used most extensively for HPPD – it treats the symptoms of anxiety and that, in turn, has the HPPD symptoms “back off.” Very effective but they are used after symptoms start and should not be used prophylactically.
Naltrexone – has been reported as a useful medication for HPPD as has the alpha-adrenergic anti-hypertensive clonidine.
Some people are prescribed antipsychotics for HPPD but this is usually not necessary or a good choice. The HPPD person should have already been carefully assessed to rule out a psychiatric psychotic disorder; HPPD is NOT a form of psychosis and antipsychotics have been reported as helpful for HPPD but also as not helpful. A few case reports exist describing worsening symptoms of HPPD after initiation of risperdal and olanzapine.
KC: Are there any natural ways to treat HPPD?
JH: Absolutely! First up, as noted above: reassurance that the person is NOT crazy and has NOT caused brain damage from their use. No matter how convinced the person is of these facts… they are false.
Next, reminder of it’s time limited nature for most people (“this too shall pass”).
Biofeedback is helpful as anything that improves a person’s ability to become calm and feel then in control is helpful. So let’s add meditation, yoga, and exercise to this list…
My favorite treatment is a simple pair of sunglasses. Most people with HPPD describe symptom activation or maddeningly increased intensity of symptoms when they are in bright light… especially when changing from a dark environment to a bright one. And if one wears sunglasses, what happens? A reduction or prevention of HPPD symptoms! Does that mean wearing sunglasses into a house… or getting night-time sunglasses for driving (oncoming headlights can be quite the trigger): in short, YES. Sunglasses definitely are helpful.
Therapy: many HPPD people really did have an unsettling/disturbing experience while on the hallucinogen and have need to “talk it through.” Doing so may not just help improve self-understanding but also reduce then HPPD symptoms…. or at least the person gets some good support for a condition that most people have never heard of and haven’t the foggiest clue about what it is like to have unwanted visual disturbances sabotage their day.
KC: Are there any vitamins and/or supplements that will help alleviate the symptoms of HPPD?
JH: I am not aware of any specific natural products specific for HPPD but anything that has a sedative-hypnotic effect similar to the benzodiazepines could be used likely in place of a benzodiazepine. Valerian is one such substance.