For Those With HPPD, The Acid Trip Never Ends

Published April 16, 2015
Updated November 9, 2023

For anyone experimenting with mind-altering drugs, the prospect of having a “bad trip” is a rather unsettling one. But what if the trip never ends?

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Source: Giphy

For anyone experimenting with mind-altering drugs, the prospect of having a “bad trip” is a rather unsettling one. But what if the trip never ends? What happens when drugs are taken and the drugs have metabolized fully from your system, but the effects don’t dissipate? What would it be like to never stop tripping?

For sufferers of Hallucinogen persisting perception disorder (HPPD), that’s a question they don’t have to ask themselves, because they live it every day.

The mechanism behind HPPD isn’t entirely clear, but what science does know is that it’s not the same thing as “acid flashbacks” — once someone has taken LSD (or other mind-bending hallucinogens, like peyote) they can occasionally have psychological flashbacks (similar to post-traumatic stress disorder) to some of the more unsettling aspects of their experience “tripping”. HPPD, on the other hand, consists of visual disturbances which don’t come and go. They’re constant and, unlike flashbacks, aren’t psychological. The sufferer knows that what they’re seeing isn’t real, and the disturbances are more like a short-circuit in perception rather than a bad memory.

These visual changes may have started during a trip, but once the drug has left the body, they persist and become part of the person’s waking life. Symptoms like “trailing” of objects, changes in color perception and motion-based experiences like “the walls are moving” are all common complaints of those with HPPD. Another common occurrence is the presence of “after images”, which happens when you look at an object, look away and still see it in your field of vision, usually in the negative colors scheme.

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It’s actually not uncommon for all of us, drugs or not, to experience these kinds of visual disturbances when we’re overtired, ill, in poorly-lit spaces or other situations that stimulate our visual cortex. The difference is, for most of us these experiences are temporary and exceptionally fleeting; for those with HPPD it becomes how they perceive the world all the time, regardless of the environment.

But why? That’s the question researchers have. It’s clear that there is a link between taking a psychedelic drug and developing HPPD, but it’s not as though everyone who has ever dropped acid develops HPPD. Some who have done drugs consistently for decades don’t develop any of these visual disturbances on a chronic basis and others, who have done the drugs but once, almost immediately develop symptoms consistent with HPPD.

What research has shown is that for those who do develop it, it tends to occur early on in their experimentation with psychedelic drugs.

Since it doesn’t seem to be proportional to the amount of drugs taken, or the amount of time the drugs have been consistently used, it implies that some people may be predisposed to developing HPPD if and when they should experiment with mind-altering substances. What complicates this theory is that there does exist a group of HPPD sufferers who are long-term drug users who have experimented with multiple psychedelic drugs, which makes it nearly impossible to conclude which of them ultimately led to the development of HPPD.

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One common denominator among sufferers appears to be the experience of “a bad trip” prior to the onset of HPPD. Whether it was their first trip or not, experiencing a “bad trip” was a shared experience among HPPD sufferers studied by Dr. Henry David Abraham, one of the few academics to actually study the condition.

He established that while not all drug users who had bad trips developed HPPD, those who did have HPPD had experienced bad trips. But the study was small-scale, and to date no large scale, longitudinal studies have been done on HPPD.

Whether or not there is a genetic predisposition to developing HPPD, there are demonstrable brain changes: when given visual acuity tests while undergoing a brain scan, the patient’s poor performances were correlated with unusually high brain activity in various sight-related centers of the brain. On a neurological level, it’s almost as though the brain is overstimulated by external stimuli (like colors, movement, etc.) and has a hyperactive response, causing these visual disturbances in people with HPPD.

Usually our brain is able to filter out visual “noise” and let us focus only on what we need to see; it’s why we don’t perceive “trails” or “after images”. But in hallucinogen persisting perception disorder, it’s almost as though the filter is turned off, and sufferers are experiencing visual stimuli too vividly.

This also leads to trouble perceiving objects moving in space, which gives the illusion of trails, halos and other disturbances that can make everyday activities not just frustrating, but dangerous. Driving and even walking on the street may not be possible for someone with severe HPPD.

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Drug use, especially psychedelic drugs, is rife with cautionary tales and no doubt the “trip that never ends” is one of the most convincing. But for those who are already suffering, finger-wagging will do little to allay their symptoms. The reality is, studying these patients is likely to provide insight into other conditions that are characterized by over-stimulation, visual disruption and hallucinations.

In broad terms, studying how the brain can change from a single occurrence, whether it’s drugs or trauma, can lead us to a greater understanding of depression, anxiety, schizophrenia and psychosis. While HPPD has been part of the DMS-V since the mid-1980s, very little progress has been made in understanding and treating the condition. At this point, treatment is essentially palliative: some patients have found antiepileptic drugs help to “take the edge off” and others find that wearing sunglasses all the time helps them to navigate the world in a more visually normative way.

The prevalence of HPPD in the general population is unknown, but websites like Erowid provide the casual observer with a glimpse into the life of someone with HPPD, constantly seeking out answers in a world where they must constantly straddle the line between life and dreams.

Savannah Cox
Savannah Cox holds a Master's in International Affairs from The New School as well as a PhD from the University of California, Berkeley, and now serves as an Assistant Professor at the University of Sheffield. Her work as a writer has also appeared on DNAinfo.
John Kuroski
John Kuroski is the editorial director of All That's Interesting. He graduated from New York University with a degree in history, earning a place in the Phi Alpha Theta honor society for history students. An editor at All That's Interesting since 2015, his areas of interest include modern history and true crime.
Cite This Article
Cox, Savannah. "For Those With HPPD, The Acid Trip Never Ends.", April 16, 2015, Accessed April 20, 2024.