What is HPPD?

HPPD stands for Hallucinogen Persisting Perception Disorder.

It’s an under-researched, DSM-5-listed condition¹ in which people experience distressing changes to their perception and wider experience after using psychedelics, and once the drugs have worn off. Note, perceptual changes per se are not necessarily distressing.

There are two basic types: Type-1, in which these changes occur in brief, sudden episodic experiences (like the classic ‘flashback’ phenomenon), and Type-2, in which one’s everyday perception is altered in a sustained way. Type-2 is the more commonly reported, and is usually what people refer to when they describe having HPPD.

HPPD can involve substantial distress. Its changes can prompt or contain anxiety, panic attacks, depression, suicidal thoughts, and completed suicides;² many report a strong degree of isolation and loneliness. In more severe cases especially, HPPD can impair everyday functions like work, driving, and maintaining relationships.

HPPD very frequently co-arises with dissociative disorders like Depersonalisation/Derealisation Disorder (DP/DR), in which people feel radically disconnected from their bodies and the world stops feeling real.

These effects can last anywhere from a few days to several years - some people live with them for decades.³ In up to 50% of HPPD sufferers, symptoms may spontaneously remit within five years, but this deserves further research.⁴

What does it involve?

The HPPD experience varies from subject-to-subject, but certain perceptual changes are widely-reported and shared:

• ‘Visual snow’: When the field of vision is coated with small, grainy dots like the static of an undialed TV
• ‘Haloes’ and ‘starbusts’: When objects have a bright ‘halo’ or ‘aura’ ring around them, or concentric coloured rays around light sources
• ‘Trails’: When an object moves, a trail of faint replicated images follows it
• ‘After-images’: When the outline or silhouette of an object is seen on a surface after looking away
• Acute light sensitivity: People are more sensitive to their vision ‘bleaching’ after glimpsing a light source
• Intensified ‘floaters’: Most of us have seen ‘floaters’, which are the small squiggly lines and shapes that sometimes appear in our vision. With HPPD, these floaters can become more visible, disturbing, and irritating
• Blue Field Entoptic Phenomenon: The appearance of tiny bright dots moving quickly along squiggly lines in the visual field, especially when looking into bright blue light such as the sky
• Changes to size and depth perception: Things can seem smaller (or bigger), ‘at-a-distance’, or possessing a two-dimensional quality
• Assorted psychedelic-style effects: fractal kaleidoscopic patterns, faces, ‘breathing’ walls, moving, ‘wavy’ or shaky text, flashing and strobing lights, intensified closed-eye visuals and phosphenes
• For those with Type-1 HPPD especially, a particular psychedelic experience can be entirely re-experienced - both cognitively and perceptually

HPPD subjects also report non-visual symptoms:

• Physical effects, such as head pressure, acute neck pain, unequal pupil sizes, muscle twitches
• Tinnitus and ringing of the ears
• Auditory changes

Confused and unclear thoughts

• Depersonalization/Derealization Disorder (DP/DR), in which people feel detached from their bodies and the world stops feeling real. This affects large numbers of HPPD patients (possibly as many as 90%, according to a problematic survey, in which the entire sample of 26 had prior mental health diagnoses)⁵
• Anxiety, depression and panic: According to that same survey of 26 HPPD patients, over 90% experienced anxiety and depression, and 69% suicidal thoughts. These mood changes can occur as a sudden onset (similar to the perceptual changes), and/or exist in a vicious-cyclical relationship with one’s emotional relationship with the perceptual changes

How common is HPPD?

HPPD is of unknown prevalence among psychedelic users, but tentative survey evidence suggests it’s not necessarily that rare. A 2011 survey of 2,455 users of psychedelics via Erowid,⁶ found that up to three-fifths of psychedelic users reported lingering changes, 25% in ways that were seemingly-permanent, and 4.2% in ways so distressing that they could prompt seeking clinical help. The latter is suggestive of diagnostic HPPD.

What drugs cause it?

LSD, magic mushrooms, ayahuasca, 2-CB, ibogaine, etc., but also related (but not classically psychedelic) drugs like MDMA, cannabis, dextromethorphan (DXM), datura, ketamine,⁷ salvia, and diphenhydramine (DPH)⁸ have been implicated in HPPD.

LSD may be the leading cause. This may be a function of the LSD experience itself - especially its extended duration compared to psilocybin, for instance - or that LSD may be the most commonly-used psychedelic in adult use settings. A study of perceptual changes among experimental subjects found more presence of these phenomena for psilocybin than LSD.⁹

Can non-psychedelic drugs create these perceptual changes?

Yes. SSRI antidepressants,¹⁰ antibiotics,¹¹ antipsychotics,¹² and nootropics¹³ have been described in self-reports as triggering very similar visual changes. There is also considerable overlap between HPPD/post-psychedelic perceptual changes and another drug-free condition known as Visual Snow Syndrome (VSS).

At the same time, compared to other drug classes, it seems that psychedelics (in particular LSD) provide a higher risk factor for developing these perceptual changes. We also do not know whether psychedelic-induced perceptual changes (as described under HPPD) are interchangeable with those caused by other drugs. It may be that psychedelic after-effects are of a different kind.

How can you avoid HPPD?

1. This has not yet been fully evidenced, but there is reason to suspect that the immediate period after a trip - say, one-to-five days - is important.

This is because the brain is still neuroplastic and affected by psychedelics for up to a week (or longer) after the trip.¹⁴ And HPPD may be understood as a problem of ‘re-setting’ one’s brain back into its ordinary perceptual categories after the shock of a psychedelic experience.

If you want to avoid HPPD, what could matter, then, is ensuring that your perception re-transitions to its prior sober state safely. In this one-to-five day period, it may be advised to…

• Sleep well
• Avoid cannabis and further drug taking - some people report that their HPPD was ‘kicked in’ by a subsequent drug experience
• Process the psychedelic experience through dedicated integration practices, such as journalling, contemplation, meditation, and inquiry
• Keep stress and anxiety to a minimum
• Re-embodiment - or, re-connecting to body sensations - practices may be recommended, including through mindfulness meditation. This may help to reduce the risk of dissociative disorders like Depersonalization-Derealization, too
• Reduce screen use - focusing on screens may cause a dis-embodying effect, as well as ‘damming’ the psychological energies activated by the psychedelic experience
• Avoid triggering environments, such as places that are enclosed or rich in blank surfaces, and try not to self-induce visuals through staring and fixation
• If someone wants to be extra-careful, they may wish to avoid the places where they had their psychedelic experience
• All this is because ‘training’ the brain in ‘hallucinatory’ ways of seeing while it’s neuroplastic may cause lingering changes once neuroplasticity is reduced and stable categories re-affirmed

2. Optimise your set and setting

• HPPD seems to be more likely after bad trips and challenging experiences,¹⁵ whose likelihood strongly depends on how people organize their set and setting
• In particular, stress and trauma going into a psychedelic experience may be a trigger for HPPD experiences, even at low-dose (and microdose) levels

3. Have you experienced some unusual visuals before?

• HPPD patients may have had a higher-than-normal experience of certain visual oddities, which are rare parts of normal perception
• In particular, phenomena like visual snow, haloes, after-images, floaters, and colours in the dark may suggest an underlying tendency in perception that could be triggered by a psychedelic drug to be more intense

4. Have you tested your drugs? If so, what drug are you taking?

• HPPD may be more likely with Novel Psychoactive Substances (NPSs) and Research Chemicals (RCs) with more unpredictable, less researched, and possibly-neurotoxic effects. Adulterants in street drugs may also have neurotoxic and other risky properties
• It seems that long-acting psychedelics like LSD are more likely to cause HPPD. While LSD may have certain advantages over other psychedelics subjective to each user, someone very conscious of developing HPPD (at least compared to other risks) may be wish to avoid LSD in favour of a shorter-acting psychedelic

5. How often are you tripping?

• Taking lots of psychedelics frequently is likely to be correlated with a higher risk of developing HPPD.

• This can be explained in a number of ways:

- A higher likelihood of having a bad trip

- Activating a latent genetic susceptibility

- More likely to over-excite relevant perceptual circuits

- More ‘re-training’ of perception in ‘hallucinatory’ ways of seeing

- Less time in which to integrate properly one’s experiences, and a possibility of a ‘cascade’ of neuroplasticity from taking psychedelics while still in a neuroplastic state

6. Do you have experience of Obsessive Compulsive Disorder (OCD), Autism Spectrum Disorder (ASD), Complex PTSD, Generalized Anxiety Disorder (GAD), or Attention Deficit (Hyperactivity) Disorder (ADD/ADHD)?

• While there has not been research on the relationship of HPPD to these conditions, reviews of online forums directly and indirectly suggest a relationship
• People with Visual Snow Syndrome (a closely-related disorder covered below) seem to experience these conditions more than average based on rough overviews, and people with these conditions may independently report certain visual changes similar to HPPD

What should I do if I want to help my HPPD?

• Meditation and relaxation exercises: The core priority is reducing the distress. This is what defines HPPD, and makes it different from merely experiencing perceptual changes in general, which don’t have to be stressful.
• Meditation, yoga, breathing exercises and other techniques are known to lessen stress and anxiety. Meditation can also help to break the cycles of fixation that feed anxiety and the intensity of visuals.

If you developed HPPD after a bad trip, however, or have otherwise experienced trauma, meditation can be dangerous. Trauma-sensitive mindfulness practices may be recommended in this case.¹⁶

• See a clinician and ask for advice on medication: If you are experiencing great distress, it may be advised to begin a course of psychiatric medication, in particular Lamotrigine (an anti-epilepsy drug) and Klonopin (a benzodiazepine). Many HPPD patients report success in reducing the intensity of their visuals and the associated anxiety, but this isn’t the same for everyone.
• Side effects and withdrawal symptoms may be experienced, too, and there have been no controlled trials on the efficacy of these drugs (only case reports and anecdotes).
• Exercise: As well as its more general benefits, exercise may specifically counteract (through ‘synaptic pruning’) visual change at the level of the brain.
• Healthy diet: As well as the ‘low hanging fruit’ of cutting out fast food, reducing sugar intake, and drinking plenty of water, you may benefit from paying particular attention to how your visuals relate to specific foods. Some report success from elimination diets in overcoming a related condition known as Visual Snow Syndrome.
• Stabilise and recover sleep: Fatigue is strongly-associated with more intense visuals.
• Supplements: Some HPPD patients report success with supplements like: Magnesium, Lion’s Mane mushroom extract, N-Acetylcysteine (NAC), Vitamin D & Fish oil

But these supplements have also been reported to make some HPPD patients’ symptoms worse, and it’s encouraged that people do not go down a ‘rabbit hole’ of fixating on supplements

• Abstinence: If you want to be risk-averse - and you’re committed to eliminating your visual changes - it will not hurt to stop consuming some or all psychoactives.
• Continuing to take psychedelics and cannabis, at least in the short-term after the onset of HPPD, can be risky - though some do report overcoming their perceptual changes with psychedelics (perhaps wait for dedicated research if you want to explore this possibility).
• Some report success from ceasing caffeine and alcohol, too. Alcohol can lessen visuals in the short-term, but they can bounce back even harder with hangovers.
• Re-framing: It may be helpful to learn that many people are not troubled by their perceptual changes. Again, they can be just a ‘thing’ - how one sees now - that’s different, and not necessarily bad.
• Other people actively enjoy their perceptual changes or view them in a spiritual way - such as glimpsing auras, having broadened the possibility of the mind, or in seeing the intrinsic shakiness of ordinary experience.
• Without a deep, embodied grounding for your re-framing, though, it can be hazardous. Make sure the frame is not just ‘in your head’, but truly held across your entire mind and body in a felt way. Don’t gaslight yourself into ‘enjoying’ your perceptual changes if they are actually disturbing you.
• Avoid enclosed and dark environments: Visuals are made more intense when your vision is constrained, as with a small room versus a wide-open horizon. If you can, raising the light in an environment can be useful, because the dark provides greater contrast for visuals to appear.
• Sunglasses: Some people report real success in wearing shades - especially special tinted blue or orange glasses.

References

¹ American Psychiatric Association. (2013). Substance-Related and Addictive Disorders. In Diagnostic and statistical manual of mental disorders (5th ed.) https://doi.org/10.1176/appi.books.9780890425596.dsm16

² Lewis, D. M. (2020). Faces of HPPD: Hallucinogen Persisting Perception Disorder Patient Survey Results and a Descriptive Analysis of Patient Demographics, Medical Background, Drug Use History, Symptoms, and Treatments. Addictive Disorders & Their Treatment, 19(1), 36-51.

³ Noushad, F., Al Hillawi, Q., Siram, V., & Arif, M. (2015). 25 years of Hallucinogen Persisting Perception Disorder-A diagnostic challenge. British Journal of Medical Practitioners, 8(1), 37-40.

⁴ Abraham, H. D. (2001). New hope for hallucinogen-induced persistent perceptual disorder? Journal of Clinical Psychopharmacology, 21(3), 344.

⁵ Lewis, D. M. (2020). Faces of HPPD: Hallucinogen Persisting Perception Disorder Patient Survey Results and a Descriptive Analysis of Patient Demographics, Medical Background, Drug Use History, Symptoms, and Treatments. Addictive Disorders & Their Treatment, 19(1), 36-51.

⁶ Baggott, M. J., Coyle, J. R., Erowid, E., Erowid, F., & Robertson, L. C. (2011). Abnormal visual experiences in individuals with histories of hallucinogen use: A web-based questionnaire. Drug and alcohol dependence, 114(1), 61-67.

⁷ Abraham, H. D., & Salzman, C. (2017). Hallucinogen Persisting Perception Disorder Following Therapeutic Ketamine: A Case Report. J Alcohol Drug Depend, 5(281), 2.

⁸ Lerner, A. G., Gelkopf, M., Skladman, I., & Oyffe, I. (2002). Flashback and hallucinogen persisting perception disorder: clinical aspects and pharmacological treatment approach. Israel Journal of Psychiatry, 39(2), 92.

¹⁰ Mayby (2012). Can one get HPPD from taking an SSRI?. HPPD Online. Accessed: 12 Feb 2022.

¹¹ Morbide (2012). HPPD and antibiotics. HPPD Online. Accessed: 12 Feb 2022.

¹² Abraham, H. D. (1983). Visual phenomenology of the LSD flashback. Archives of General Psychiatry, 40(8), 884-889.

¹³ The Schizotypal (2020). 2-Dimensional Vision After Noopept. Querky Science. Accessed: 12 Feb 2022.