HPPD stands for Hallucinogen Persisting Perception Disorder, to non-psychedelic users, you may have only heard this term, but not much more than that. HPPD is a neurological disorder which can occur after the use of psychedelics. It is purely visual and is not accompanied by any mental effects. Changes in the brain which cause HPPD are disputed, and there is currently no definitive answer to what changes in the brain lead to its occurrence. According to a 2011 Study, approximately 23.9% of regular psychedelic users experienced constant HPPD-like effects, though only 4.2% considered seeking treatment due to its severity¹. Furthermore, there are theorized to be two types of HPPD², type 1 and 2. Users with type 1 HPPD may experience brief "flashbacks", which is where a user will experience brief psychedelic effects for a few seconds, this usually goes away relatively soon after using psychedelics. Type 2 is described as far more severe, this is where a user experiences long term changes in their vision after using psychedelics. It is normal for type 2 HPPD to last a couple of years, although lasting a lifetime is rare. The symptoms of HPPD are as follows:³

• Afterimages: After looking at an object for a while and then looking away, a positive or negative image of the object remains visible.
• Color Confusion: It is difficult to tell colors apart. Colors may appear to change over time. Example: a red sweater may turn yellow, or black text in a book may turn bright green.
• Reduced Color Discrimination: Some subjects report a reduction in the brightness or fidelity of colors, sometimes making it harder to tell similar colors apart.
• Difficulty Reading: Text may sway back and forth. Letters leave positive and negative after-images. Letters may vanish into an "alphabet soup".
• Flashes of color: Subjects may see bright lights, flashes, or sheets of color that appear and disappear.
• Geometric Patterns: Subjects see geometric patterns and shapes. Example: leaves in a tree may form patterns.
• Halos around objects: Objects appear to have halos that extend for some distance around their edges.
• Images within Images: Subjects see faces or other complex images where none exist. Example: a hardwood floor may appear to be made out of faces.
• Movement: Stationary objects appear to sway back and forth or slide across the floor. This is most common in the peripheral vision.
• Size Distortions: Objects temporarily seem to be smaller or larger than they actually are and then return to their normal sizes.
• Static: Subjects see static over monochrome surfaces. This is especially noticeable at night. Example: in a totally dark room it may look like there is a TV set turned on broadcasting static.

So how can I Avoid Getting it? Well, I hate to say it, but the only way to 100% ensure you will never get HPPD is to never touch drugs, but let's be honest, the world doesn't work that way. There are a few things you can do. One of which is being aware of which drugs cause HPPD most commonly. According to a paper published by Dr. Abraham⁴ (the leading researcher on HPPD), HPPD is most commonly caused by LSD use, although it is important to remember that LSD is the most commonly used psychedelic. According to this paper, other drugs, such as cannabis, can also cause HPPD.

Another important thing to note is that according to many user reports, HPPD most commonly arises after negative experiences.³ While some people have developed HPPD after nothing but positive experiences, this is less common. This further highlights just how important it is to only use psychedelics in a setting where you feel safe and comfortable. If you do not feel like that at the time, just wait, do it another time. I promise you, it isn't worth it. In addition, it is also important to note that certain people seem to be more prone to HPPD use than others, suggesting a genetic link. It is theorized that if you are prone to HPPD, you are likely to develop the disorder after a few experiences.

According to surveys conducted by Erowid, many people get HPPD after their first experiences with HPPD, for these people, unfortunately, there are no warning signs. I myself have had Type 2 HPPD for nearly 2 years after a low dose of LSD. However, many people develop HPPD slowly after long-term heavy hallucinogen use. For these people, there are often warning signs. These symptoms can include things such as brief flashbacks, mild tracers in very dark lighting, and slightly reduced color confusion.³ If you are a heavy psychedelic user and you start to experience symptoms like these, my advice to you is TAKE A BREAK. Taking a good break from psychedelic use is worse than long-term HPPD, trust me. Furthermore, many people often obsess over symptoms of HPPD which are present in a large amount of the population anyway, this can lead to people convincing themselves they have it. An example of this is the 'static' symptom. For example, seeing static in a pitch-black room is completely normal, however many people convince themselves this is a result of HPPD.

I've Developed HPPD, what now? First of all, please, try not to stress out about it to the best of your ability. When I first got HPPD, constantly obsessing over it and looking for all the symptoms made it much worse. There are many resources out there which explain HPPD well as well as people sharing their experiences. I cannot stress this enough, DO NOT GO READING THESE, they will lead to you becoming even more stressed about it. The absolute best advice I can give to anyone who has developed HPPD is to try and not think about it as much as possible, get on with your life, go outside, go to work or school or whatever it is you usually do, just please try to not obsess over it. In addition to this, you really need to try and completely cut most drugs out of your life. My personal recommendation is to cut all drugs completely, although I understand this is incredibly hard for some, but at least please, do not use psychedelics or cannabis, as these have been proven to worsen symptoms, the same goes for stimulants. 2 years in, I now barely notice HPPD, I often can go a month without giving it a single thought. The reason for this is because I don't let it consume my life. I want to reiterate again, this is the best advice I can give. If you obsess over the symptoms, you Will notice them more, if you ignore them, you will hardly notice them, or won't notice them at all.

It is important to remember that your brain does not heal in days and weeks, but in months and years. It will take time for the symptoms to go, just get on with your life as if it isn't there.

Alternatively, there are some medications which have shown to have some positive effects in treating the symptoms, however I am not a doctor so I will not give advice on them, however all the information is available on the Wikipedia page for HPPD: Wikipedia - HPPD

To conclude, HPPD is a complex and under-researched disorder, it is non-psychotic, meaning it is purely visual⁵. It can be relatively hard to predict on who will get it and when, although I hope the advice I have given will be useful. If you have any further questions or need any more advice on HPPD, please do not hesitate to reply to this or send me a direct message. Also, below are some pictures which aim to represent what some of the HPPD symptoms look like, although it is important to remember these are just pictures, and not the real thing:

Visual snow visualization: Visual Snow

Tracers: Tracers

Thank you for reading.

Sources used:

1. 10.1016/j.drugalcdep.2010.09.006 Baggott MJ, Coyle JR, Erowid E, Erowid F, Robertson LC (March 2011). "Abnormal visual experiences in individuals with histories of hallucinogen use: a Web-based questionnaire". Drug and Alcohol Dependence. 114 (1): 61–67.
2. doi:10.1007/7854_2016_457 Halpern JH, Lerner AG, Passie T (2016). "A Review of Hallucinogen Persisting Perception Disorder (HPPD) and an Exploratory Study of Subjects Claiming Symptoms of HPPD". Behavioral Neurobiology of Psychedelic Drugs. Current Topics in Behavioral Neurosciences. Vol. 36. pp. 333–360.
3. Erowid - HPPD FAQ
4. Abraham HD. Visual phenomenology of the LSD flashback. Arch Gen Psychiatry; 40: 884-889, 1983
5. doi:10.3389/fnins.2021.675768 Vis PJ, Goudriaan AE, Ter Meulen BC, Blom JD (2021). "On Perception and Consciousness in HPPD: A Systematic Review". Frontiers in Neuroscience. 15: 675768.