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Ever heard of acid flashbacks? Had visuals while sober that remind you of tripping? There’s a term for this: Hallucinogen Perception Persisting Disorder (HPPD). 

What is HPPD?

HPPD is a condition where people experience hallucinations or distortions to the way they see things. These are often similar to effects from drugs they’ve taken in the past. HPPD could happen to anyone who uses drugs that cause hallucinations, such as LSD.

Common visual symptoms of HPPD may include: [1]

     Geometric hallucinations - Seeing geometric patterns or shapes on the surface of objects or across your vision.

     Movement in your visual field - Still objects may seem to sway or move in different directions.

     Flashes of colour in visionYou might suddenly see vivid and unexplained bursts of color.

     Intensified coloursThings may appear more colourful.

     Trails or tracersYou might see lingering traces of a moving object that trail across your vision.

     Halos around objects - Objects may appear to be glowing at the edges.

     Size distortions - Some objects appear larger or smaller than they really are. These visual distortions are experienced while sober and are ongoing. HPPD can last anywhere from a month to decades, although for most people symptoms fade within a year.[2]

You may also emotionally or mentally feel like you are tripping again. This is sometimes called a ‘flashback’ since people may feel as though they are reliving moments from a previous trip.

What can trigger HPPD?

HPPD is primarily linked to the use of LSD (acid). Other known triggers include alcohol, cannabis, ketamine, MDMA, psilocybin, 2C-B, mescaline, ayahuasca, salvia divinorum, DXM and synthetic cannabinoids.[3] [4]

 While HPPD is uncommon, there is always some chance of getting HPPD from taking drugs that can cause hallucinations. That being said, most people who use drugs don’t experience symptoms of HPPD.

If you’re already getting HPPD symptoms, taking drugs can intensify and worsen your symptoms.

“When I had HPPD, smoking weed would make me feel like I was tripping super hard again. It worsened my symptoms both while I was high and for about a week after. I decided to stop tripping or smoking weed and my symptoms faded over a few months."

- Dave (name changed)

As Dave found out, taking other drugs, including alcohol, may cause your HPPD symptoms to get worse. You might need to slow down or stop taking drugs for a while until your HPPD symptoms have decreased, especially if you find they’re getting in the way of your daily life or are distressing for you.

There’s some evidence that SSRIs (selective serotonin reuptake inhibitors – a common type of antidepressant) can worsen your HPPD symptoms.[5]

Everyone has different experiences with HPPD

Some people only experience mild HPPD, where hallucinations are rare and barely affect general functioning. For people who fall into this category, HPPD isn’t usually problematic.

“I often forget I have HPPD. I’m lucky that mine is super mild. When I was younger and doing acid, I would get the occasional shifting cloud or if I unfocused my eyes I would see a spiral of black lines, like some kind of portal. Now that I don’t do acid that often, it’s pretty rare that I get it, and when I do, it doesn’t last very long.”

- Kate (name changed) 


“I took a huge dose of LSD in 2019 and it permanently changed the way that I see light refracting through water. I always see little rainbows if any light is refracting through water. This is unproblematic and honestly very cool. I also had a couple of intense flashbacks where I felt like I was back in the trip, one of these was while I was at work at a construction site which was dangerous but I just sat down until it passed. If I was driving or something it could have been very bad. These never lasted longer than 5-10 minutes.”
 - Dylan (name changed)

For others, HPPD can significantly impact their daily sober life, with intense or distressing symptoms that can last as long as years or even decades.

“I pretty much always see geometric patterns all over my vision. At first, the visuals were so intense that it was hard to focus on anything for long. A few times it caused me trouble while driving or at work. Things have improved over the last few years as I’ve focused on my health, but symptoms haven’t gone away completely.”
 - Aaron (name changed)

What to do if you have HPPD symptoms that concern you

Avoid taking drugs as these could make your symptoms worse. Some people find that HPPD symptoms are reversible with time and taking a break from drugs that trigger symptoms for them.

Take care of yourself in the usual ways: try to eat, sleep, stay hydrated and get some exercise. Reach out to those close to you – talking things over can help a lot. Check out some of our top mindfulness tips for getting through tough times. 

If you are experiencing intense or upsetting hallucinations that are impacting your ability to function in your daily life, it’s important to get support. Consider reaching out to a mental health professional or a doctor. This is especially important if symptoms of HPPD are accompanied with experiences of dissociation, derealisation and/or depersonalisation.

If you need someone to talk to, or to be connected to other mental health services, call Lifeline – 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP).

If you’re thinking of harming yourself or another person, this is a medical emergency – seek help straight away. If you or someone else is in danger, call 111. Otherwise call the Suicide Crisis Helpline on 0508 TAUTOKO (0508 828 865).


[1] https://www.theravive.com/therapedia/hallucinogen-persisting-perception-disorder-dsm--5-292.89-(f16.983)

[2] https://www.frontiersin.org/articles/10.3389/fnins.2021.675768/full

[3] Abraham, H. D. (1983). Visual phenomenology of the LSD flashback. Arch. Gen. Psychiatry 40, 884–889. doi: 10.1001/archpsyc.1983.01790070074009

[4] https://www.neurogroup.org/hppd/causes/

[5] https://www.sciencedirect.com/topics/neuroscience/hallucinogen-persisting-perception-disorder

Title image by Yumi Kim on Unsplash

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