Hallucinogen Persisting Perception Disorder (HPPD)

Hallucinogen Persisting Perception Disorder

Hallucinogen persisting perception disorder (HPPD) is a chronic condition in which a person has seemingly persistent visual hallucinations following a previous hallucinogenic drug experience, without the same intoxication or altered state of consciousness that is associated with the drug. 

Several weeks, months, and even years after using hallucinogenic drugs such as MDMA (ecstasy) and psilocybin (magic mushrooms), some people experience the effects again.

A person who suffers from hallucinogen persistent perception disorder (HPPD) experiences these experiences known as flashbacks.

When taking hallucinogenic drugs, people experience an altered sense of perception that is commonly called a “trip”.

This type of experience is enjoyed by many. However, it is possible to become quite ill from using hallucinogens, depending on:

  • The kind of hallucinogen
  • The amount taken
  • Medical conditions or medication interactions

Flashbacks can be pleasant because you are able to relive the trip or the effects of the drug. They may even make you feel relaxed and at ease.

Nevertheless, some people experience flashbacks differently. Instead of an enjoyable trip, they see only perplexing visual effects. Examples include:

  • Objects with haloes
  • Distorsions in size or color
  • Consistently bright lighting

It is possible for the person experiencing these disturbances to be completely aware of all other activities going on. It can be annoying, disturbing, and debilitating when your field of vision is blocked. You may find these symptoms disturbing, upsetting or bothersome.

It is possible that you have a condition called hallucinogen persisting perception disorder (HPPD) when you experience these visual disturbances often.

Hallucinogen persisting perception disorder is not as common as flashbacks. Due to the stigma attached to recreational drug use, it is unclear how many people experience this condition.

Doctors may also be unaware of the condition despite it being officially recognized in medical curriculums.

There are two types of HPPD disorder (type 1 and type 2). The symptoms of type 1 HPPD are often short, random flashbacks. The symptoms of type 2 HPPD are often long-term, disturbing and pervasive.

HPPD disorder is a rare disease, so research is limited because so few cases are diagnosed. Researchers and doctors know little about the condition because so few cases are diagnosed.

You can learn more about HPPD, the symptoms it can cause, and how it can be treated following this article.

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How flashbacks feel

A flashback is a feeling of reliving a past experience. This can happen after using drugs. It can also happen after a traumatic event.

Flashbacks of painful and stressful situations are common for people suffering from post-traumatic stress disorder (PTSD).

There is a common thread between PTSD flashbacks and drug pleasure flashbacks. The senses tell you that you are reliving those events or trips during these flashbacks, even if you aren’t.

However, the experience of flashbacks is different from HPPD. Only visual disruption will result from the flashback. The rest of the experience will be the same.

There may be effects from the disturbance, but you might not enjoy the other effects of reliving the journey. It can become frustrating, even overwhelming when flashbacks become more frequent.

Read: Split-Brain Syndrome

Related conditions

There are some people who suffer from HPPD who experience visual disturbances along with other symptoms. The following are possible examples:

  • Panic attacks
  • Anxiety
  • Depression
  • Depersonalization disorder

Mental health conditions like depersonalization disorder can leave a person feeling like:

  • There is a disconnect between them and their bodies.
  • Life is observed rather than experienced by them.
  • Those around them seem to be in a fog or feel far away from reality.

Many patients report that they also experience these conditions alongside HPPD, despite not fully understanding how they relate to the condition.

HPPD symptoms

HPPD causes visual disturbances which are often accompanied by one or more of the following symptoms:

  • Intensified colors: The colors of objects appear more vivid and bright.
  • Flashes of color: Your field of vision may be filled with bright bursts of color that seem out of place.
  • Color confusion: Similar colors may be difficult for you to distinguish, and your mind may also switch colors. Your perception of red may be very different from everyone else’s.
  • Size confusion: Your peripheral vision may give the impression that objects are larger or smaller than they actually are.
  • Halos around objects: An object may appear to have a glowing rim when you look at it.
  • Tracers or trailers: You may see glimpses of an image or object lingering in your vision.
  • Seeing geometric patterns: Even when patterns aren’t really present, you can see shapes and patterns in something you’re looking at. An example would be that the leaves of a tree may appear to form a checkerboard pattern to you, but not to others.
  • Seeing images within images: It may appear that something is there when it isn’t. For instance, snowflakes may appear on glass.
  • Difficulty reading: Pages, signs, or screens may look as if the words are moving or shaking. Additionally, they may seem jumbled or unintelligible.
  • Feeling uneasy: You’ll be able to tell when you’re experiencing an episode of HPPD. Those feelings can lead to feelings of discomfort or embarrassment, as if something strange or bizarre is happening to you.

HPPD flashbacks have no obvious cause, so they can occur at any time. Typically, flashbacks of drug trips are not as intense or as long-lasting.

Some of the common symptoms of HPPD disorder include:

This is a symptom that is reported, but it is not included on the recognized list of symptoms in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) The cause of these symptoms has not been determined.

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Are there any common types of drug-induced hallucinations?

The victims of Hallucinogen Persisting Perception Disorder have recurrent hallucinations they experienced on psychedelic trips in the past. This is usually visual, but it can also affect other senses. A person with HPPD may notice haloes of different colors around objects or see colors more intensely.

There is also the possibility of objects appearing too large or too small (macropsia). There is even the possibility that they will see or hear someone who isn’t there. Music at a concert may sound louder than usual, and auditory experiences may be intense.

Causes of HPPD

The causes of HPPD are not fully understood by researchers and doctors. Researchers are also unsure what causes hallucinogen persisting perception disorder to begin with. There is a strong correlation between HPPD and the use of hallucinogenic drugs, but it’s unclear how the type of drug or the frequency of drug use might influence its development.

As HPPD is a rare condition, it is more often diagnosed in people with a history of mental health issues or substance abuse. However, it is possible for anyone to develop the condition, even after a single exposure to triggering drugs.

Hallucinogen persisting perception disorder can occur after a person uses a drug for the first time. Some people don’t experience symptoms until years later.

It is better to know what doesn’t cause HPPD:

  • HPPD is not caused by:
    • Brain injury
    • Epilepsy or seizures
    • Another psychiatric condition
  • These symptoms aren’t caused by an unpleasant trip. HPPD is sometimes triggered by bad trips, but not everyone who has it has been on a bad trip.
  • Your body does not store the drug and then release it later, causing these symptoms. It’s a common myth, but it’s not true at all.
  • Also, HPPD isn’t caused by intoxication right now. It is not uncommon for people to experience symptoms of HPPD weeks, months, or even years after using drugs.

Read: Sensory Processing Disorder

How HPPD is diagnosed

Seeing a doctor is crucial if you suffer from unexplained hallucinations. Any and all hallucinations should be taken seriously. This is particularly the case if you frequently have them. It is possible that your doctor will examine you, order tests, and take an MRI.

A brain electroencephalogram (EEG) may be recommended in some cases to monitor brain activity.

Inform your doctor if you have ever used hallucinogenic drugs. Your doctor will be concerned with addressing and treating your symptoms as their primary concern. You should not worry about whether you have used drugs in the past.

The doctor may recommend a psychiatric examination if the results of the testing and imaging are clear. The diagnosis of HPPD may result from a psychiatric examination if other more common diagnoses do not match.

It may be easier for your doctor to diagnose HPPD if your doctor is aware of your condition and your past drug use. A doctor will ask you about your health history and the experiences you’ve had.

Your doctor may order blood tests or imaging tests if they suspect another cause, such as side effects from medication. Testing can alleviate the possibility that there are other causes for your symptoms. When other tests are negative, you may be diagnosed with HPPD.

A doctor-patient relationship becomes more effective when both doctors can be honest about their behaviors, choices, and medical histories. You will be able to avoid potential complications from drug interactions if your doctor considers these factors.

Find a doctor who makes you comfortable if you feel like you are not being treated properly or your symptoms are not being taken seriously by your physician.

Read: Tobacco Use Disorder

HPPD treatment

HPPD is not currently treated medically. Psychiatrists who have experience treating HPPD can be hard to find since so little is known about its development. It may take some trial and error to find the right treatment for the visual disturbances and related symptoms.

Not everyone needs treatment. The symptoms may resolve in a few weeks or months.

HPPD has been linked to certain medications in a 2021 review, but limited studies support this conclusion. It is sometimes prescribed antiepileptic drugs like clonazepam (Klonopin) and lamotrigine (Lamictal) to treat seizures and epilepsy. One person’s solution may not be the one that works for another.

How to cope with HPPD

HPPD can cause unpredictable episodes of visuals, so it is good to prepare yourself with techniques for dealing with the symptoms when they do occur. If these episodes cause you significant anxiety, for instance, you may need to rest and apply anxiety breathing techniques.

HPPD episodes are actually more likely to occur if you worry about them. Stress and fatigue also contribute to HPPD episodes.

Counseling may be an effective coping method. Learning how to respond to stressors can be learned by working with a therapist or psychologist.

Read: Applied Behavior Analysis


HPPD is a rare condition. Hallucinogen users are not all likely to develop HPPD. The visual disturbances that some people experience after hallucinogenic drugs don’t happen every time. Other people may experience frequent disturbances, but don’t find them very bothersome.

Many people with hallucinogen persisting perception disorder eventually recover from their symptoms, but others experience them long-term.

The cause of HPPD and the best way to treat it remain largely unclear.  Therefore, it’s important that you work with your doctor to find a treatment technique or coping mechanism that makes you feel in control when you deal with disturbances.