HPPD on The Psychedelic Medicine Podcast

In my recent conversation with Lynn-Marie Morski, MD, JD, on The Psychedelic Medicine Podcast (opens in a new window), we talked about Hallucinogen Persisting Perception Disorder (HPPD): what it is, what people experience, and what our survey of 650 people suggests about treatment and recovery.

The podcast is produced by the Psychedelic Medicine Association (opens in a new window). Dr. Morski is a primary care physician, and her questions were the ones many clinicians and patients ask. Here is a written summary of what we covered, for anyone who prefers to read. For the full background on the condition, see my main page on HPPD.

How I came to HPPD

About seven years ago, at a Massachusetts Psychiatric Society committee dinner, Dr. Henry Abraham, who was retiring, asked me to take over his HPPD practice. Dr. Abraham was one of the first psychiatrists to describe HPPD, and he presented it to the committee that develops the diagnostic manual so that it would be recognised as a genuine disorder.

My background is in psychosomatic, or mind-body, medicine, so the condition made me curious. Dr. Abraham referred patients to me. Since then I have seen about 80 patients, and another 75 to 80 people have contacted me with questions or for help finding someone near them. HPPD remains under-recognised. At a psychopharmacology conference a few years ago, an internationally respected psychopharmacologist asked me, “What’s HPPD?” That is not willful ignorance; the condition is simply not widely taught.

What HPPD is

HPPD is a rare but serious risk of psychedelic use. It involves the spontaneous re-experiencing of perceptual symptoms first experienced during hallucinogen intoxication, causing significant distress or impairment, and lasting long after the drug use has stopped. It can follow one or more exposures to LSD or psilocybin, and also MDMA and high-THC cannabis.

There are two broad patterns:

• Type 1: intermittent flashbacks with long symptom-free intervals.
• Type 2: chronic, persistent symptoms that can be debilitating and feel like a permanent change in vision.

Symptoms people describe

The most recognisable symptom is visual snow: static or vibrating granules over the whole visual field. A visual snow simulator app can help people show a clinician what they see by adjusting grain size, speed and opacity. Other symptoms include:

• Afterimages and trails or tracers, the most frequent symptom, reported by about two-thirds of people
• Seeing movement that is not there, and drifting spots or dots in dark rooms
• Intensified colours, sharp contrasts, geometric patterns and colour flashes
• Difficulty reading, because text seems to move or change size
• Seeing light where there is none

Some associated features, none of them diagnostic, include tinnitus (about one third), floaters, a history of head trauma (8 to 10 percent) and migraine with aura (12 to 15 percent).

Visual Snow Syndrome is the same visual snow without any history of hallucinogen or cannabis use. Its cause is unknown, and it may eventually become a formal disorder. About half of the people in my HPPD population also have visual snow. See my HPPD and visual snow syndrome FAQ for more.

What our survey of 650 people showed

I built a structured questionnaire of about ten pages for my practice. Dr. Natalie Gukasyan, then medical director at the Johns Hopkins Center for Psychedelic and Consciousness Research and now at Columbia, and her colleagues expanded it and hosted it online. It was shared in Reddit and Facebook communities and drew more than 1,000 responses. The first 650 were presented at the American Psychiatric Association annual meeting.

• The sample had a median age of 28, was about 80 percent men and about 90 percent white, and was mostly college or graduate educated. It is not representative of the general public.
• About half had used mind-altering drugs 25 or more times, yet about a third developed HPPD after a single psychedelic use. About half had used only one drug, so one drug is enough.
• Onset: about one third began immediately after the trip, about 20 percent within a week, and about 20 percent between a week and a month, so roughly 75 percent began within a month. A few began months or, rarely, years later.
• LSD was the most common trigger, about twice as often as psilocybin, followed by MDMA.
• About 80 percent reported pre-existing anxiety, depression or panic. This is self-report, and people in distress may be more likely to seek out psychedelics.

Work-up and getting evaluated

In my experience, eye exams are invariably normal, and so are the MRI, CT and EEG studies that neurologists order. I still suggest an MRI, arranged through a primary care physician, neurologist or psychiatrist, to rule out rare treatable causes.

Treatment: survey self-report and my clinical impression

There are no randomised controlled trials of HPPD treatment. There are roughly 150 publications, about 10 percent of them from the last two to three years. What follows is survey self-report and my clinical impression. It is not dosing advice, and medication decisions belong with your own clinician.

• The earliest reports described benzodiazepines, which act on the brain’s inhibitory GABA system. That fits the idea of over-activity in visual pathways. In our survey, about 58 percent said benzodiazepines helped and 7 percent said they made things worse.
• Antidepressants were reported as helpful by about 11 percent and as worsening symptoms by about 33 percent.
• Of 25 to 30 commonly used psychoactive drugs, only four or five were more likely to help than harm.
• Non-medication approaches ranked high: yoga, cognitive behavioural therapy, meditation and other psychotherapy.
• Antipsychotics, often given after a misdiagnosis of psychosis, usually worsened symptoms.

Depression or anxiety that develops because of HPPD may need treatment in its own right, after a careful discussion of risks and benefits. Some people improve on an antidepressant without any change in their vision.

The impact on daily life

About 10 percent of my patients are impaired at work or school, and two or three are disabled. The most common fear is “I’ve broken my brain.” Shame and guilt are common, and an adjustment disorder with anxiety or depression is often part of the picture.

Attention amplifies symptoms, much as it does with pain: focusing on them turns up the volume, and redirection of attention, including hypnosis-type approaches, can help. Normal vision is constantly moving and the brain filters it. Anyone staring at marble tile will begin to see faces.

Course and prognosis

In our survey of 650 people, about 25 percent reported symptoms lasting up to six months, about 15 percent up to 12 months, about 30 percent one to three years, about 20 percent four to nine years, about 10 percent ten to nineteen years, and about 5 percent twenty years or more. After a single exposure the outlook seems better, often six to twelve months.

My advice: avoid all further psychedelics, including microdosing, and avoid cannabis, since high-THC cannabis often brings symptoms roaring back. Drink only moderately and never binge.

Psychedelic clinical trials

Academic research centres report very few HPPD cases. As prescription psychedelics arrive, informed consent should include the risk of HPPD, whether the treatment is aimed at PTSD, treatment-resistant depression or personal growth.

Getting help

The HPPD questionnaire (opens in a new window) is still available online. It is anonymous and collects no protected health information. Complete it, print it, and bring it to a psychiatrist or neurologist. Dr. Morski noted that a printed questionnaire would help a primary care physician refer a patient correctly. For next steps, see my HPPD help page or contact my office.

Thank you to Dr. Lynn-Marie Morski and the Psychedelic Medicine Association for the invitation. You can watch the full episode on YouTube (opens in a new window).

This article is for educational purposes only and is not medical advice.

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