Many drug users experiment with psychedelic substances to expand their consciousness or to get a mind-altering high. But these recreational users may not realize that the visual and auditory hallucinations, sensory disturbances and dissociative experiences associated with psychedelic drugs can return months or even years after using a drug.

Hallucinogen persisting perception disorder, or HPPD, causes a recurrence of hallucinatory experiences after drug use has stopped.

These uncontrollable episodes can occur at any time, interfering with day-to-day activities and causing anxiety, fear and depression. The exact cause of HPPD is still unknown, and there is currently no cure for the disorder. However, leading a drug-free lifestyle can reduce the risk of developing this condition. Some former drug users have been treated successfully for HPPD with antidepressants or anti-seizure medications. Although the risk of HPPD is greater among heavy drug users, flashbacks may occur in people who have tried a drug only once or twice.

The only certain way to avoid HPPD is to avoid abusing the mind-altering drugs that can trigger these frightening hallucinations.

Diagnosing HPPD

The Diagnostic and Statistical Manual of Mental Disorders-IV-TR (American Psychiatric Association, 2000) uses the following criteria to define HPPD:
  • The individual has stopped using hallucinogens.
  • The individual is not currently under the influence of drugs or alcohol.
  • The episodes cause significant impairment in the individual’s life.
  • The symptoms can’t be attributed to another medical or psychiatric disorder.

Columbia University notes that unlike drug flashbacks, which happen only occasionally after drug use has ceased, the sensory disturbances associated with HPPD continue on a regular basis for long periods of time. An occasional, casual user of hallucinogenic drugs may have mild flashbacks for up to a year after the last drug use. HPPD is diagnosed when these flashbacks become frequent and consistent, and when they start to interfere with a person’s daily life.

Because the individual with HPPD is aware that he or she is having a hallucination, this disorder is distinct from psychiatric conditions like schizophrenia.

Individuals with schizophrenia generally believe that their delusional thoughts and hallucinatory experiences are real, while people with HPPD are conscious that their experiences do not reflect reality. However, HPPD can lead to mental illness by inspiring panic, anxiety, fear and depression in former drug abusers.

Symptoms of HPPD

California State University at Long Beach has identified three categories of drug-related flashbacks: emotional, somatic (related to bodily experiences) and perceptual (related to senses like sight and sound). People with HPPD may undergo any of these types of episodes at any time.

Emotional flashbacks may include feelings of anxiety, panic, or fear. Somatic episodes can cause sensations of dizziness, weakness, feelings of being detached from the body, shaking, or nausea. Perceptual flashbacks can make the individual see colors, objects, or patterns that aren’t there. Many people with HPPD report visual disturbances like halos surrounding real objects, trails of images, unusual colors, or snowy patterns interfering with their field of vision.

The hallucinogenic episodes of this disorder are frequently referred to as “flashbacks,” but flashbacks alone do not justify a diagnosis of HPPD.

The Israel Journal of Psychiatry and Related Sciences points out that the symptoms of HPPD differ from ordinary drug flashbacks in several important ways:
  • Flashbacks are rare and usually temporary; HPPD episodes are long-lasting and can continue for months or years.
  • Flashbacks are usually harmless and may even be pleasant; HPPD episodes are frightening and distressing.
  • Flashbacks do not generally cause negative emotional side effects; HPPD episodes can leave the individual feeling helpless and depressed.
  • Flashbacks can often be stopped with minimal treatment; HPPD is usually not reversible, or it is reversed only very slowly.

Although the symptoms of HPPD can occur without warning during any period of a person’s life, there are certain situations that can aggravate the condition. People who are under stress or who are very tired are more likely to experience flashbacks. People with a co-existing mental illness, such as schizophrenia, a mood disorder, or an anxiety disorder, are more prone to the effects of HPPD than the general population. Some people are more likely to have flashbacks in a darkened area, which may make it difficult to sleep. Others can re-experience hallucinations simply by thinking about drug experiences from the past.

Which Drugs Cause HPPD?

Any recreational drug that alters mental processes and interferes with sensory perceptions could be a potential source of HPPD. Synthetic drugs, natural hallucinogens, and even some over-the-counter medications can cause flashbacks and recurrent hallucinations.

Researchers have identified several drugs that are more likely to contribute to this disorder:
  • LSD
  • Mushrooms
  • Marijuana
  • Ecstasy
  • 2-CE
  • Diphenhydramine (an ingredient in over-the-counter allergy medications)
  • Dextromethorphan (an ingredient used in some over-the-counter cough medications)

LSD, or lysergic acid diethylamide, is the drug most often associated with HPPD, according to Drug and Alcohol Dependence. LSD is a synthetic psychedelic drug that has been used both for psychiatric research and for recreational purposes. Because the drug evokes symptoms that are similar to psychosis, LSD was explored as a tool for psychiatric investigation in the 1940s through the 1960s. In the 1960s, recreational use of LSD increased dramatically, and the drug was associated with the countercultural movement.

However, while some users claimed that their “trips” were blissful or enlightening, others reported intense feelings of terror, anxiety, sadness and loneliness after taking the drug.

LSD use was made illegal in the United States in 1967, and use of the drug declined in the 1970s and 1980s. In the 1990s, however, a new generation of young people discovered LSD, and the drug has experienced a new popularity at underground clubs, concerts, and raves. Meanwhile, synthetic hallucinogens and stimulants like Ecstasy (MDMA), methamphetamine, GHB, and ketamine are being widely abused. Even drugs that come from natural sources, like cannabis, psilocybin (found in hallucinogenic mushrooms) and peyote can alter the neurological structure of the brain, leading to flashbacks months or years after use.

What Are the Effects of HPPD?

The continuous, unpredictable hallucinations of HPPD can take a serious toll on a person’s quality of life. Many people with HPPD report feeling sad, anxious, and lonely. Their hallucinatory episodes can cause insomnia, nightmares and panic attacks. They may begin to isolate themselves from others and avoid going out in public out of fear of experiencing a flashback or a panic attack.

HPPD can cause serious social or occupational impairment, interfering with the individual’s ability to maintain relationships or hold a job.

The individual may even turn to other substances, like sedatives, tranquilizers, sleeping pills, or alcohol, in an effort to manage the sensory disturbances and negative emotions of HPPD. Research published in The New Yorker indicates that up to half of individuals who are diagnosed with HPPD experience depression, and as much as 65 percent suffer from panic attacks. Some individuals with HPPD have even attempted suicide.


How Is HPPD Treated?

Research indicates that while the hallucinatory episodes of HPPD may never stop completely, they can be reduced or managed successfully. Some of the therapeutic methods used to treat this disorder include talk therapy, group therapy, and behavioral modification strategies like Cognitive Behavioral Therapy (CBT). Although psychotherapy and CBT can’t resolve the neurological effects of hallucinogenic drugs, these strategies can address the anxiety, fear and depression of HPPD. Cognitive Behavioral Therapy has been used successfully to help people with drug use disorders cope with the long-term effects of substance abuse, manage panic attacks and develop more effective ways to handle stress.

Counseling groupTalk therapy and group therapy can offer a sense of hope and provide a strong support network for individuals who have become socially isolated as a result of HPPD.

These therapeutic approaches may also be useful for individuals who need to rebuild their self-esteem and practice their social skills in a safe, supportive environment.

Several medications have proven to be effective at reducing the effects of HPPD. A study published in the Journal of International Clinical Psychopharmacology showed that treatment with a low dose of clonazepam, a sedative in the benzodiazepine family, minimized the symptoms of HPPD. A case study in Therapeutic Advances in Psychopharmacology described the successful treatment of a patient suffering from HPPD with lamotrigine (marketed as Lamictal), an anti-seizure medication. After taking lamotrigine for only a short period of time, the patient’s visual disturbances decreased significantly.

Other drugs used to treat HPPD include antidepressants and antipsychotic medications. Antidepressants may be especially useful for people experiencing depression, anxiety and isolation as a result of their disorder.

Getting Help for HPPD

The random, mind-altering hallucinations of HPPD can leave a person feeling isolated and alone; however, there are many resources available for men and women recovering from hallucinogenic drug abuse. If you, or someone you care about, are struggling with the long-term effects of substance abuse, the most important step is to reach out for help.

Residential rehab centers and outpatient programs are available for individuals seeking treatment and support for complex disorders like HPPD. Call 706-914-2327 to learn more about your treatment options.