Hallucinogen-Related Disorders


Hallucinogens are drugs that can produce visual and auditory hallucinations and cause distortions in the perception of time and the surrounding environment. These drugs can be naturally occurring, such as psilocybin mushrooms, morning glory seeds, and peyote cactus (mescaline) or chemically synthesized, such as phencyclidine (commonly known as PCP or angel dust) ketamine, dizocilpine, LSD, and MDMA (commonly known as Molly or ecstasy).

The primary hallucinogen-related disorders include:

  • Phencyclidine-use disorder, referring to the use of phencyclidines that leads to significant impairment or distress over a 12-month period
  • Phencyclidine intoxication, referring to the problematic behavioral changes that may occur shortly after the ingestion of phencyclidine or a pharmacologically similar substance
  • Other hallucinogen–use disorder, or the use of a hallucinogen other than phencyclidine that has become problematic within a 12-month period
  • Hallucinogen persisting perception disorder (HPPD), commonly known as flashback, is diagnosed when a sober person re-experiences the perceptual disturbances, typically visual, that occurred when previously intoxicated with a hallucinogen.  


Phencyclidines, first developed for medical use as dissociative anesthetics in the 1950s, produce feelings of separation from mind and body in low doses. The most common symptoms of phencyclidine intoxication are disorientation, confusion without hallucinations, hallucinations or delusions, a catatonic-like state, and coma. Some people become belligerent, violent, impulsive, and unpredictable and have impaired judgment. Physical symptoms include rapid heartbeat, uncontrolled eye movements, numbness, and a loss of control of body movements. At high doses, these drugs can cause stupor and coma in users. Intoxication typically lasts for several hours but can persist for several days or longer.

Intoxication from a hallucinogen other than phencyclidine is evident when problematic changes in behavior or cognitive functioning occur after the ingestion of the substance. Symptoms include having a strong craving or desire to use hallucinogens, having a strong desire to cut down on hallucinogen use, or making unsuccessful efforts to do so, spending a lot of time obtaining, using, or recovering from the effects of hallucinogens, continuing to use hallucinogens despite the problems these drugs cause in major areas of life, such as work, school, home, or relationships, and needing an increasing amount of the hallucinogen to become intoxicated or reach the desired effect. The intoxication may last only minutes in the case of a drug like salvia, or several hours or longer for drugs such as LSD and MDMA.

Symptoms of hallucinogen intoxication include anxiety or depression, fear of “losing one’s mind,” paranoid thoughts, and impaired judgment. Other physiological symptoms include increased heart rate, sweating, blurring of vision, tremors, and poor coordination. Some individuals experiencing hallucinogen intoxication may take action that results in severe injury or fatality, such as attempts to “fly” from high places or reckless driving.

The mostly visual symptoms of HPPD, or flashbacks, include false perceptions of movement in the peripheral vision fields, flashes of color, or trails of images of moving objects. While short-term flashbacks may reoccur, they are generally benign and described as pleasant events. HPPD, on the other hand, is a long-lasting condition that can persist for years and can cause great distress.


Recreational drug use occurs for a variety of reasons, including unstable parenting and use of or permissive attitude toward hallucinogens by family members or friends. Hallucinogen persisting perception disorder occurs most commonly after LSD use. Development of the disorder is not linked to the frequency of hallucinogen use. This diagnosis is given only if the re-experiencing of perceptual disturbances causes significant distress or impairment. 


Treatment of hallucinogen disorder may include stress reduction and treatment of co-existing conditions such as depression or anxiety, as well as abstinence from the hallucinogen and any other substance of abuse. Small-scale studies and individual case studies have found that some symptoms of HPPD may be successfully reversed with the use of medications such naltrexone, commonly used to treat alcohol and opioid dependence; clonadine, commonly used for anxiety and hypertension; and the anti-convulsant, mood-stabilizing medication lamotrigine, commonly used to treat epilepsy and bipolar disorder.


Hermle L, Simon M, Ruchsow M et al. Hallucinogen-persisting perception disorder. Therapeutic Advances in Psychopharmacology. June 17, 2012.

American Psychiatric Association. Understanding Mental Disorders: Your Guide to DSM-5. 2015. American Psychiatric Publishing.

Last reviewed 09/22/2017