What is a Flashback for Drug Users?

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What is a flashback? It can be a difficult experience. Claudia Burlotti/Getty Images

If you have been using drugs or spending time with drug users or people who know them, you may have heard them talking about flashbacks, and wondered what is a flashback. Flashbacks are quite a common experience among drug users, although not everyone who experiences them finds them troubling. Those that do may have Hallucinogen Persisting Perception Disorder.

Definition of a Flashback

A flashback is the sensation of re-experiencing the effects of a drug after the true effects of the drug have worn off.

Most often, flashbacks are used to describe the re-experiencing of the effects of a hallucinogenic drug, such as LSD or magic mushrooms. Flashbacks typically happen in the days or weeks following ingestion of the drug, but can happen months or even years after the drug use has been discontinued.

Sometimes, flashbacks can be intense and unpleasant, and can happen frequently, even if the person experiencing them is abstaining from drug use. Flashbacks that continue to happen in this way are a medically recognized phenomenon, which is documented in the Diagnostic and Statistical Manual of Mental Disorders (DSM 5) as Hallucinogen Persisting Perception Disorder (Flashbacks).

What Causes Flashbacks?

The experience of flashbacks is not caused by current intoxication of a hallucinogen, nor is it caused by another mental disorder, such as schizophrenia, nor by another medical condition, such as brain damage -- although all of these conditions may produce similar effects to hallucinogenic drugs, such as hallucinations and delusions.

Flashbacks can come on unpredictably or in response to a trigger, such as tiredness, anxiety or stress. Most often, this is when they are problematic for the individual experiencing them -- as the individual is feeling vulnerable due to the trigger, the out-of-control feeling of being on a drug that has not been consumed can be very confusing and upsetting.

However, the experience of a flashback can also be self-induced, by the individual thinking about the experience of tripping on a hallucinogenic drug, and this is not generally a problem. Contrary to a popular myth about LSD, flashbacks are not the result of LSD being stored in the body and re-released.

What are Flashbacks Like?

Flashbacks usually take the form of mild visual hallucinations, such as seeing geometric formations, intensified colors, and halos or trailing after-effects of images. Occasionally, people or situations may seem bizarre or ridiculous, or the person experiencing the flashback may feel disassociated. When this happens in a social situation requiring self-control, it can be embarrassing or scary for the individual experiencing it.

However, flashbacks are not usually as intense or long lasting as an actual drug experience, usually lasting just seconds or minutes, and are easier to control mentally than intoxication or a bad trip.

How to Cope with a Flashback

Having a flashback can be quite distressing, and calming or self-soothing activities can help ease the psychological discomfort that can result.

Flashbacks usually subside on their own after the drug use has been discontinued, over the course of a few months. In a flashback, the person is generally aware that they are experiencing a drug-induced effect. If the person has no insight into the drug-induced nature of their symptoms, or if these experiences persist or cause significant distress, they should seek a psychiatric assessment to determine if there is another mental health issue involved, such as psychosis. Although there is no recognized medical treatment for flashbacks, a psychologist can also help to treat the anxiety that can accompany flashbacks, giving more of a sense of self-control.


American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Fifth Edition  American Psychiatric Association, 2013.

Pronunciation: flash-back

Also Known As: Hallucinogen Persisting Perception Disorder

Examples: Ellis had a flashback the day after the effects of the LSD he had taken wore off.

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