People who have taken hallucinogens, especially stronger ones like LSD, often have flashbacks — brief recurrences of psychedelic symptoms that include visual images, “spaced-out” feelings, or other similarities to the hallucinogenic experience. It is entirely possible that even normal people have occasional little episodes like this, where memories or emotions suddenly appear from somewhere in the brain. A common occurrence is the déjà vu experience, where you feel strongly that you have lived this experience before, and can almost predict what is going to happen next.


How powerful hallucinogens like LSD work is still mostly unknown. LSD (lysergic acid diethylamide) is related to other psychedelics, including DMT (dimethyltryptamine) and psilocybin (4-phosphoryl-DMT). They affect serotonin (5-HT) and dopamine (DA) receptor sites in specialized parts of the brain. LSD somehow triggers an unusual response, opening some kind of floodgate for DA activity. It is possible that the psychedelic drug enables this floodgate to open in response to more normal neurochemistry, and that is perceived as a flashback.

Free Ride

Counselors who have treated many hallucinogen addicts or abusers have reported that most flashbacks in people who have no history of psychiatric problems are brief, not necessarily frightening, and can be turned off if necessary. Some LSD “freaks” welcome them, as a free ride. There are flashbacks that are bad trips, but they seem to occur mostly in people who are not too mentally stable.

Don’t Panic

Since flashbacks seem to involve runaway DA activity, the most important thing to do with a flashback is to avoid panic. Intense fear would only increase the available DA and reinforce the process. It would also give you a bad attitude or “set” for the experience, further insuring a bad trip. If you recognize it as harmless, it probably will be.


Support, understanding, and helpful experience can be found in any of the Twelve-Step groups that deal with drugs other than alcohol. Narcotics Anonymous is the one prevalent group.

Flashbacks, see also: Addiction, Alcohol, Alcoholism, Biochemistry, Blackouts, Narcotics Anonymous, Panic attacks, Physical aspects, Withdrawal.

Updated 7 Sep 2015

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Addictionary 2 by Jan & Judy Wilson

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