What are Flashbacks?
Flashbacks are recurring sensory or emotional experiences that happen independently of the initial experience or event. Almost everybody experiences flashbacks of some kind, triggered by a familiar smell or sound that takes them back to a special or poignant moment. An example is re-experiencing the feeling of being back at school after smelling a familiar school smell, such as the lead of a pencil or a disinfected hallway.
In the case of drug-related flashbacks, the person usually re-experiences a visual or emotional hallucination previously seen or felt during a strong trip. This is defined by Grinspoon and Bakalaar as ‘a transitory recurrence of emotions and perceptions originally experienced while under the influence of a psychedelic drug’.1 Flashbacks are usually associated with LSD, DOM and cannabis use. Studies generally show that roughly a quarter of LSD and cannabis users experience some kind of flashback.
Such flashbacks may or may not be triggered by a sight or sound. In the most extreme cases, strong visual hallucinations occur without warning, often causing alarm. Most flashbacks are episodes of visual distortion, time distortion, physical symptoms or relived intense emotion lasting a few seconds to a few minutes.
There appear to be different types of flashbacks:
Spontaneous return of perceptual distortions
During a flashback an individual suddenly sees a familiar object in a way he or she remembers seeing while hallucinating. This may be the glowing stripes on a road or auras around people’s head.
Increased susceptibility to spontaneous imagery
This is similar to spontaneous return of perceptual distortions but involves seeing or thinking about visual imagery regularly. People who have them also say their imagery takes on a different quality – it is more vivid, seems to just spring from an unknown source and is less readily suppressed than formerly. Such flashbacks can be very vivid, involving disturbing images of animals or people. Though the distortions can live with a person for along time, the stronger animate images tend to lessen with time.
Recurrent unbidden images
Unbidden images are those that repeatedly force themselves into a person’s awareness, demanding attention and resisting efforts to dispel them. Unlike spontaneous images, these tend to be more life-like and personally threatening. They have been described by those who experience them as having ‘a will of their own’. Some people are frightened by not being able to dispel the images. Anxiety reactions, even psychotic reactions, may result.
What causes flashbacks?
Several explanations for flashbacks have been proposed. One implies deconditioning (or conditioning theory, depending on whether you regard the initial hallucination as adding or distorting the environment). Many experiences add to or change how a person sees or experiences a particular object or situation. Our brains help us see and understand all things. It follows that once we see something in a certain way, that perception will stick or re-occur every time we encounter it.