Acid Flashbacks: Hallucinogen Persisting Perception Disorder

Acid flashbacks are more than just a memory for people who have used acid or other hallucinogens, such as PCP. They are a type of disturbed perception, or distorted sensory experience, which can affect the way that you see, hear, feel, taste or smell things around you. Unlike memories, which are distant ideas which you know are not happening in the present, flashbacks seem as if they are actually happening, to the extent where some drug users having flashbacks believe that they must have actually taken the drug again, or that they are going crazy.

However, most of the time when someone experiences a flashback, they are usually aware that what they are experiencing is not real, is related to a drug they took in the past, and that they have not taken the drug again. If their experience on the drug was pleasant, they may even re-experience some of the euphoria or other pleasurable feelings they got from taking the drug. However, occasionally this can backfire: if they found a particular perceptual disturbance very amusing when on LSD, they may find they are laughing inappropriately in a different social situation, in which laughter is considered inappropriate, such as at a funeral. This can cause embarrassment and distress for others as well as the person experiencing the flashback.

When flashbacks cause significant distress or feel uncontrollable, they are termed Hallucinogen Persisting Perception Disorder, a diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, or DSM-5. The symptoms of this condition include:

• Hallucinations, especially of geometric forms
• False perceptions of movement out of the corner of the eye (peripheral vision)
• Inaminate objects appearing alive, for example, walls looking as if they are breathing or growing
• Flashes of color
• Intensified color
• Trails of images of moving objects
• Afterimages
• Halos around objects
• Objects appearing larger than they are (macropsia)
• Objects appearing smaller than they are (micropsia)

Most of the time, flashbacks only last for a few minutes, and do not cause significant problems because the person knows what is happening. However, in some cases, the distortions can last for hours, weeks, months, or even years. They may occur in episodes -- the person feels normal a good deal of the time, but flashbacks can occur suddenly or unpredictably, or can be induced by the person's thinking about the drug experience. In other people, the disturbances can be more or less continuous, with the level of distress they feel as a result varying, depending on how they feel about experiencing flashbacks, whether negative feelings, such as anxiety, depression or paranoia is part of the experience, and the nature of the hallucinations they might experience.

To get an idea of the various types of flashback experiences, think of the difference between seeing the sky in a particularly vivid and intense shade or blue — perhaps with swirly patterns in the sky — versus frequently seeing snakes or spiders while hallucinating when you are already scared of these creatures.

For most LSD users, flashbacks either go away on their own or become controllable with experience. However, some people experience significant distress as a result, and find that the perceptual disturbances that are happening are overwhelming and difficult to manage. They might find it impossible to hold down a job.

For other people, what seem like acid flashbacks are a sign of a more significant mental health problem, such as substance induced psychosis, schizophrenia, or post traumatic stress disorder (PTSD). These conditions are all treatable, so it is important not to suffer in silence. See your doctor and ask for a referral to a psychiatrist or an ABAM certified physician. They will be able to diagnose your problem correctly, and give you the right treatment.

Finally, once in a while, flashbacks turn out to be caused by a physical problem, such as a migraine, a brain lesion, or a seizure disorder. These are treatable conditions, but are potentially serious if left untreated, so your doctor should also rule them out if the flashbacks continue.