hallucinogen-induced persistent perception disorder
- hallucinogen-induced persistent perception disorder
(HPPD)
Also known as hallucinogen persistent perception disorder and hallucinogen persisting perception disorder.
All three names refer to a diagnostic category characterized by a recurrence or persistence of *
entoptic phenomena and/
or *
visual hallucinations,
reminiscent of those experienced during a prior episode of intoxication with a *
hallucinogen.
The American psychophar-
macologist Henry David Abraham envisages HPPD as a perseverance of visual information,
or a disinhibition of visual information processing,
which may result in the occurrence of *
afterimages, *
trailing phenomena, *
photopsia,
and the formation of complex imagery on otherwise blank surfaces.
Other symptoms of HPPD include *
halos perceived around objects,
transient *
colour vision deficiencies, *
visual snow, *
metamorphopsias,
and *
muscae volitantes.
Eti-
ologically,
HPPD is associated primarily with the prior use of a hallucinogen,
but the syndrome has also been reported in individuals unaware of any such use.
As to the pathophysiology of HPPD,
quantitative EEG analyses (
qEEGs)
indicate that HPPD may be associated with a shortened occipital evoked potential latency.
The prognosis of HPPD is variable.
In some individuals the symptoms are self-
limiting within a relatively short time span,
while in others they may last for years.
It has been suggested that in a conceptual and phenomenological sense (
and perhaps a pathophysiological sense as well)
HPPD is related to other mnestic events,
such as drug-
related *
flashbacks, *
post-
traumatic flashbacks, *
palinopsia, *
phantompain, *
reperceptive hallucinations, *
eidetic imagery,
and *
flashbulb memories.
References
Abraham, H.D. (1983). Visual phenomenology of the LSD flashback. Archives of General Psychiatry, 40, 884-889.
ffytche, D.H. (2007). Visual hallucinatory syndromes: Past, present, and future. Dialogues in Clinical Neuroscience, 9, 173-189.
Dictionary of Hallucinations.
J.D. Blom.
2010.
Look at other dictionaries:
hallucinogen persistent perception disorder — see hallucinogen induced persistent perception disorder (HPPD) … Dictionary of Hallucinations
Hallucinogen persisting perception disorder — or HPPD is a disorder characterized by a continual presence of visual disturbances that are reminiscent of those generated by the ingestion of hallucinogenic substances. Previous use of hallucinogens is needed, though not sufficient, for… … Wikipedia
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hallucinogen hallucinosis — see hallucinogen induced persistent perception disorder … Dictionary of Hallucinations
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lysergic acid diethylamide (lsd) and hallucinations — Lysergic acid diethylamide is known under many names, including LSD, LSD 25, and acid. It is usually classified as a semi synthetic psychedelic substance of the family of ergot alkaloids, as a hallucinogen or an entheogen. The ergo tamine… … Dictionary of Hallucinations
flashback, drug related — Also known as flashback phenomenon. The introduction of the term flashback is attributed to the American psychiatrist Mardi Jon Horowitz (b. 1934). Horowitz used the term in 1969 to denote a return of hallucinations, *illusions, or * sensory… … Dictionary of Hallucinations
afterimage — Also referred to as aftersensation, afterimagery, and post image. All three terms are used to denote a group of visual percepts that occur in response to a primary light stimulus to the eye, typically noticed after the stimulus has been… … Dictionary of Hallucinations
post-traumatic flashback — Also known as revisualization. In a broad sense, the term flashback has a bearing on any experiential phenomenon that may arise either in the context of post traumatic stress disorder (PTSD) or as a consequence of the prior use of *… … Dictionary of Hallucinations
