<unk>  <unk>  is a non-psychotic<unk>  in which a person experiences apparent lasting or persistent visual hallucinations or perceptual distortions after a previous<unk> ic drug experience, usually lacking the same feelings of intoxication or mental alteration experienced while on the drug. This<unk>  usually resolves in a few weeks to several months, though more severe cases have reported life-long and greatly impairing symptoms. The hallucinations and perceptual changes consist of but are not limited to visual snow, trails and after images (palinopsia), light fractals on flat surfaces, intensified colors, altered motion<unk> , pareidolia, micropsia, and macropsia. People who have never previously taken drugs have also reported some visual anomalies associated with<unk>  (such as floaters and visual snow).<unk>  is a DSM-5 diagnosis with diagnostic code 292.89 (F16.983). For the diagnosis to be made, other psychological, psychiatric, or neurological conditions must be ruled out and it must cause distress in everyday life. In the ICD-10, the diagnosis code F16.7 corresponds most closely to the clinical picture.<unk>  is little known among both<unk>  users and psychiatrists and is often misdiagnosed as a substance-induced psychosis. Despite<unk>  being rare, many cases are temporary, resolving without the need for medication or other such treatments. However, newer research makes a distinction between<unk>  I and<unk>  II. The more drastic cases, as seen in<unk>  II, are believed to be caused by abuse of psychedelics as well as comorbid mental<unk> s. Some people who have this<unk>  report that they developed symptoms of<unk>  after their first use of such drugs (most notably LSD). Due to the nature of<unk>  being exceedingly misunderstood and under researched, few of these claims/experiences have been properly validated by the scientific community.
Hallucinogen persisting perception disorder
Pollutant-induced abnormal behaviour
Prescription drug addiction
Body substance isolation
Psychedelic microdosing
Long-term effects of cannabis
Bullying in medicine
Effects of meditation