Even when the cause of the flashbacks is known, it can still be a troubling and frightening experience. Symptoms of Hallucinogens Persisting Perception Disorder Recurring hallucinations that can occur weeks, months or even years after taking a hallucinogen is the major sign of hallucinogens persisting perception disorder. read more
Causes. The cause(s) of HPPD are not yet known. It has been theorized that HPPD is an anomaly in executive function brought on by the dis-inhibition of the COMT enzyme in the breakdown of catecholamines in the brain following hallucinogen use, resulting in sensory gating disruption. read more
In addition, LSD produces tolerance to other hallucinogens, including psilocybin. On the other hand, PCP is a hallucinogen that can be addictive. People who stop repeated use of PCP experience drug cravings, headaches, and sweating as common withdrawal symptoms. read more