While the use of magic mushrooms is generally safe with low potential for physical and psychological dependence and toxicity, attention should be given to the combined use with alcohol and the setting of use, as there is a low prevalence but unpredictable risk of panic attacks and flashbacks.

A majority of hallucinogen users may experience drug-free visual experiences that resemble hallucinogen effects, with the likelihood increasing with greater past exposure to specific hallucinogens like LSD, but only a small percentage find these symptoms distressing or impairing enough to seek treatment.

Around 4-4.5% of past psychedelic users have reported experiencing persistent, disturbing visual distortions severe enough to consider seeking treatment.

Despite the current UK legal classification system, users of psychoactive substances are relatively well informed about the associated harms, with substances like alcohol, solvents, and tobacco - despite being unclassified - rated among the top ten most harmful drugs.

Hallucinogen Persisting Perception Disorder (HPPD), a condition characterized by 'flashbacks' after hallucinogen use, is a real but rare disorder that can cause significant distress and can persist for months or years, most commonly reported after illicit LSD use, highlighting the need for further research on its prevalence, causes, and treatment.

The hallucinogenic effects of drugs like ketamine and psilocybin can lead to cognitive fragmentation and psychosis due to their ability to disrupt the brain's gating of external and internal information, resulting in an overwhelming influx of sensory and cognitive information.

While psychedelic substances like LSD can have potentially beneficial psychological effects, they can also lead to adverse reactions ranging from benign, short-lived experiences to chronic, severe conditions, and while the question of permanent changes remains controversial, it generally points to subtle or nonsignificant changes.

Hallucinogen persisting perception disorder (HPPD), often linked with anxiety, is typically due to an over-activation of neural visual pathways after drug use, and individuals with a history of anxiety, tinnitus, eye floaters, and concentration problems may be more susceptible to this condition.