"An entheogen is a psychoactive compound, typically from natural sources such as plants or fungi, that can be used to alter consciousness for spiritual purposes (Johnstad, 2018).

"Psilocybin is a non-addictive classic psychedelic (22, 23) with neuroplasticity-inducing properties (24, 25).

"Methamphetamine is a highly addictive psychostimulant with evidence of neurotoxic properties (1–3) and is consistently ranked as one of the most harmful illicit substances—both to the person using and to society (4, 5).

"There is increasing interest in the use of ketamine as an adjunct to treatment of AUD and management of AWS. There were three studies that showed the benefit of using ketamine as an adjunctive treatment to conventional first-line therapies in patients with severe AWS. Ketamine was added to the medication regimen when AWS was refractory to BZD or after clinical signs of delirium tremens (DT). IV ketamine was administered in variable doses ranging from 0.15 to 0.75 mg/kg/h.

"The potential use of ketamine for AUD was first suggested in 1972 (32, 33).

"The non-negligible non-medical use of ketamine started to emerge in the United States of America in the 1980s, in connection with the rave dance scene, and in Western Europe in the 1990s. Hard data from that period are available only for North America and Western Europe, although the non-medical use of ketamine at alternative dance parties on beaches in Goa, India, in that early period has also been reported.¹¹¹ 

"Prevalence of past-12 month use of ketamine (another “club drug”) among 12th grade students has been below 2% for the past decade and in 2022 stood at 1.2%. This “club drug” was added to the survey in 2000. It showed little change in its usage levels through 2002. Since then use has declined in all grades. Because of the very low levels of use of this drug by 2011, questions about its use were dropped from the questionnaires administered to 8th and 10th graders."

"The use of hallucinogens was similar for college and noncollege young adults in 2022, for use in the past 12 months (5.0 vs. 8.5%), LSD (1.4% vs. 2.9%), hallucinogens other than LSD (4.6% vs. 7.2% ), MDMA (ecstasy, Molly) (1.7% vs. 2.0%), and ketamine (0.4% vs. 0.9%; Table/Figure 77)."

• "Among young adults (aged 15 to 34), recent national surveys show last year prevalence estimates for both LSD and hallucinogenic mushrooms equal to or less than 1 %. Exceptions for hallucinogenic mushrooms include Czechia (2.7 % in 2021), Finland (2.0 % in 2018), the Netherlands (1.9 % in 2021), Estonia (1.6 % in 2018, 16–34), Denmark (1.5 % in 2021), Spain (1.1 % in 2022) and Germany (1.1 % in 2021).

"Both clinical and public interest has been growing in the therapeutic use of some novel substances, particularly psychedelic substances, but also dissociative drugs such as ketamine. A growing number of clinical studies are exploring the potential of a range of psychedelic substances to treat different mental health conditions. Generalising in this area is difficult, and much of the research remains in its infancy, but some research in this area appears promising. These developments have also received considerable media attention.