and dimenhydrinate (brand name dramamine) also have an anticholinergic effect. uncured tobacco is also a deliriant due to its intoxicatingly high levels of nicotine. history of use traditional religious and shamanic use main article: entheogen historically, hallucinogens have been commonly used in religious or shamanic rituals. in this context they are referred to as entheogens, and are used to facilitate healing, divination, communication with spirits, and coming-of-age ceremonies. evidence exists for the use of entheogens in prehistoric times, as well as in numerous ancient cultures, including ancient egyptian, mycenaean, ancient greek, vedic, maya, inca and aztec cultures. the upper amazon is home to the strongest extant entheogenic tradition; the urarina of the peruvian amazon, for instance, continue to practice an elaborate system of ayahuasca shamanism, coupled with an animistic belief system. shamans consume hallucinogenic substances in order to induce a trance. once in this trance, shamans believe that they are able to communicate with the spirit world, and can see what is causing their patients' illness. the aguaruna of peru believe that many illnesses are caused by the darts of sorcerers. under the influence of yaji, a hallucinogenic drink, aguaruna shamans try to discover and remove the darts from their patients. in the 1970s, frida g. surawicz and richard banta published a review of two case studies where hallucinogenic drug use appeared to play a role in "delusions of being changed into a wolf" (sometimes referred to as "lycanthropy," or being a "werewolf"). they described a patient whose delusion was thought to be caused by an altered state of consciousness "brought on by lsd and strychnine and continued casual marijuana use." the review was published in the canadian psychiatric association journal. while both central cases described white male patients from contemporary appalachia, surawicz and banta generalized their conclusions about a link between hallucinogens and "lycanthropy," based on historical accounts that reference myriad types of pharmacologically-similar drug-use alongside descriptions of "lycanthropes." early scientific investigations in an 1860 book, the mycologist mordecai cubitt cooke differentiated a class of drugs roughly corresponding to hallucinogens from opiates, and in 1924 the toxicologist louis lewin described hallucinogens in depth under the name phantastica. from the 1920s on, work in psychopharmacology and ethnobotany resulted in more detailed knowledge of various hallucinogens. in 1943, albert hofmann discovered the hallucinogenic properties of lysergic acid diethylamide (lsd), which raised the prospect of hallucinogens becoming more broadly available. hallucinogens after world war ii after world war ii there was an explosion of interest in hallucinogenic drugs in psychiatry, owing mainly to the invention of lsd. interest in the drugs tended to focus on either the potential for psychotherapeutic applications of the drugs (see psychedelic psychotherapy), or on the use of hallucinogens to produce a "controlled psychosis", in order to understand psychotic disorders such as schizophrenia. by 1951, more than 100 articles on lsd had appeared in medical journals, and by 1961, the number had increased to more than 1000 articles. at the beginning of the 1950s, the existence of hallucinogenic drugs was virtually unknown to the general public in the west. however this soon changed as several influential figures were introduced to the hallucinogenic experience. aldous huxley's 1953 essay the doors of perception, describing his experiences with mescaline, and r. gordon wasson's 1957 life magazine article ("seeking the magic mushroom") brought the topic into the public limelight. in the early 1960s, counterculture icons such as jerry garcia, timothy leary, allen ginsberg and ken kesey advocated the drugs for their psychedelic effects, and a large subculture of psychedelic drug users was spawned. psychedelic drugs played a major role in catalyzing the major social changes initiated in the 1960s. as a result of the growing popularity of lsd and disdain for the hippies with whom it was heavily associated, lsd was banned in the united states in 1967. this greatly reduced the clinical research about lsd, although limited experiments continued to take place, such as those conducted by reese jones in san francisco. as early as the 1960s, research into the medicinal properties of lsd was being conducted. "savage et al. (1962) provided the earliest report of efficacy for a hallucinogen in ocd, where after two doses of lsd, a patient who suffered from depression and violent obsessive sexual thoughts experienced dramatic and permanent improvement (nichols 2004: 164)." starting in the mid-20th century, psychedelic drugs have received extensive attention in the western world. they have been and are being explored as potential therapeutic agents in treating alcoholism, and other forms of drug addiction. legal status and attitudes in the united states, classical hallucinogens (psychedelics) are in the most strictly prohibited class of drugs, known as schedule 1 drugs. this classification was created for drugs that meet the three following characteristics: 1) they have no currently accepted medical use, 2) there is a lack of safety for their use under medical supervision, and 3) they have a high potential for abuse. however, pharmacologist david e. nichols argues that hallucinogens were placed in this class for political rather than scientific reasons. in 2006, albert hofmann, the chemist who discovered lsd, said he believed lsd could be valuable when used in a medical rather than recreational context, and said it should be regulated in the same way as morphine rather than more strictly. the netherlands previously allowed psilocybin mushrooms to be sold, but in october 2007 the dutch government moved to ban their sale following several widely publicized incidents involving tourists. in november 2020, oregon became the first u.s. state to both decriminalize psilocybin and legalize it for therapeutic use, after ballot measure 109 passed. effects relationship between long-term use and mental illness no clear connection has been made between psychedelic drugs and organic brain damage. however, hallucinogen persisting perception disorder (hppd) is a diagnosed condition wherein certain visual effects of drugs persist for a long time, sometimes permanently, although the underlying cause and pathology remains unclear. a large epidemiological study in the u.s. found that other than personality disorders and other substance use disorders, lifetime hallucinogen use was not associated with other mental disorders, and that risk of developing a hallucinogen use disorder was very low. a 2019 systematic review and meta-analysis by murrie et al. found that the transition rate from a diagnosis of hallucinogen-induced psychosis to that of schizophrenia was 26% (ci 14%-43%), which was lower than cannabis-induced psychosis (34%) but higher than amphetamine (22%), opioid (12%), alcohol (10%) and sedative (9%) induced psychoses. transition rates were not affected by sex, country of the study, hospital or community location, urban or rural setting, diagnostic methods, or duration of follow-up. in comparison, the transition rate for brief, atypical and not otherwise specified psychosis was found to be 36%. effects on the brain different classes of hallucinogens have different pharmacological mechanisms of action. psychedelics are 5-ht2a receptor agonists (serotonin 2a receptor agonists). lsd, mescaline, psilocybin, and pcp are drugs that cause hallucinations, which can alter a person's perception of reality. lsd, mescaline, and psilocybin cause their effects by initially disrupting the interaction of nerve cells and the neurotransmitter serotonin. it is distributed throughout the brain and spinal cord, where the serotonin system is involved with controlling of the behavioral, perceptual, and regulatory systems. this also includes mood, hunger, body temperature, sexual behavior, muscle control, and sensory perception. certain hallucinogens, such as pcp, act through a glutamate receptor in the brain which is important for perception of pain, responses to the environment, and learning and memory. thus far, there have been no properly controlled research studies on the specific effects of these drugs on the human brain, but smaller studies have shown some of the documented effects associated with the use of hallucinogens. psychotomimetic paradigm while early researchers believed certain hallucinogens mimicked the effects of schizophrenia, it has since been discovered that some hallucinogens resemble endogenous psychoses better than others. pcp and ketamine are known to better resemble endogenous psychoses because they reproduce both positive and negative symptoms of psychoses, while psilocybin and related hallucinogens typically produce effects resembling only the positive symptoms of schizophrenia. while the serotonergic psychedelics (lsd, psilocybin, mescaline, etc.) do produce subjective effects distinct from nmda antagonist dissociatives (pcp, ketamine, dextrorphan), there is obvious overlap in the mental processes that these drugs affect and research has discovered that there is overlap in the mechanisms by which both types of psychedelics mimic psychotic symptoms. one double-blind study examining the differences between dmt and ketamine hypothesized that classically psychedelic drugs most resemble paranoid schizophrenia while dissociative drugs best mimicked catatonic subtypes or otherwise undifferentiated schizophrenia. the researchers stated that their findings supported the view that "a heterogeneous disorder like schizophrenia is unlikely to be modeled accurately by a single pharmacological agent." chemistry classical hallucinogens (psychedelics) can be divided into three main chemical classes: tryptamines (such as psilocin), ergolines (such as lsd), and phenethylamines (such as mescaline). tryptamines closely resemble serotonin chemically.