“This review illustrates the relevance of shamanism and its evolution under effects of psilocybin as a framework for identifying evolved aspects of psychedelic set and setting. effects of 5ht2 psychedelics on serotonin, stress adaptation, visual systems and personality illustrate adaptive mechanisms through which psychedelics could have enhanced hominin evolution as an environmental factor influencing selection for features of our evolved psychology. evolutionary psychology perspectives on ritual, shamanism and psychedelics provides bases for inferences regarding psychedelics’ likely roles in hominin evolution as exogenous neurotransmitter sources through their effects in selection for innate dispositions for psychedelic set and setting. psychedelics stimulate ancient brain structures and innate modular thought modules, especially self-awareness, other awareness, ‘mind reading,’ spatial and visual intelligences. the integration of these innate modules are also core features of shamanism. cross-cultural research illustrates shamanism is an empirical phenomenon of foraging societies, with its ancient basis in collective hominid displays, ritual alterations of consciousness, and endogenous healing responses. shamanic practices employed psychedelics and manipulated extrapharmacological effects through stimulation of serotonin and dopamine systems and augmenting processes of the reptilian and paleomammalian brains. differences between chimpanzee maximal displays and shamanic rituals reveal a zone of proximal development in hominin evolution. the evolution of the mimetic capacity for enactment, dance, music, and imitation provided central capacities underlying shamanic performances. other chimp-human differences in ritualized behaviors are directly related to psychedelic effects and their integration of innate modular thought processes. psychedelics and other ritual alterations of consciousness stimulate these and other innate responses such as soul flight and death-and-rebirth experiences. these findings provided bases for making inferences regarding foundations of our evolved set, setting and psychology. shamanic setting is eminently communal with singing, drumming, dancing and dramatic displays. innate modular thought structures are prominent features of the set of shamanism, exemplified in animism, animal identities, perceptions of spirits, and psychological incorporation of spirit others. a shamanic-informed psychedelic therapy includes: a preparatory set…”

“Background: observational data and preliminary studies suggest serotonin 2a agonist psychedelics may hold potential in treating a variety of substance use disorders (suds), including opioid use disorder (oud). aims: the study aim was to describe and analyze self-reported cases in which naturalistic psychedelic use was followed by cessation or reduction in other substance use. methods: an anonymous online survey of individuals reporting cessation or reduction in cannabis, opioid, or stimulant use following psychedelic use in non-clinical settings. results: four hundred forty-four respondents, mostly in the usa (67%) completed the survey. participants reported 4.5 years of problematic substance use on average before the psychedelic experience to which they attributed a reduction in drug consumption, with 79% meeting retrospective criteria for severe sud. most reported taking a moderate or high dose of lsd (43%) or psilocybin-containing mushrooms (29%), followed by significant reduction in drug consumption. before the psychedelic experience 96% met sud criteria, whereas only 27% met sud criteria afterward. participants rated their psychedelic experience as highly meaningful and insightful, with 28% endorsing psychedelic-associated changes in life priorities or values as facilitating reduced substance misuse. greater psychedelic dose, insight, mystical-type effects, and personal meaning of experiences were associated with greater reduction in drug consumption. conclusions: while these cross-sectional and self-report methods cannot determine whether psychedelics caused changes in drug use, results suggest the potential that psychedelics cause reductions in problematic substance use, and support additional clinical research on psychedelic-assisted treatment for sud.”

“Background: recent studies have suggested therapeutic benefits of psychedelics for a variety of mental health conditions. the understanding of how single psychedelic administrations can induce long-lasting effects are, in large, still lacking. however, recent studies in both healthy and clinical populations suggest a role for personality changes. aim: to test support for some of these plausible mechanisms we evaluated (cross-sectional) associations between recreational use of psychedelics and 3,4-methylene-dioxymethamphetamine (mdma) and (a) personality measures and (b) key markers of cerebral serotonergic signalling (serotonin transporter and serotonin-2a-receptor binding). methods: in 10 psychedelic-preferring recreational users, 14 mdma-preferring users and 21 non-using controls, personality was assessed using the ‘big five‘ instrument revised neo personality inventory (neo-pi-r). frontal serotonin transporter and serotonin-2a-receptor binding potentials were quantified using [11c]dasb and [18f]altanserin positron emission tomography, respectively. results: of the five neo-pi-r traits, only openness to experience scores differed between the three groups; psychedelic-preferring recreational users showing higher openness to experience scores when compared with both mdma-preferring users and controls. openness to experience scores were positively associated with lifetime number of psychedelic exposures, and among all mdma-preferring user/psychedelic-preferring recreational user individuals, frontal serotonin transporter binding – but not frontal serotonin-2a-receptor binding – was positively associated with openness to experience. conclusion: our findings from this cross-sectional study support increasing evidence of a positive association between psychedelic experiences and openness to experience, and (a) expands this to the context of “recreational” psychedelics use, and (b) links serotonergic neurotransmission to openness to experience. a modulation of personality induced by psychedelic experiences may have important therapeutic implications via its impact on peoples’ value systems, cognitive flexibility, and individual and social behaviour.”