Recreational use of psychedelics is associated with elevated personality trait openness Exploration of associations with brain serotonin markers.
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. 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). 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 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 userpsychedelic-preferring recreational user individuals, frontal serotonin transporter binding - but not frontal serotonin-2A-receptor binding - was positively associated with openness to experience. 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.