title: Psychedelic symptoms of cannabis and cocaine use as a function of trait impulsivity.
abstract: Trait impulsivity has been linked to addiction in humans. It has been suggested that drug users with high trait impulsivity levels are more sensitive to subjective drug intoxication. This study assessed whether subjective response to drugs differs between drug users with normal or high levels of trait impulsivity. Regular drug users (N = 122) received doses of cocaine HCl, cannabis, and placebo in a three-way crossover study. Their mood, dissociative state, and psychedelic symptoms were measured with subjective rating scales (CADDS, Bowdle, POMS). Trait impulsivity was assessed with the Barratt Impulsiveness Scale. Cannabis increased dissociation and psychedelic state, as well as fatigue, confusion, depression and anxiety, and decreased arousal, positive mood, vigor, friendliness, and elation. Cocaine increased dissociation, psychedelic state, vigor, friendliness, elation, positive mood, anxiety and arousal, while decreasing fatigue. Only a few subjective items revealed a drug × trait impulsivity interaction, suggesting that psychedelic symptoms were most intense in high impulsivity subjects. Trait impulsiveness ratings were negatively correlated with ratings of vigor (r = -.197) and positively correlated with ratings of loss of thought control (r = .237) during cannabis intoxication. It is concluded that a broad association between trait impulsivity and psychedelic subjective drug experience appears to be absent.
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: J H P
authors.initials: JH
authors.lastname: van Wel
authors.affiliation: Department of Psychiatry (966), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
authors.forename: D B
authors.initials: DB
authors.lastname: Spronk
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: K P C
authors.initials: KP
authors.lastname: Kuypers
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: E L
authors.initials: EL
authors.lastname: Theunissen
authors.affiliation: Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany.
authors.forename: S W
authors.initials: SW
authors.lastname: Toennes
authors.affiliation: Department of Psychiatry (966), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Verkes
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands j.ramaekers@maastrichtuniversity.nl.
authors.forename: J G
authors.initials: JG
authors.lastname: Ramaekers
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects; D002188:Cannabis / Q000737:chemistry; D003042:Cocaine / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D013759:Dronabinol / Q000494:pharmacology*; D005260:Female; D006213:Hallucinogens / Q000494:pharmacology*; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects*; D008297:Male; D055815:Young Adult
chemical_list: D006213:Hallucinogens; D013759:Dronabinol; D003042:Cocaine
keywords: Cocaine; addiction; cannabis; impulsivity; subjective intoxication