The paradoxical psychological effects of lysergic acid diethylamide (LSD). Issue 7 (5th February 2016)

• Record Type: Journal Article
• Authors: Carhart-Harris, R. L.; Kaelen, M.; Bolstridge, M.; Williams, T. M.; Williams, L. T.; Underwood, R.; Feilding, A.; Nutt, D. J.
• Is Part Of: Psychological medicine. Volume 46:Issue 7(2016)
• Page Start: 1379
• Page End: 1390
• Publication Date: 2016-02-05
• Subjects: LSD, -- mood, -- psychedelics, -- psychosis, -- serotonin; Psychiatry -- Periodicals; Medicine and psychology -- Periodicals; Clinical psychology -- Periodicals; 616.89
• DOI: 10.1017/S0033291715002901
• Languages: English
• ISSNs: 0033-2917

Abstract

Abstract : Background: Lysergic acid diethylamide (LSD) is a potent serotonergic hallucinogen or psychedelic that modulates consciousness in a marked and novel way. This study sought to examine the acute and mid-term psychological effects of LSD in a controlled study. Method: A total of 20 healthy volunteers participated in this within-subjects study. Participants received LSD (75 µ g, intravenously) on one occasion and placebo (saline, intravenously) on another, in a balanced order, with at least 2 weeks separating sessions. Acute subjective effects were measured using the Altered States of Consciousness questionnaire and the Psychotomimetic States Inventory (PSI). A measure of optimism (the Revised Life Orientation Test), the Revised NEO Personality Inventory, and the Peter's Delusions Inventory were issued at baseline and 2 weeks after each session. Results: LSD produced robust psychological effects; including heightened mood but also high scores on the PSI, an index of psychosis-like symptoms. Increased optimism and trait openness were observed 2 weeks after LSD (and not placebo) and there were no changes in delusional thinking. Conclusions: The present findings reinforce the view that psychedelics elicit psychosis-like symptoms acutely yet improve psychological wellbeing in the mid to long term. It is proposed that acute alterations in mood are secondary to a more fundamental modulation in the quality of cognition, and that increased cognitive flexibility subsequent to serotonin 2A receptor (5-HT2A R) stimulation promotes emotional lability during intoxication and leaves a residue of 'loosened cognition' in the mid to long term that is conducive to improved psychological wellbeing.