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Ranganathan M, Radhakrishnan R, Addy PH, Schnakenberg-Martin AM, Williams AH, Carbuto M, Elander J, Pittman B, Andrew Sewell R, Skosnik PD, D'Souza DC. Tetrahydrocannabinol (THC) impairs encoding but not retrieval of verbal information. Prog Neuropsychopharmacol Biol Psychiatry 2017. [PMID: 28642081 DOI: 10.1016/j.pnpbp.2017.06.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Cannabis and agonists of the brain cannabinoid receptor (CB1R) produce acute memory impairments in humans. However, the extent to which cannabinoids impair the component processes of encoding and retrieval has not been established in humans. The objective of this analysis was to determine whether the administration of Δ9-Tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, impairs encoding and/or retrieval of verbal information. MATERIALS AND METHODS Healthy subjects were recruited from the community. Subjects were administered the Rey-Auditory Verbal Learning Test (RAVLT) either before administration of THC (experiment #1) (n=38) or while under the influence of THC (experiment #2) (n=57). Immediate and delayed recall on the RAVLT was compared. Subjects received intravenous THC, in a placebo-controlled, double-blind, randomized manner at doses known to produce behavioral and subjective effects consistent with cannabis intoxication. RESULTS Total immediate recall, short delayed recall, and long delayed recall were reduced in a statistically significant manner only when the RAVLT was administered to subjects while they were under the influence of THC (experiment #2) and not when the RAVLT was administered prior. CONCLUSIONS THC acutely interferes with encoding of verbal memory without interfering with retrieval. These data suggest that learning information prior to the use of cannabis or cannabinoids is not likely to disrupt recall of that information. Future studies will be necessary to determine whether THC impairs encoding of non-verbal information, to what extent THC impairs memory consolidation, and the role of other cannabinoids in the memory-impairing effects of cannabis. CLINICAL TRIAL INFORMATION Cannabinoids, Neural Synchrony, and Information Processing (THC-Gamma) http://clinicaltrials.gov/ct2/show/study/NCT00708994 NCT00708994 Pharmacogenetics of Cannabinoid Response http://clinicaltrials.gov/ct2/show/NCT00678730 NCT00678730.
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Affiliation(s)
- Mohini Ranganathan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA.
| | - Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Peter H Addy
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Medical Informatics, VA Connecticut Healthcare System, West Haven, CT, USA; Substance Abuse Treatment Unit, Connecticut Mental Health Center, New Haven, CT, USA
| | - Ashley M Schnakenberg-Martin
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Ashley H Williams
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Michelle Carbuto
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Jacqueline Elander
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - R Andrew Sewell
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Patrick D Skosnik
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
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