Cannabis remains the most popular illicit psychoactive drug used in the US. Some 70-80 percent of 40- 50 year olds have tried it at least once in their lifetime and 18-19 percent of 18-21 years olds have used cannabis in the past month. There are more people in the US who meet criteria for cannabis dependence than have used cocaine in the past month or ever tried heroin; it is of further concern that the use of cannabis under medical marijuana laws continues to expand in the US as dispensaries proliferate. Trends for increased medical use may continue following, e.g., findings that smoked marijuana or a combined-cannabinoid spray can improve symptoms in multiple sclerosis. Studies have shown that acute intoxication with cannabis impairs cognitive function, however cannabidiol (CBD), a constituent of some cannabis strains, may provide some protection from the acute and lasting detrimental effects of cannabis. The studies in this project seek to determine if CBD can attenuate specific cognitive disruptions caused by D9-tetrahydrocannabinol (THC), using a nonhuman primate model. A battery of tests shown sensitive to THC will be used to determine if CBD can block the effects of both acute and chronic administration of THC. The goal is to determine the extent to which CBD might be used to moderate effects of THC in the therapeutic setting, although there are also implications for the recreational user.

Public Health Relevance

Use of marijuana (or the main active constituent D9-tetrahydrocannabinol; THC) for therapeutic purposes continues to expand and there is growing scientific evidence for specific applications in, e.g., multiple sclerosis. Evidence that cannabidil (CBD) might attenuate some adverse effects of THC, including cognitive impairment, suggests a route to possible improvement of THC-containing medical products, whether that be via development of selected high-CBD marijuana strains or synthetic drugs. The proposed studies will provide direct evidence on whether CBD has specific beneficial effects against THC-induced cognitive impairment.

National Institute of Health (NIH)
National Institute on Drug Abuse (NIDA)
Research Project (R01)
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Biobehavioral Regulation, Learning and Ethology Study Section (BRLE)
Program Officer
Su, Shelley
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Scripps Research Institute
La Jolla
United States
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Nguyen, Jacques D; Aarde, Shawn M; Vandewater, Sophia A et al. (2016) Inhaled delivery of ?(9)-tetrahydrocannabinol (THC) to rats by e-cigarette vapor technology. Neuropharmacology 109:112-120
Taffe, Michael A; Creehan, Kevin M; Vandewater, Sophia A (2015) Cannabidiol fails to reverse hypothermia or locomotor suppression induced by ?(9) -tetrahydrocannabinol in Sprague-Dawley rats. Br J Pharmacol 172:1783-91
Wright Jr, M Jerry; Taffe, Michael A (2014) Chronic periadolescent alcohol consumption produces persistent cognitive deficits in rhesus macaques. Neuropharmacology 86:78-87
Wright Jr, M Jerry; Vandewater, Sophia A; Taffe, Michael A (2013) Cannabidiol attenuates deficits of visuospatial associative memory induced by ?(9) tetrahydrocannabinol. Br J Pharmacol 170:1365-73
Wright Jr, M J; Vandewater, S A; Parsons, L H et al. (2013) ?(9)Tetrahydrocannabinol impairs reversal learning but not extra-dimensional shifts in rhesus macaques. Neuroscience 235:51-8