Experimental and Clinical Psychopharmacology
October 22, 2026
C Austin Zamarripa, Tory R Spindle, Dustin C Lee et al.
Co-use of smoked/vaped tobacco and cannabis is increasing with expanding legalization, yet controlled clinical studies examining mechanisms underlying co-use remain limited. This study evaluated whether acute smoked cannabis influences subsequent use ("chasing") of combustible cigarettes and e-cigarettes among people who use cannabis, cigarettes, and e-cigarettes. Twenty adults who used...
Current Neuropharmacology
August 31, 2026
Harrison J. Elder, Bryan W. Jenkins, C. Austin Zamarripa et al.
Introduction: This narrative review systematically examines the available empirical evidence for interactions between delta-9-tetrahydrocannabinol (Δ9-THC or THC) and C. sativa’s other phytochemical constituents hypothesized to underpin the popular yet controversial notion of ‘entourage effects’ experienced with botanical cannabis. Many relevant preclinical and clinical studies have been...
Psychopharmacology
August 27, 2026
Frederick S. Barrett, David Wolinsky, Zach Daily et al.
RATIONALE: Delta-9-tetrahydrocannabinol (Δ9-THC) has been reported to evoke psychedelic-like experiences at high doses in some individuals. However, the doses of Δ9-THC that occasion such effects and the phenomenology of these experiences are poorly understood. OBJECTIVES: This brief report presents preliminary findings from a pilot human laboratory study that directly compared the acute...
Neuroscience & Biobehavioral Reviews
June 3, 2026
Isabella Goodwin, Dominic Oliver, Edward Chesney et al.
Global shifts towards the liberalisation of cannabis policies have increased the potency of cannabis products, alongside their accessibility, diversity, and the number of inexperienced cannabis consumers. There is a lack of systematic evidence on the subjective effects of cannabis' main psychoactive compound, Δ9-tetrahydrocannabinol (THC). We systematically reviewed and meta-analysed data from...
JAMA Network Open
May 1, 2026
C Austin Zamarripa, Spencer Lin, Mckenna Klausner et al.
Simultaneous cannabis and alcohol use (co-use) is a public safety concern. Controlled data on the effects of co-ingestion of oral cannabis products (edibles) with alcohol are lacking, despite an increased prevalence of this behavior. To evaluate the individual and interactive effects of cannabis edibles and alcohol on simulated driving and subjective and objective impairment measures. This...
Neuropsychopharmacology
November 1, 2025
Justin C Strickland, Hayleigh E Tilton, Noah M Patton et al.
Cannabis products premixed with caffeine are increasingly present in the United States marketplace. Despite emergence of this product class, no human laboratory data have directly evaluated the isolated impact of caffeine on Δ9-tetrahydrocannabinol (Δ9-THC) effects as well as additional impacts of other common co-administered cannabinoids. This double-blind, randomized, placebo-controlled,...
Medical Cannabis and Cannabinoids
June 25, 2025
Lakshmi Kumar, Tory R Spindle, C. Austin Zamarripa et al.
Introduction: Cannabis contains hundreds of chemical constituents beyond delta-9-tetrahydrocannabinol (Δ9-THC), which is thought to be the primary driver of most of its acute pharmacodynamic effects. The entourage effect theory asserts that the pharmacological and therapeutic effects of cannabis are not solely attributable to Δ9-THC but are influenced by other constituents, such as minor...
Journal of Psychopharmacology
November 10, 2023
David Wolinsky, Frederick Streeter Barrett, Ryan Vandrey
16 citations
Cannabis and classic psychedelics are controlled substances with emerging evidence of efficacy in the treatment of a variety of psychiatric illnesses. Cannabis has largely not been regarded as having psychedelic effects in contemporary literature, despite many examples of historical use along with classic psychedelics to attain altered states of consciousness. Research into the “psychedelic”...
Drug and Alcohol Dependence
February 26, 2023
Ashley N Dowd, C Austin Zamarripa, Dennis J Sholler et al.
Background: Cannabis-infused products available for oral consumption include food and drink items (i.e., edibles) (e.g., baked goods, gummy-, chocolate-, and hard-candies, beverages/drinks) as well as non-food formulations (e.g., oils/tinctures, pills/capsules). This study characterized the motives, opinions, and subjective experiences associated with the use of these seven subtypes of oral...
JAMA Network Open
February 1, 2023
C Austin Zamarripa, Tory R Spindle, Renuka Surujunarain et al.
Controlled clinical laboratory studies have shown that cannabidiol (CBD) can sometimes attenuate or exacerbate the effects of Δ9-tetrahydrocannabinol (Δ9-THC). No studies have evaluated differences in pharmacokinetics (PK) of Δ9-THC and pharmacodynamics (PD) between orally administered cannabis extracts that vary with respect to Δ9-THC and CBD concentrations. To compare the PK and PD of orally...
JAMA Psychiatry
2023
Brian D Kiluk, Bethea A Kleykamp, Sandra D Comer et al.
22 citations
Novel treatments for opioid use disorder (OUD) are needed to address both the ongoing opioid epidemic and long-standing barriers to existing OUD treatments that target the endogenous μ-opioid receptor (MOR) system. The goal of this review is to highlight unique clinical trial design considerations for the study of emerging treatments for OUD that address targets beyond the MOR system. In...
Cannabis and Cannabinoid Research
April 2022
Marcel O Bonn-Miller, Megan Brunstetter, Alex Simonian et al.
Introduction: Given the increasing availability and use of cannabis among individuals with post-traumatic stress disorder (PTSD) and the addition of PTSD as an eligible diagnosis in several U.S. medical cannabis programs, the efficacy of dispensary-obtained cannabis needs to be thoroughly examined. Materials and Methods: This prospective study assessed PTSD symptoms and functioning every 3...
Psychopharmacology
May 1, 2019
Thomas R. Arkell, Nicholas Lintzeris, Richard C. Kevin et al.
177 citations
BACKGROUND: The main psychoactive component of cannabis, delta-9-tetrahydrocannabinol (THC), can impair driving performance. Cannabidiol (CBD), a non-intoxicating cannabis component, is thought to mitigate certain adverse effects of THC. It is possible then that cannabis containing equivalent CBD and THC will differentially affect driving and cognition relative to THC-dominant cannabis. AIMS:...
Drug and Alcohol Dependence
June 1, 2018
Nicolas J. Schlienz, Dustin C Lee, Maxine L Stitzer et al.
There is a clear need for advancing the treatment of cannabis use disorders. Prior research has demonstrated that dronabinol (oral THC) can dose-dependently suppress cannabis withdrawal and reduce the acute effects of smoked cannabis. The present study was conducted to evaluate whether high-dose dronabinol could reduce cannabis self-administration among daily users. Non-treatment seeking daily...
Cannabis and Cannabinoid Research
April 2, 2018
Muhammad Waqas, Frederick S. Barrett, Nicolas J. Schlienz et al.
37 citations
Introduction: Cannabis has been historically classified as a hallucinogen. However, subjective cannabis effects do not typically include hallucinogen-like effects. Empirical reports of hallucinogen-like effects produced by cannabis in controlled settings, particularly among healthy research volunteers, are rare and have mostly occurred after administration of purified Δ-9 tetrahydrocannabinol...
Adolescent Psychiatry
April 1, 2013
Ryan Vandrey, Matthew W Johnson, Patrick S Johnson et al.
26 citations
Over the past decade, non-medical use of novel drugs has proliferated worldwide. In most cases these are synthetic drugs first synthesized in academic or pharmaceutical laboratories for research or drug development purposes, but also include naturally occurring substances that do not fit the typical pharmacological or behavioral profile of traditional illicit substances. Perhaps most unique to...
Drug and Alcohol Dependence
February 1, 2013
Ryan Vandrey, Maxine L Stitzer, Miriam Z Mintzer et al.
Prior studies have separately examined the effects of dronabinol (oral THC) on cannabis withdrawal, cognitive performance, and the acute effects of smoked cannabis. A single study examining these clinically relevant domains would benefit the continued evaluation of dronabinol as a potential medication for the treatment of cannabis use disorders. Thirteen daily cannabis smokers completed a...
Drug and Alcohol Dependence
August 10, 2011
Ryan Vandrey, Kelly E Dunn, Jeannie A Fry et al.
Background: Synthetic cannabinoids are a rapidly emerging class of abused drugs. Synthetic cannabinoids are typically sold as "herbal blends" or "incense," commonly referred to as Spice products. No controlled human experiments have been conducted on the effects of Spice products or the synthetic cannabinoids they often contain. Methods: An internet-based survey study was conducted with adults...