Research at the CSL

If you are interested in participating in clinical research with the CSL, links to volunteer can be found under the “Read More” section of each study, or by clicking the study title.

This page is about ongoing research projects at the Cannabis Science Lab. For information about past research, please visit our Publications page.

Clinical Research Studies

This study aims to measure the effects of oral cannabis and alcohol, separately and together, on your ability to perform certain tasks such as driving, balancing, eye tracking, short-term memory, and attention. Through collecting blood and breath samples after cannabis and alcohol are taken, we will be able to see if these are markers that can predict how you do on the tasks.  The results of this study will help us better understand the effects of using cannabis and alcohol, and to help identify behaviors and/or activity in the body that relate to impairment.

  • This research is becoming more important because cannabis is becoming legal in more places and as a result, more people have access to the drug and are driving while high more often. In addition, there has been an increase in the number of people who use cannabis and alcohol at the same time. However, there is very little research to understand how using cannabis and alcohol impairs driving ability and cognitive functioning and how impairment may relate to concentrations of the drugs in blood and breath. This research will help us understand more about the impairing effects of cannabis and alcohol and inform strategies to identify impaired drivers.

    Healthy adults between the ages of 21 to 50 may join. Total possible earnings for each participant is $2660.

    If you are interested in this study, please refer to this page.

This research is being done to learn more about the short-term effects of oral nicotine pouches, including subjective and cardiovascular effects and also to understand nicotine pharmacokinetics (or how the drug moves through your body) from nicotine pouches in comparison to tobacco cigarettes. Nicotine pouches are becoming more popular and are widely available in retail stores such as tobacco shops and gas stations. However, to date, there has not been much research done to understand the effects of these pouches in tobacco cigarette smokers.

  • The purpose of this study is to learn more about the effects of using oral nicotine pouches of different flavors and nicotine strengths in comparison to regular cigarettes. If you are eligible and join this study, you will complete 1 screening visit that lasts about 2 hours and 7 drug administration sessions that each last about 5 hours.

    Healthy adults over the age of 21 may join the study. Total possible earnings will be $1030. If you are interested in this study, please refer to this page.

The purpose of this study is to learn more about the effects of oral and inhaled delta-8-tetrahydrocannabinol (∆8-THC) and delta-9-tetrahydrocannabinol (∆9-THC), which are both found in the cannabis plant. ∆8-THC is similar in its chemical structure to ∆9-THC. ∆9-THC is the main part of the cannabis plant that produces a “high,” though other chemicals like ∆8-THC may also contribute to the effects of cannabis. This research is being done to determine whether ∆8-THC products impact drug tests for cannabis (marijuana), and to measure subjective, cardiovascular, or cognitive performance effects of ∆8-THC as compared to ∆9-THC.

  • To date, there has not been much research like this conducted on oral CBG products. This research is becoming more important because there is a growing interest in the use of CBG for some health problems, and CBG products intended for oral ingestion are now widely available. This research will help us understand the effects of oral CBG. The information gained from this study will add to other studies that have been done to determine the effects of CBG by itself in healthy adults.

    If you are eligible and join this study, you will complete 1 screening visit that lasts about 2 hours and 5 drug administration visits that each last about 8 hours. During the screening phase, you will complete surveys and interviews, have laboratory tests and a physical examination to determine your study eligibility. You can earn up to $1830 for completing all portions of the study. Healthy adults between the ages of 18 and 55 may join.

    If you are interested in this study, please refer to this page.

This research is being done to learn more about the short-term effects of cannabigerol (CBG), including subjective (how you feel), cardiovascular (heart/blood), and cognitive (thinking) performance effects and also to understand CBG pharmacokinetics (or how the drug moves through the body).

  • This research is important because D-8-THC products are becoming more popular and are available across the U.S., including in states where cannabis remains illegal. However, there is little research to understand the subjective and cognitive effects of D-8-THC products or whether they can impact drug testing results for cannabis. This research will help us understand whether use of delta-8-THC will cause a positive result on drug tests that are commonly used to detect use of cannabis in the workplace and other situations. The information gained from this study will add to other studies that have been done to determine the effects of D-8-THC in healthy adults.

    Healthy adults between the ages of 18 and 45 may join. Total possible earnings will be $1810 for completing one sub-study, and $3560 for completing both sub-studies.

    If you are interested in this study, please refer to this page.

The purpose of this study is to learn more about the short-term effects of taking an oral cannabidiol (CBD) product that either contains a low level of THC, or which contains only CBD (no THC). CBD and THC are two compounds found in cannabis (marijuana).

  • This research is being done to determine whether cannabidiol (CBD) products, with and without low levels of THC, impact drug tests for cannabis (marijuana), and to measure whether these CBD products have subjective, cardiovascular, or cognitive performance effects after both short-term and long-term use. This research is becoming more important because there is a growing interest in the use of CBD for some health problems, and CBD products are now widely available. However, there is little research to understand the subjective and cognitive effects of CBD products or whether they can impact drug testing results for cannabis. This research will help us understand whether use of CBD (alone and with low levels of THC) will cause a positive result on drug tests that are commonly used to detect use of cannabis, and whether repeated use makes a difference.`

    We are currently enrolling healthy adults who are 18-55 years old. You can earn up to $830 for completing all portions of the study procedures. If you are interested in this study, please refer to this page.

This research is being done to find out the effects of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two main chemicals found in cannabis (marijuana) when used in combination with caffeine, compared to a placebo (an inactive substance that looks like the study drug, but contains no active drug).

  • Caffeine is a widely used substance seen in things like coffee, tea and soda. When used in moderation, caffeine is a safe supplement used to help with low energy, but constant consumption in high doses can lead to unwanted side effects such as anxiety, increased heart rate, and insomnia. There is evidence to suggest that cannabidiol (CBD, may lessen the negative side effects of caffeine (e.g., feeling jittery) without preventing positive or desired effects. CBD also shows potential in reducing undesirable effects of THC, such as anxiety. This study will assess the effects of combinations of THC, CBD, and caffeine.

    Study participation involves completing 1 screening visit that lasts about 2 hours and 4 drug administration visits that each last about 9 hours. During the screening phase, you will complete surveys and interviews, have laboratory tests and a physical examination to determine your study eligibility. If you are eligible and join this study, you will complete 1 screening visit that lasts about 2-3 hours and 4 study test sessions that last about 9 hours each. The test sessions will be separated by 1 week or more, depending on your schedule and the availability of the laboratory staff. If you are eligible and elect to participate, you can earn up to $1,530 for completing all portions of the study. If you are interested in this study please refer to this page.

This research is being done in collaboration with the Realm of Caring Foundation, a nonprofit organization dedicated to therapeutic cannabinoid research and education. The purpose of this research is to examine the health effects of medicinal cannabis use by surveying people who have a variety of health problems, and comparing individuals who do and don’t use cannabis. This study is open to adult patients as well as caregivers of dependent patients who have health problems and either are or are considering the use of cannabis as an alternative treatment.

  • We hope to learn more about how therapeutic use of cannabis/hemp product impacts people’s quality of life. This study involves simple questionnaires and surveys about cannabis/hemp use, other medications, and general health. Realm of Caring and Johns Hopkins use this information to improve education efforts and better understand benefits and risks of cannabis.

    You do not need to be a cannabis/hemp user to participate. To enroll, volunteers complete a questionnaire, then a shorter follow-up survey every three months. Each completed survey grants participants a choice of incentives (e.g. coupon codes or raffle entries). If you are interested in this study, please refer to this page.

The purpose of this study is to evaluate the effects of oral cannabidiol (CBD) compared to a placebo on smoking cessation.

  • People aged 18-65 years who are current daily tobacco smokers with an interest in quitting may join. The study will take place on the Johns Hopkins Bayview Medical Center campus at the Johns Hopkins Behavioral Pharmacology Research Unit. If you qualify and choose to take part in this study, compensation of up to $615 can be earned for completing all portions of the study procedures and following all study requirements.

    Study Participation consists of:

    21 experimental test sessions over the course of 6 weeks. The study will be completed in 3 phases, each lasting two weeks. Study weeks 1, 3, and 5 will be baseline weeks, during which you will smoke cigarettes as you normally would. Study weeks 2, 4, and 6 will be simulated quit attempt weeks, during which you will be asked to attempt to quit smoking cigarettes. You will be at the BPRU for up to 2 hours during each study visit, though most sessions will be about 30 minutes. If you are interested in this study, please refer to this page.

Pre-Clinical Research Studies

Our research focuses on the behavioral pharmacology of cannabis constituents, as well as terpenes found in cannabis and other natural sources, which produce pharmacological effects on their own or in interaction with cannabinoids (i.e., ‘the entourage effect’).  By testing isolated compounds and combinations in a range of behavioral tests, we aim to further understand the potential benefits and harms of cannabis and cannabis products.

Vaporized Cannabis Administration

Inhalation (vaping and smoking) is the primary route of administration for cannabis and cannabinoid products. Our group has been working on developing methods for the administration of vaporized cannabinoids, starting with THC, in rodents.

The video (left) shows passive vaporized drug administration to a freely moving rat inside of a sealed rodent cage connected to a vacuum pump for continuous air exchange. Chambers are manufactured by La Jolla Alcohol Research Inc.

Schematic (above) of the passive vapor exposure chamber

Evaluation of Cannabis Constituents for Alleviating Pain

Cannabis and certain cannabinoids have been shown to have therapeutic benefits for pain. In a recent survey of medical cannabis users, the primary reason for use was to alleviate pain (61%).  Our early studies demonstrated that acute doses of THC when vaped or ingested orally reduced pain sensitivity in a dose-related manner (although sex and strain differences were also observed). Future projects will evaluate the antinociceptive effects of other cannabis constituents.

The photo (right) shows a rat habituating on a test platform; von Frey hairs are then applied to the rat’s hindpaw in order to assess mechanical sensitivity threshold.

  • Our studies also often include screens of cannabinoids and cannabinoid combinations on standard tests of cannabinoid-receptor 1 mediated effects: the cannabinoid tetrad (tests of pain, hypothermia, locomotion, catalepsy). The test is grounded in early studies on the pharmacological validation of THC and synthetic CB1R agonists in rodents. THC and other cannabinoids produce phenotypic responses of antinociception, hypothermia, hypolocomotion, and catalepsy.

Cannabinoid Reward and Reinforcement

The abuse liability of a substance is predicted using drug reward and reinforcement procedures.  The ‘gold standard’ procedures are place conditioning and drug self-administration. Our current research is developing rodent e-vape self-administration and place conditioning models to elucidate the rewarding and/or reinforcing effects and abuse liability of cannabis constituents. These rat models can inform medication development and assessments for cannabis use disorder.

The video (left) shows a rat responding for vaporized drug delivery on a fixed-ratio 1 schedule of reinforcement. Chambers are manufactured by La Jolla Alcohol Research, Inc.

  • In a recently completed project, we assessed the conditioned rewarding effects of THC vapor in male and female rats. In this study, male and female rats showed an exposure-dependent preference for the THC vapor-paired chamber, and sex differences were observed in the THC amount needed to produce CPP, as well as the time to extinction. Conditioned place aversion was not observed at any of the THC vapor conditions tested. Read the publication here.

    In an ongoing project, we are assessing self-administration of THC vapor or propylene glycol vehicle under various schedules of reinforcement and at varying drug concentrations.

Neurocognitive Effects of Cannabis Constituents

Acute administration of cannabis and THC can produce motor and neurocognitive impairments, such as deficits in sustained attention and working memory. Neurocognitive performance after acute and chronic administration of cannabinoids using a series of tests, including the rodent Psychomotor Vigilance Test (rPVT) and the Y-Maze Spontaneous Alternation Test. The rPVT is commonly utilized as an objective risk assessment tool to quantify basic attention and neurocognitive function in laboratory, clinical, and operational settings. The Y-maze is a widely used behavioral test for studying spatial learning and memory in rodents.

Photo (right) shows a the Y-maze test.

  • In a recent study, we tested the effects of oral THC and CBD, alone and in combination, using the rodent Psychomotor Vigilance Task (rPVT). This is a sustained attention test that requires rats to monitor the location of a light stimulus that appears infrequently and to respond as quickly as possible to the onset of the light stimulus by depressing a nose-poke key; food reinforcement is earned for correct responses. A well documented side effect of acute administration of cannabis and THC is deficits in cognition and attention. CBD, a non-intoxicating constituent of cannabis, may modulate THC’s impairing effects. Read the publication here.

Ongoing projects and future work

We have multiple ongoing projects aimed at looking at effects of cannabinoids and terpenes on:

  • Anxiety and stress

  • Appetite and food intake

  • Sleep and circadian rhythms

  • Opioid dependence