Clinical Research Directory

Perceptions of Proposed Warnings for Cannabis Edibles Packaging

The purpose of this study is to compare a delayed-effects warning to an expanded warning developed in previous experiments on knowledge, harm perceptions, and willingness to try cannabis edibles. Additionally, this study will examine the effects of a corresponding icon on attention to and recall of the warning.

Culturally Adapted EAET-H for Chronic Pain Patients Using Medical Cannabis in Israel - A Pilot Study

The goal of this clinical trial is to evaluate whether a culturally adapted group-based emotional therapy named "Emotional Awareness and Expression Therapy" can help reduce chronic pain and improve emotional well-being in Israeli adults who suffer from chronic musculoskeletal pain and are treated with medical cannabis. Researchers will compare patients who receive the emotional therapy along with their usual care to patients who receive usual care only, to see if the therapy leads to better outcomes in pain, mental health, and daily functioning. Participants will attend a weekly 1.5-hour group therapy session for 8 weeks; Take part in group discussions and emotional processing exercises; Complete questionnaires about pain levels, mood, sleep, and quality of life; Continue their usual medical treatment as prescribed by their doctors.

Examining the Role of Tolerance on Dose-dependent Effects of Acute THC on Oculomotor and Cognitive Performance

The purpose of this research is to determine the extent to which oculomotor function accurately detects THC-impairment, if cannabis use experience impacts this detection threshold, and to examine how the oculomotor index corresponds to a measure of sustained attention. A double-blind, placebo-controlled, within-subjects crossover design will be used to examine the dose-effects of THC (0, 5mg, 30mg) on oculomotor performance tasks and a sustained attention task in frequent and infrequent cannabis users. Results from the study will advance the investigators' understanding of the effect of THC and cannabis use frequency on oculomotor function and sustained attention, and will directly inform the validity of the investigators' oculomotor platform for identifying acute THC- induced impairment in frequent and infrequent users.

Evaluating the Impact of Psychotherapeutic Advertising Claims on Cannabis Purchasing

In the U.S., legal cannabis is frequently advertised as an effective treatment for mental health problems such as anxiety and depression-particularly online. States that have legalized cannabis have not implemented regulations to address this type of advertising. This project aims to investigate the influence of psychotherapeutic advertising claims (PAC) and mental health warning labels (WL) on online cannabis purchasing behaviors among light-to-moderate cannabis users with symptoms of depression and/or anxiety. The specific aims are to determine whether PAC increases cannabis purchasing intentions and whether a mental health WL can mitigate this effect. A realistic online cannabis shopping experience will be simulated using the digital Platform for Online Evaluation of Marijuana Marketing and Sales (POEMMS). The study will employ a between-subjects experimental design by randomizing 2,000 participants to one of four online stores that vary in PAC and WL content: (1) a control claims (CC)-only store, (2) a PAC store, (3) a WL store, and (4) a PAC + WL store. Participants will browse and select items as if making real purchases. Analyses will examine three primary outcomes to determine the influence of PAC and WL on purchasing behaviors: (1) total milligrams of THC purchased, (2) average potency (%THC) of products, and (3) overall number of products purchased. The long-term objective is to inform evidence-based cannabis policy and regulatory strategies by understanding the impact of cannabis marketing on vulnerable populations. This research is relevant to public health by addressing the potential risks associated with misleading cannabis marketing, which may lead to increased use and exacerbation of mental health symptoms among individuals with depression and anxiety. The project leverages a multidisciplinary team with expertise in addiction, mental health, epidemiology, and digital health technology. The findings have the potential to inform the development of targeted interventions and policies to reduce harms associated with cannabis advertising-ultimately contributing to better health outcomes and more effective regulation.

Investigating the Neural Correlates of Cognitive Function in Psychosis Patients and Non-Psychiatric Controls With Cannabis Use

Cognitive impairment is well established in people with psychosis and is associated with cannabis use. The current study will investigate the neurobiological basis of cognitive change associated with 28-days of cannabis abstinence in people with psychosis and non-psychiatric controls with cannabis use. Participants will be randomized to a cannabis abstinent group or a non-abstinent control group and will undergo magnetic resonance imaging at baseline and following 28-days of abstinence. This study will help characterize the neuropathophysiological processes underlying cognitive dysfunction associated with cannabis use and its recovery which may guide the development of novel interventions for problematic cannabis use.

Study on Regulated Cannabis Sales in Pharmacies

Though regulated cannabis sales are increasing, little is known about the individual health effects of cannabis regulation. Data from countries with a regulated market can be used to test the effect of regulation on the price of cannabis in the illicit market, and to explore its effect on social and health outcomes at the societal level, but strength of evidence for individual health and social outcomes is more limited because it must be aggregated on a state or country level. Data on individual and social outcomes should include baseline measurements before and outcome measurements after regulations changed. In this context, randomized-controlled trials are the least biased source of data on the effects of interventions. The SCRIPT study aims to investigate the individual health and social impact on recreational cannabis users who are allowed to purchase authorized, regulated cannabis from Swiss pharmacies compared to users who buy cannabis on the illicit market. Participants are randomly allocated in one of the two groups and followed-up for 6 months. After 6 months, all participants are allowed to participate in the intervention and the cohort is followed up for another 18 months. The intervention includes various offers: Participants can choose between cannabis sorts and delivery methods, and they are encouraged to shift from smoking cannabis to vaping cannabis-containing e-liquids, vaporizing cannabis blossoms or using oral cannabis. Vaping / vaporizing electronic devices are also recommended. At the same time, pharmacists offer opportunistic smoking cessation and problematic cannabis, alcohol use and further drug use counseling that conforms to motivational interviewing principles. The SCRIPT study adheres to rigorous quality criteria for the production and storage of regulated cannabis products. Only vaping / vaporizing electronic devices which are validated to reduce exposure to toxicants compared to cannabis smoking are recommended.

Effects of Cannabis Species Labeling and Marketing on Perceptual, Subjective and Objective Use Outcomes (Aim 2 Study)

This study looks at how cannabis product label and marketing claims affect product perceptions, use expectancies, and use intentions among inexperienced and experienced cannabis users. Participants will answer online survey questions on their perceptions of a cannabis product advertisement.

Environment and Lung Cancer

Cannabis is the most consumed drug in the world and the French are the main consumers in Europe. The most recognized effects of cannabis on human health are of a neuro-psychic nature. The medical literature on the effects of cannabis on the lung in general, and on lung carcinogenesis in particular, is most often reassuring (Tashkin, Chest 2018; Zhang, Int J Cancer 2015; Ghasemiesfe JAMA Netw. Open. 2019), despite the fact that the concentration of carcinogens in cannabis smoke is higher than that contained in tobacco smoke (Moir, Chem. Res. Toxicol. 2008), and that cannabis smoking has been implicated in the occurrence of ENT cancers. Rather, research focuses on the therapeutic effects of cannabis, especially analgesics, and even on its possible anti-tumor virtues (Abrams, Jama Oncol. 2020). These reassuring data should, however, be viewed with a great deal of caution. On the one hand, the illegal nature of cannabis in most countries and its frequent association with tobacco consumption make studies on the subject difficult and often biased. On the other hand, the daily practice of oncologists, who observe numerous cases of advanced and rapidly progressive lung cancer occurring in young patients who are heavy users of cannabis, raises suspicion of an unrecognized role of cannabis in lung carcinogenesis. In a preliminary multicenter study on French patients under 50 years of age operated for primary lung cancer (Betser, ERJ 2021), we demonstrated that cannabis consumption was extremely frequent, concerning 43% of patients, but mentioned in patients' medical records only in 4 out of 10 cases, while the smoking status was always noted. In addition, by comparing people who smoke cannabis (always here associated with tobacco) to patients who only smoke tobacco or to non-smokers, we identified a different profile of lung cancers, with more poorly differentiated tumors, presenting at a more advanced stage (more T3-T4 versus T1-T2) requiring more complex surgery, and mostly located in the upper lobes of the lung. Similar research work is currently underway at Gustave Roussy (Dr Pradere-Dr Planchard, Villejuif, France) on patients with metastatic lung cancer, with a focus on overall survival and molecular profile.

Developing and Testing an Online Intervention for Alcohol and Cannabis Misuse and Healthy Relationship Skills Among Young Adult Couples

The goal of this clinical trial is to develop and test a brief online intervention to reduce alcohol and cannabis misuse and improve healthy relationship skills among young adult couples. The main questions it aims to answer are: * Will the intervention be feasible and acceptable to young adult couples? * Will the intervention demonstrate initial efficacy in reducing risky substance use and increasing relationship functioning? Eligible couples will complete a virtual baseline session and be randomized to intervention condition (online intervention with 3-5 weeks of self-paced modules) or control condition (no intervention). Couples will complete two follow-up surveys (post-assessment - approximately 5 weeks after baseline, 3-month). Couples in the control condition will be offered the intervention after 3-month follow-up. Researchers will compare intervention and control groups to see if there there is a difference between the groups on substance misuse and relationship functioning at post-assessment and 3-month follow-up.

Effects of Pregnancy-associated Hormones on THC Metabolism in Women

Cannabis use is prevalent among pregnant women, but the effects of use on both the developing fetus and pregnant woman are unknown. Importantly, drug exposure could be influenced by the impact of pregnancy-associated hormones on the metabolism of tetrahydrocannabinol (THC), the main psychoactive component of cannabis. The goal of this study is to determine whether cortisol and estradiol - hormones that rise dramatically during pregnancy - increase the clearance of dronabinol (THC) in reproductive age women to simulate the pregnant state. The collected data will then be used to predict the time course and magnitude of changes in THC metabolism in pregnant women, particularly with gradually increasing estradiol and cortisol concentrations that evolve over the course of pregnancy. The overall objective of this study is to better understand the effects of THC use during pregnancy on the health of the pregnant woman and developing fetus.

Neuroimaging of Adolescent Cannabis Use Treatment

This study is testing whether brain activity related to learning can help predict how well teens respond to a treatment program designed to reduce cannabis use. Teens ages 14-17 will complete a brain scan and then take part in 10 weekly virtual sessions where they report cannabis use and complete drug tests at home. Participants can earn prizes for staying cannabis-free.

Characterization of Endocannabinoid and Endogenous Opioid Levels in Adolescents With Cannabis Use Disorder

This project seeks to learn more about the effects of cannabis use on the endocannabinoid system and endogenous opioid systems in adolescents to address a fundamental gap in knowledge and identify biomarkers that may help distinguish youth who relapse from youth who remain sober.

TECH App Marijuana Use Intervention for Court-Involved Adolescents

The study is about helping teens who are involved in the court system to cut down or quit using marijuana. Teens may be asked to test out an experimental smartphone app, called TECH, that will be used only by teens in this study. This app is a private online community where teens can work towards changing their substance use and other behavior with the help of other anonymous teens. We will use this information to learn how the app may help teens make a change and to improve the TECH app.

Neural and Psychiatric Consequences of Cannabis Use in Adolescents

The goal of this study is to investigate the effects of cannabis on brain function among adolescents with depression.

The Impact of Product Formulation on the Pharmacokinetics and Pharmacodynamics of Cannabis Edibles

This study will examine the pharmacokinetics and pharmacodynamics of delta-9-tetrahydrocannabinol (THC)-infused chocolates, gummies, and drinks. Healthy adults (N=40) will complete 9 drug administration sessions, including an overnight stay prior to each session. Participants will consume THC containing products in a fasted state; following drug administration, the participants will complete cognitive and psychomotor tasks, subjective assessments, have blood collected, and vital signs monitored.

Cannabis THC Potency, Metabolism, and Cognitive Impairment in Young Adults

The goal of this interventional study is to determine the impact of high potency THC product use on cognitive function of young adults aged 21-25. The main question it aims to answer is: will cannabis users who switch to less potent THC products demonstrate improved cognitive function compared to baseline? Other questions this study aims to answer include: * Can researchers accurately assess THC consumption among frequent cannabis users? * Can researchers effectively incentivize cannabis users to use less potent THC products? * Do genetic variations in THC metabolism impact urinary THC excretion? * Do genetic variations in THC metabolism impact cognitive performance in cannabis users? * Are quantitative urinary THC values predictive of cognitive impairment? * How can researchers use research findings to inform harm reduction practices for people who use cannabis? Participants will submit blood and urine samples and be incentivized to use less potent THC products.

Effect of Cannabis on E-Cigarette Use Behavior

The purpose of this study is to determine the impact of tetrahydrocannabinol (THC) administration on motivational, subjective, and physiological effects of electronic cigarettes. The study's goals are to test demand for e-cigarettes, tobacco craving, affect, heart rate, blood pressure, expired breath carbon monoxide, and cognitive performance. Researchers will compare multiple doses of THC and a placebo in participants who smoke e-cigarettes and either smoke or vape THC in the laboratory.

Cannabis Potency Effects on Brain White Matter in Early Phase Psychosis

Canada reports some of the highest rates of cannabis use in our youth and young adult populations, among all the developed countries. Recent Health Canada surveys report that 27% of 16-19-year-olds and 32% of 20-24-year-olds have used cannabis in the past 30 days, with 16-24-year-olds showing the highest rates of daily or near-daily use. Unfortunately, cannabis use has also been found to be a risk factor for the development of a psychotic disorder in emerging adults, and in those who develop psychosis and continue cannabis use, there is a significant effect on long term outcomes. This includes the severity of symptoms, risks of relapse (being hospitalized) and not reaching a level of functioning that would be expected. Lifetime experience with cannabis is greater than 80% in young adults with early phase psychosis (EPP; the first 5 years of a psychosis illness) with up to 30% of Canadian EPP patients meeting criteria for a diagnosis of cannabis use disorder (CUD) at entry to care. A recent Canadian population-based study found that cannabis use disorder associated to psychosis has risen from 3.7% pre-2018 to 10.3% at present. There has been a significant increase in Δ9-tetrahydrocannabinol (THC) levels in cannabis products available globally over the years, with popular cannabis products available start as high as 18% THC in Canada. However high potency cannabis carries a more significant risk for psychosis development, as well as higher risk for cannabis dependence and other severe mental health issues. A major gap in the research is a specific focus on cannabis potency on brain white matter (WM) in youth and young adults, and if there are any potential treatment strategies that could be used to influence any of these cannabis WM effects. To address this, a medication called metformin, that is already used in psychosis to help with side effects of antipsychotic medications, will be used as it has also shown promise to influence WM changes in other illnesses. This project is thus focused on naturalistic cannabis potency effects on WM in emerging adults in EPP (divided into three groups; those using high potency cannabis, low potency cannabis, and minimal cannabis use) and treating them with metformin for 6 months and assessing effects on neuroimaging, cognitive and clinical variables. The purpose of this pilot feasibility study is to inform the development/refinement of an intervention protocol, and not to test potential effects or mechanisms as the sample size will have insufficient power to perform an in-depth analysis. The results of this work will inform our research strategy development and assess feasibility of our novel methodological approach. Participants will: 1. Visit the clinic at baseline, 3 months (only Timeline Follow-Back Assessment administered), and 6 months post baseline to complete substance use and mental health questionnaires, and cognitive assessments 2. Complete an MRI scan at baseline and 6 months 3. Take Metformin every day for 6 months

Cannabis Effects on Sleep, Circadian Rhythms, and Light Sensitivity in Young Adults

The goal of this study is to learn how cannabis use and discontinuation affect sleep, circadian rhythms, and sensitivity to light. The main questions it aims to answer are: 1. Does cannabis use and discontinuation impact sleep drive? 2. Does cannabis use and discontinuation impact light sensitivity and circadian phase?

Cannabis-Tobacco Co-Use Treatment Study

The purpose of the RECLAIM study is to evaluate the effectiveness of varenicline (sometimes known as Chantix) compared to placebo (an inactive substance) for the treatment of cigarettes and cannabis (marijuana). Varenicline is not FDA approved for the combination treatment of cigarette abstinence and cannabis reduction or abstinence. All participants will also receive counseling and access to online treatment modules during a quit attempt for cigarettes and a reduction attempt for cannabis. This study is being conducted by the Medical University of South Carolina. All procedures are conducted remotely and there is no in-person visits are needed. To qualify, participants must be 18 or older, live in South Carolina, use cigarettes and cannabis, and are interested in quitting cigarettes and reducing cannabis.

Feasibility and Acceptability Trial to Reduce Tobacco and Cannabis Use During Pregnancy and Postpartum

Using both tobacco and cannabis during pregnancy is more common in minoritized groups and can make quitting smoking in pregnancy and remaining smoke free postpartum difficult. Investigators will test an intervention to address prenatal depressive symptoms to encourage people to quit tobacco and cannabis during pregnancy and stay quit postpartum.

Feasibility/Acceptability of a Brief Motivational Intervention for Frequent/High-Intensity Cannabis Use

The study aims to develop a novel brief motivational mobile health (mHealth) intervention for frequent and/or high-intensity cannabis use for non-collegiate young adults. A total of 120 young adults (ages 18-29, not enrolled at or attending a 4-year college or university) will be randomized to receive a mHealth intervention with text messages for five weeks or to an online resource/program with psychoeducation information about cannabis. The mHealth intervention will focus on prompting the young adult to reflect on their journey with cannabis and to reflect on their personal goals and how cannabis is reflected in these goals. Additional mini-modules are included related to topics such as motivations for use, perceived norms and tracking cannabis use. Participants will return to the program each week to reflect on the prior week and reflect on goals for the upcoming week. All participants will complete a program satisfaction survey and complete follow-up assessments at 3- and 6-months post-program.

Tobacco-Concurrent Addictions in At-Risk Youth in Ottawa

According to the 2015 Ontario Student Drug Use and Health Survey (OSDUHS), there has been a significant increase in the number of secondary school youth who use poly-substances. Not all youth have the same risk for problematic substance use. Health literature documents a high level of comorbidity between mental health and substance use, which is exacerbated in homeless youth populations. Therefore, the proposed study will focus on understanding poly-substance use among at-risk homeless school youth. As seen in substance use research and the PROMPT (2016) study (Participatory Research in Ottawa: Management and Point-of-Care for Tobacco Dependence, PI: Dr. Smita Pakhale), reduction and quitting of one substance (tobacco smoking) can lead to the reduction and quitting of other poly-substance use. A Community-Based Participatory Action Research (CBPAR) approach can help at-risk youth feel safe and comfortable enough to provide personal information about their poly-substance use and engagement with treatment or harm reduction programs. This project will be a first step in increasing health equity among at-risk homeless youth in Downtown Ottawa. The investigators aim to follow a group of at-risk youth to while providing an appropriately modified PROMPT intervention, including peers support and a licensed mental health and substance use nurse.

Study of Oral Fluid Testing Approach

The purpose of this study is to identify and evaluate oral fluid testing as a biologic measure of cannabis use days that can be assessed remotely. The researchers will conduct this fully virtual study among a community sample of 200 individuals aged 18-30 years who have used cannabis at least 1 time per week on average in the past 30 days. Participants will complete oral fluid (saliva) tests, urine tests, and Timeline Follow-back interviews (self-report) that indicate their recent cannabis use (delta-9-THC). Participants will present for 3 virtual study visits across \~3-4 weeks and be asked to complete activities in between: Study Visit 1 (Day 0; informed consent, baseline survey, TLFB interview), Study Visit 2 (\~Day 7; TLFB interview, urine testing), 6 days of at-home videorecorded oral fluid testing, Study Visit 3 (\~Day 21; TLFB interview, urine test, oral fluid test, survey, interview).