CANNABIS USE

This pilot study tests whether metformin, a diabetes drug, can help protect brain white matter in young adults (18-25) with early psychosis who use cannabis. Participants will take metformin for 6 months and undergo brain scans and questionnaires. The goal is to see if this appro…

This study tests whether varenicline (Chantix), a drug already used to help people quit smoking, can also help them reduce cannabis use. Two hundred adults in South Carolina who smoke cigarettes and use cannabis will receive either varenicline or a placebo, plus counseling. The g…

This study tests a computerized task where teens push or pull a joystick in response to images, aiming to change automatic habits around cannabis and alcohol. Fifty-two participants aged 13-17 who use both substances will be followed for three months. The goal is to see if this s…

This pilot study tests a program where a clinical pharmacist talks with people with HIV about the risks of drinking alcohol (with or without cannabis) while taking multiple medications, especially those that affect the brain. The goal is to see if this approach can reduce falls a…

This study is testing a French-language iPhone app called Joint Effort 2.0 that gives personalized feedback and tips to help cannabis users adopt safer habits. About 110 adult cannabis users in Quebec will use the app for a period and report how often they use protective strategi…

This study tests whether a brief motivational interviewing session during a primary care visit can reduce alcohol and cannabis use among diverse teens aged 12 to 17. Researchers will enroll 500 participants who are at risk for substance use and track changes in how often they dri…

This study is testing whether simple saliva tests done at home can accurately show when someone has not used cannabis. Researchers will enroll 200 people aged 18-30 who use cannabis at least once a week. Participants will provide saliva and urine samples over 3-4 weeks, and resea…

This study looks at whether brain activity related to learning can predict how well teens respond to a program aimed at reducing cannabis use. Teens aged 14-17 get a brain scan, then attend 10 weekly virtual sessions where they report use and take drug tests. They can earn prizes…

This study explores whether a non-invasive brain stimulation technique called rTMS can reduce cannabis cravings in people with schizophrenia or schizoaffective disorder. Researchers will compare brain activity changes in 100 participants, including healthy cannabis users. The goa…

This study looks at how cannabis ads that claim to help with anxiety or depression affect what people buy. About 2,000 light-to-moderate cannabis users with mild to severe anxiety or depression will shop in a realistic online store. Some see ads with mental health claims, others …

This study looks at how stopping cannabis use for 28 days changes brain activity and memory in people with psychosis and in cannabis users without psychosis. Participants are randomly assigned to either quit cannabis or continue using, and undergo brain scans before and after the…

This study is investigating how common cannabis use is among lung cancer patients under 60 and whether it is linked to more aggressive tumors. Researchers will collect blood and hair samples from 150 participants across three French hospitals. The goal is to better understand if …

This study looks at how cannabis use changes brain function in teenagers who also have depression. About 280 teens will have brain scans (fMRI) and answer questionnaires at the start and again one year later, with a second year of follow-up. The goal is to understand the connecti…

This study from Johns Hopkins University is testing how different cannabis edibles—like chocolates, gummies, and drinks—affect thinking, coordination, and blood levels of THC. Forty healthy adults will each try several types of edibles in a controlled setting. The goal is to unde…

This study looks at how THC, the active part of cannabis, changes people's desire for e-cigarettes and their body's response. Researchers will give different doses of THC to 100 adults who use both e-cigarettes and cannabis, then measure how much they vape, their cravings, heart …

This study looks at how cannabis use and stopping it affect sleep, daily body rhythms, and sensitivity to light in healthy young adults aged 18-25. Researchers will compare regular cannabis users with non-users using sleep monitors, light tests, and pupil measurements. The goal i…

This study follows 200 teens aged 12-18 who use cannabis daily or near-daily and have some depression symptoms. Using smartphone surveys several times a day, researchers track cannabis use, mood, and suicidal thoughts to see how they change over time. The goal is to learn when an…

This study looks at how cannabis use changes brain connections in adults aged 50 and older. Researchers will use a special PET scan to measure synaptic density in the hippocampus, a key memory area. The goal is to understand, not treat, so no drug is given—just one scan. Results …

This study compares cannabis users and non-users during wisdom tooth removal under IV sedation. Researchers will measure how much sedative medication is needed and track vital signs like heart rate and blood pressure. The goal is to understand if cannabis use changes how people r…

This study looks at how THC, the active part of cannabis, affects cigarette cravings and smoking habits. Researchers will give 100 adults who smoke both tobacco and cannabis different doses of THC or a placebo, then measure how many cigarette puffs they take and how they feel. Th…

This study looks at what happens when people who regularly use both marijuana and tobacco use them together. Researchers will measure how much THC and nicotine get into the blood and how the body responds. The goal is to better understand the health effects of using both substanc…

This study aims to understand how young adults aged 18-24 use cannabis in their everyday lives. Over 350 regular users will report their consumption patterns, product types, and experiences through a mobile app for two years. The goal is to identify different use patterns and how…

This study looks at how alcohol and cannabis, used alone or together, change brain activity and balance. About 99 adults aged 21-50 who regularly drink and use cannabis will complete tasks while wearing EEG sensors. The goal is to better understand intoxication patterns, not to t…

This registry study is collecting real-world data from 1,000 adults with cancer who use cannabis. Participants use an app to track symptoms, cannabis use, and changes in other medications. The goal is to help patients and doctors make informed decisions about using cannabis for s…