Actively Recruiting
Brain Mechanisms Supporting Cannabis-induced Pain Relief in Adults with Chronic Low Back Pain Using Vaporized Cannabis Compared to Placebo
Led by University of California, San Diego · Updated on 2026-06-03
100
Participants Needed
1
Research Sites
8 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Chronic low back pain is a widespread and disabling condition affecting many adults, with limited effective treatments available. Researchers are studying how inhaled cannabis impacts brain activity and reduces pain in adults with chronic low back pain. This early-phase study compares cannabis containing tetrahydrocannabinol (THC) to a placebo cannabis with no THC to better understand cannabis's effects on pain and brain function. Participants will inhale 400 mg of vaporized cannabis containing 5.1% THC or placebo cannabis with less than 0.1% THC using a vaporization device under supervision. The study involves one visit during which brain imaging (fMRI), heat pain testing, and leg raise assessments are performed before and after cannabis administration. Researchers will measure pain responses and brain activity changes to evaluate cannabis's impact. During the single study session, participants will complete screening, questionnaires, and pain testing using heat stimulation on the calf. They will rate pain intensity and unpleasantness, and a straight leg raise will assess low back and leg pain. Researchers will monitor cerebral blood flow and self-reported pain, mood, sleep, stress, and cannabis-related effects using standardized questionnaires to provide a comprehensive understanding of cannabis's influence on chronic low back pain.
CONDITIONS
Brief Title
Brain Mechanisms Supporting Cannabis-induced Pain Relief
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Between 21 and 65 years old
- Cannabis free for at least 30 days before the study
- Lower back pain lasting three months or more
- Not currently taking opioids
- If female and of childbearing potential, not pregnant or nursing
- No mental or neurological conditions that impair sensory or motor functions
- No lifetime history of cannabis dependence
- No lifetime history of schizophrenia, bipolar disorder, panic disorder, or psychosis
- Prior experience with THC-containing cannabis within the past two years
- Agree not to use cannabis outside the study during participation
- Agree not to use opioids or barbiturates during participation
- Agree not to drive within 4 hours after inhaling cannabis during the study
You will not qualify if you...
- Active lung disease
- Allergy or negative past reactions to cannabis
- Positive urine drug test for THC, barbiturates, opioids, oxycodone, or methadone
- Significant illness including cardiovascular disease, diabetes, kidney or liver disease
- Current or past immunocompromising disease (e.g., lupus, psoriasis, multiple sclerosis)
- Current or past neurological conditions such as Parkinson's, dementia, seizures, or brain injury
- Current major psychiatric illness including bipolar disorder, major depression, psychosis, substance use disorder, or schizophrenia
- Current or past suicidal thoughts or attempts
- Sensitivity to thermal stimulation
- Resting blood pressure above 140/90
- Resting heart rate above 100 beats per minute
- Prisoner or institutionalized
- Claustrophobia
- MRI contraindications
- Participation in new pain management procedures within 2 weeks before or after enrollment
- History of fainting, syncope, or severe reactions to blood draws or needles
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 1 day
Participants inhale vaporized cannabis containing either active THC or placebo under supervision. Brain imaging, pain testing, and assessments are conducted before and after inhalation to evaluate pain relief and brain activity.
1 visit (in-person)
Trial Site Locations
Total: 1 location
1
Center for Functional MRI - W.M.Keck Building
La Jolla, California, United States, 92093
Actively Recruiting
Research Team
M
Madelynn Meredith, BS
Y
Yasmeen Esshaki, MA
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
2
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here